android开发教程之使用线程实现视图平滑滚动示例

android开发教程之使用线程实现视图平滑滚动示例 改

package com.melonsapp.messenger.ui.popupuser;

import android.os.Handler;
import android.view.View;
import android.view.WindowManager;
import android.view.animation.DecelerateInterpolator;

import java.util.Timer;

/**
 * Created by lidaqiang on 17/5/3.
 */

public class SmoothScroll {
    private Handler mHandler = new Handler();
    SmoothScrollThread smoothScrollThread;
    public static int noData = 0;

    /**
     * @param v       需要操控的视图
     * @param fromX   起始Y坐标
     * @param toX     终止Y坐标
     * @param fps     帧率
     * @param durtion 动画完成时间（毫秒）
     * @desc 平滑滚动
     */
    public SmoothScroll(View v, WindowManager windowManager, WindowManager.LayoutParams windowParams, int fromX, int toX, int fps, long durtion) {
        this(v, windowManager, windowParams, fromX, toX, noData, noData, 60, durtion);
    }

    public SmoothScroll(View v, WindowManager windowManager, WindowManager.LayoutParams windowParams, int fromX, int toX, int fromY, int toY, long durtion) {
        this(v, windowManager, windowParams, fromX, toX, fromY, toY, 60, durtion);
    }

    public SmoothScroll(View v, WindowManager windowManager, WindowManager.LayoutParams windowParams, int fromX, int toX, int fromY, int toY, int fps, long durtion) {
        smoothScrollThread = new SmoothScrollThread(v, windowManager, windowParams, fromX, toX, fromY, toY, durtion, fps);
    }

    public void start() {
        if (smoothScrollThread == null) {
            return;
        }
        smoothScrollThread.run();
    }

    public void stop() {
        if (smoothScrollThread == null) {
            return;
        }
        smoothScrollThread.stop();
    }

    /**
     * @desc 平滑滚动线程，用于递归调用自己来实现某个视图的平滑滚动
     */
    class SmoothScrollThread implements Runnable {
        WindowManager mWindowManager;
        WindowManager.LayoutParams mWindowParams;
        //需要操控的视图
        private View v = null;
        //原X坐标
        private int fromX = noData;
        //目标X坐标
        private int toX = noData;

        //原Y坐标
        private int fromY = noData;
        //目标Y坐标
        private int toY = noData;
        //动画执行时间（毫秒）
        private long durtion = 0;
        //帧率
        private int fps = 60;
        //间隔时间（毫秒），间隔时间 = 1000 / 帧率
        private int interval = 0;
        //启动时间，-1 表示尚未启动
        private long startTime = -1;
        //        /减速插值器
        private DecelerateInterpolator decelerateInterpolator = null;

        private int mChangeState = 0;  // 0 x,y都不变   1 x变      2 y变   3 x,y都变

        /**
         * @desc 构造方法，做好*次配置
         */
        public SmoothScrollThread(View v, WindowManager windowManager, WindowManager.LayoutParams windowParams, int fromX, int toX, int fromY, int toY, long durtion, int fps) {
            mWindowManager = windowManager;
            mWindowParams = windowParams;
            this.v = v;
            this.fromX = fromX;
            this.toX = toX;
            this.fromY = fromY;
            this.toY = toY;
            this.durtion = durtion;
            this.fps = fps;
            this.interval = 1000 / this.fps;
            decelerateInterpolator = new DecelerateInterpolator();
            mChangeState = 0;

            if (fromX != toX && fromY == toY) {
                mChangeState = 1;
            } else if (fromX == toX && fromY != toY) {
                mChangeState = 2;
            } else if (fromX != toX && fromY != toY) {
                mChangeState = 3;
            }
        }

        @Override
        public void run() {

            if (mChangeState == 0) {
                return;
            }

            //先判断是否是*次启动，是*次启动就记录下启动的时间戳，该值仅此一次赋值
            if (startTime == -1) {
                startTime = System.currentTimeMillis();
            }
            //得到当前这个瞬间的时间戳
            long currentTime = System.currentTimeMillis();
            //放大倍数，为了扩大除法计算的浮点精度
            int enlargement = 1000;
            //算出当前这个瞬间运行到整个动画时间的百分之多少
            float rate = (currentTime - startTime) * enlargement / durtion;
            //这个比率不可能在 0 - 1 之间，放大了之后即是 0 - 1000 之间
            rate = Math.min(rate, 1000);
            //将动画的进度通过插值器得出响应的比率，乘以起始与目标坐标得出当前这个瞬间，视图应该滚动的距离。

            int currentX = fromX;
            if (mChangeState == 1 || mChangeState == 3) {
                int changeDistanceX = (int) ((fromX - toX) * decelerateInterpolator.getInterpolation(rate / enlargement));
                currentX = fromX - changeDistanceX;
            }

            int currentY = fromY;
            if (mChangeState == 2 || mChangeState == 3) {
                int changeDistanceY = (int) ((fromY - toY) * decelerateInterpolator.getInterpolation(rate / enlargement));
                currentY = fromY - changeDistanceY;
            }


            notifyViewLayout(currentX, currentY);

            if (currentX != toX || currentY != toY) {


                mHandler.postDelayed(this, this.interval);
            } else {
                return;
            }
        }


        private void notifyViewLayout(int currentX, int currentY) {
//            v.scrollTo(0, currentY);
            if (mWindowParams == null || mWindowParams == null || v == null) {
                return;
            }

            if (mChangeState == 1 || mChangeState == 3) {
                mWindowParams.x = currentX;
            }


            if (mChangeState == 2 || mChangeState == 3) {
                mWindowParams.y = currentY;
            }


            if (v.getParent() != null) {
                mWindowManager.updateViewLayout(v, mWindowParams);
            }

        }

        public void stop() {
            mHandler.removeCallbacks(this);
        }
    }


}

 

Android 屏幕适配（二）增强版百分比布局库(percent-support-lib)

dependencies {
    //...
    compile 'com.zhy:percent-support-extends:1.0.1'
}

com.zhy.android.percent.support.PercentLinearLayout
com.zhy.android.percent.support.PercentRelativeLayout
com.zhy.android.percent.support.PercentFrameLayout

<?xml version="1.0" encoding="utf-8"?>


<com.zhy.android.percent.support.PercentFrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <com.zhy.android.percent.support.PercentFrameLayout
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_gravity="center"
        android:background="#ff44aacc"
        app:layout_heightPercent="50%w"
        app:layout_widthPercent="50%w">

        <com.zhy.android.percent.support.PercentFrameLayout
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_gravity="center"
            android:background="#ffcc5ec7"
            app:layout_heightPercent="50%w"
            app:layout_widthPercent="50%w">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_gravity="center"
                android:background="#ff7ecc16"
                android:gravity="center"
                android:text="margin 15% of w"
                app:layout_marginPercent="15%w"
                />

        </com.zhy.android.percent.support.PercentFrameLayout>

    </com.zhy.android.percent.support.PercentFrameLayout>

    <TextView android:layout_width="0dp"
              android:layout_height="0dp"
              android:layout_gravity="bottom|right"
              android:background="#44ff0000"
              android:gravity="center"
              android:text="15%w,15%w"
              app:layout_heightPercent="15%w"
              app:layout_marginPercent="5%w"
              app:layout_widthPercent="15%w"/>


</com.zhy.android.percent.support.PercentFrameLayout>

<?xml version="1.0" encoding="utf-8"?>
<com.zhy.android.percent.support.PercentRelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clickable="true">

    <TextView
        android:id="@+id/row_one_item_one"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_alignParentTop="true"
        android:background="#7700ff00"
        android:text="w:70%,h:20%"
        android:gravity="center"
        app:layout_heightPercent="20%"
        app:layout_widthPercent="70%"/>

    <TextView
        android:id="@+id/row_one_item_two"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_toRightOf="@+id/row_one_item_one"
        android:background="#396190"
        android:text="w:30%,h:20%"
        app:layout_heightPercent="20%"
        android:gravity="center"
        app:layout_widthPercent="30%"/>


    <ImageView
        android:id="@+id/row_two_item_one"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:src="@drawable/tangyan"
        android:scaleType="centerCrop"
        android:layout_below="@+id/row_one_item_one"
        android:background="#d89695"
        app:layout_heightPercent="70%"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_below="@id/row_two_item_one"
        android:background="#770000ff"
        android:gravity="center"
        android:text="width:100%,height:10%"
        app:layout_heightPercent="10%"
        app:layout_widthPercent="100%"/>


</com.zhy.android.percent.support.PercentRelativeLayout>

<?xml version="1.0" encoding="utf-8"?>

<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <com.zhy.android.percent.support.PercentLinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="#ff44aacc"
            android:gravity="center"
            android:text="width:60%,height:5%,ts:3%"
            android:textColor="#ffffff"
            app:layout_heightPercent="5%"
            app:layout_marginBottomPercent="5%"
            app:layout_textSizePercent="3%"
            app:layout_widthPercent="60%"/>

        <TextView
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="#ff4400cc"
            android:gravity="center"
            android:text="width:70%,height:10%"
            android:textColor="#ffffff"
            app:layout_heightPercent="10%"
            app:layout_marginBottomPercent="5%"
            app:layout_widthPercent="70%"/>
        <TextView
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="#ff44aacc"
            android:gravity="center"
            android:text="w:80%,h:15%,textSize:5%"
            android:textColor="#ffffff"
            app:layout_heightPercent="15%"
            app:layout_marginBottomPercent="5%"
            app:layout_textSizePercent="5%"
            app:layout_widthPercent="80%"/>
        <TextView
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="#ff4400cc"
            android:gravity="center"
            android:text="width:90%,height:5%"
            android:textColor="#ffffff"
            app:layout_heightPercent="20%"
            app:layout_marginBottomPercent="5%"
            app:layout_widthPercent="90%"/>

        <TextView
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:background="#ff44aacc"
            android:gravity="center"
            android:text="width:100%,height:25%"
            android:textColor="#ffffff"
            app:layout_heightPercent="25%"
            app:layout_marginBottomPercent="5%"
            />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:background="#ff44aacc"
            android:gravity="center"
            android:text="width:100%,height:30%"
            android:textColor="#ffffff"
            app:layout_heightPercent="30%"
            app:layout_marginBottomPercent="5%"
            />


    </com.zhy.android.percent.support.PercentLinearLayout>
</ScrollView>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="PercentLayout_Layout">
        <attr name="layout_widthPercent" format="string"/>
        <attr name="layout_heightPercent" format="string"/>
        <attr name="layout_marginPercent" format="string"/>
        <attr name="layout_marginLeftPercent" format="string"/>
        <attr name="layout_marginTopPercent" format="string"/>
        <attr name="layout_marginRightPercent" format="string"/>
        <attr name="layout_marginBottomPercent" format="string"/>
        <attr name="layout_marginStartPercent" format="string"/>
        <attr name="layout_marginEndPercent" format="string"/>
        <attr name="layout_textSizePercent" format="string"/>
    </declare-styleable>
</resources>

    public static PercentLayoutInfo getPercentLayoutInfo(Context context,                                                    AttributeSet attrs)
    {
        PercentLayoutInfo info = null;
        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.PercentLayout_Layout);

        String sizeStr = array.getString(R.styleable.PercentLayout_Layout_layout_widthPercent);
        PercentLayoutInfo.PercentVal percentVal = getPercentVal(sizeStr, true);
        if (percentVal != null)
        {
            if (Log.isLoggable(TAG, Log.VERBOSE))
            {
                Log.v(TAG, "percent width: " + percentVal.percent);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.widthPercent = percentVal;
        } 

        //省略了获取其他的类似属性
        array.recycle();
        return info;
    }


    private static final String REGEX_PERCENT = "^(([0-9]+)([.]([0-9]+))?|([.]([0-9]+))?)%([wh]?)$";

    /**
     * widthStr to PercentVal
     * <br/>
     * eg: 35%w => new PercentVal(35, true)
     *
     * @param percentStr
     * @param isOnWidth
     * @return
     */
    private static PercentLayoutInfo.PercentVal getPercentVal(String percentStr, boolean isOnWidth)
    {
        //valid param
        if (percentStr == null)
        {
            return null;
        }
        Pattern p = Pattern.compile(REGEX_PERCENT);
        Matcher matcher = p.matcher(percentStr);
        if (!matcher.matches())
        {
            throw new RuntimeException("the value of layout_xxxPercent invalid! ==>" + percentStr);
        }
        int len = percentStr.length();
        //extract the float value
        String floatVal = matcher.group(1);
        String lastAlpha = percentStr.substring(len - 1);

        float percent = Float.parseFloat(floatVal) / 100f;
        boolean isBasedWidth = (isOnWidth && !lastAlpha.equals("h")) || lastAlpha.equals("w");

        return new PercentLayoutInfo.PercentVal(percent, isBasedWidth);
    }

public static class PercentVal
{

     public float percent = -1;
     public boolean isBaseWidth;

     public PercentVal(float percent, boolean isBaseWidth)
     {
          this.percent = percent;
          this.isBaseWidth = isBaseWidth;
     }
}       

 public void fillLayoutParams(ViewGroup.LayoutParams params, int widthHint,
                                     int heightHint)
        {
            // Preserve the original layout params, so we can restore them after the measure step.
            mPreservedParams.width = params.width;
            mPreservedParams.height = params.height;
            /*
            if (widthPercent >= 0) {
                params.width = (int) (widthHint * widthPercent);
            }
            if (heightPercent >= 0) {
                params.height = (int) (heightHint * heightPercent);
            }*/
            if (widthPercent != null)
            {
                int base = widthPercent.isBaseWidth ? widthHint : heightHint;
                params.width = (int) (base * widthPercent.percent);
            }
            if (heightPercent != null)
            {
                int base = heightPercent.isBaseWidth ? widthHint : heightHint;
                params.height = (int) (base * heightPercent.percent);
            }

            if (Log.isLoggable(TAG, Log.DEBUG))
            {
                Log.d(TAG, "after fillLayoutParams: (" + params.width + ", " + params.height + ")");
            }
        }

一、概述

发现android-percent-support-lib-sample这个项目，Google终于开始支持百分比的方式布局了，瞬间脉动回来，啊咧咧。对于这种历史性的时刻，不出篇文章难以表达我内心的激动。

还记得不久前，发了篇文：Android 屏幕适配方案，这篇文章以Web页面设计引出一种适配方案，*终的目的就是可以通过百分比控制控件的大小。当然了，存在一些问题，比如：

• 对于没有考虑到屏幕尺寸，可能会出现意外的情况；
• apk的大小会增加；

当然了android-percent-support这个库，基本可以解决上述问题，是不是有点小激动，稍等，我们先描述下这个support-lib。

这个库提供了：

• 两种布局供大家使用：
  PercentRelativeLayout、PercentFrameLayout，通过名字就可以看出，这是继承自FrameLayout和RelativeLayout两个容器类；
• 支持的属性有：

layout_widthPercent、layout_heightPercent、
layout_marginPercent、layout_marginLeftPercent、
layout_marginTopPercent、layout_marginRightPercent、
layout_marginBottomPercent、layout_marginStartPercent、layout_marginEndPercent。

可以看到支持宽高，以及margin。

也就是说，大家只要在开发过程中使用PercentRelativeLayout、PercentFrameLayout替换FrameLayout、RelativeLayout即可。

是不是很简单，不过貌似没有LinearLayout，有人会说LinearLayout有weight属性呀。但是，weight属性只能支持一个方向呀~~哈，没事，刚好给我们一个机会去自定义一个PercentLinearLayout。

好了，本文分为3个部分：

• PercentRelativeLayout、PercentFrameLayout的使用
• 对上述控件源码分析
• 自定义PercentLinearLayout

二、使用

关于使用，其实及其简单，并且github上也有例子，android-percent-support-lib-sample。我们就简单过一下：

首先记得在build.gradle添加：

 compile 'com.android.support:percent:22.2.0'

（一）PercentFrameLayout

<?xml version="1.0" encoding="utf-8"?>
<android.support.percent.PercentFrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_gravity="left|top"
        android:background="#44ff0000"
        android:text="width:30%,height:20%"
        app:layout_heightPercent="20%"
        android:gravity="center"
        app:layout_widthPercent="30%"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_gravity="right|top"
        android:gravity="center"
        android:background="#4400ff00"
        android:text="width:70%,height:20%"
        app:layout_heightPercent="20%"
        app:layout_widthPercent="70%"/>


    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_gravity="bottom"
        android:background="#770000ff"
        android:text="width:100%,height:10%"
        android:gravity="center"
        app:layout_heightPercent="10%"
        app:layout_widthPercent="100%"/>


</android.support.percent.PercentFrameLayout>

3个TextView，很简单，直接看效果图：

(二) PercentRelativeLayout

<?xml version="1.0" encoding="utf-8"?>
<android.support.percent.PercentRelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clickable="true">

    <TextView
        android:id="@+id/row_one_item_one"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_alignParentTop="true"
        android:background="#7700ff00"
        android:text="w:70%,h:20%"
        android:gravity="center"
        app:layout_heightPercent="20%"
        app:layout_widthPercent="70%"/>

    <TextView
        android:id="@+id/row_one_item_two"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_toRightOf="@+id/row_one_item_one"
        android:background="#396190"
        android:text="w:30%,h:20%"
        app:layout_heightPercent="20%"
        android:gravity="center"
        app:layout_widthPercent="30%"/>


    <ImageView
        android:id="@+id/row_two_item_one"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:src="@drawable/tangyan"
        android:scaleType="centerCrop"
        android:layout_below="@+id/row_one_item_one"
        android:background="#d89695"
        app:layout_heightPercent="70%"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_below="@id/row_two_item_one"
        android:background="#770000ff"
        android:gravity="center"
        android:text="width:100%,height:10%"
        app:layout_heightPercent="10%"
        app:layout_widthPercent="100%"/>


</android.support.percent.PercentRelativeLayout>

ok，依然是直接看效果图:

使用没什么好说的，就是直观的看一下。

三、源码分析

其实细想一下，Google只是对我们原本熟悉的RelativeLayout和FrameLayout进行的功能的扩展，使其支持了percent相关的属性。

那么，我们考虑下，如果是我们添加这种扩展，我们会怎么做：

• 通过LayoutParams获取child设置的percent相关属性的值
• onMeasure的时候，将child的width,height的值，通过获取的自定义属性的值进行计算（eg:容器的宽 * fraction ），计算后传入给child.measure(w,h);

ok，有了上面的猜想，我们直接看PercentFrameLayout的源码。

public class PercentFrameLayout extends FrameLayout {
    private final PercentLayoutHelper mHelper = new PercentLayoutHelper(this);

    //省略了，两个构造方法

    public PercentFrameLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }



    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new LayoutParams(getContext(), attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (mHelper.handleMeasuredStateTooSmall()) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        mHelper.restoreOriginalParams();
    }

    public static class LayoutParams extends FrameLayout.LayoutParams
            implements PercentLayoutHelper.PercentLayoutParams {
        private PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo;

        public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);
            mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
        }
        //省略了一些代码...

        @Override
        public PercentLayoutHelper.PercentLayoutInfo getPercentLayoutInfo() {
            return mPercentLayoutInfo;
        }

        @Override
        protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr) {
            PercentLayoutHelper.fetchWidthAndHeight(this, a, widthAttr, heightAttr);
        }
    }
}

代码是相当的短，可以看到PercentFrameLayout里面首先重写了generateLayoutParams方法，当然了，由于支持了一些新的layout_属性，那么肯定需要定义对应的LayoutParams。

（一）percent相关属性的获取

可以看到PercentFrameLayout.LayoutParams在原有的FrameLayout.LayoutParams基础上，实现了PercentLayoutHelper.PercentLayoutParams接口。

这个接口很简单，只有一个方法：

public interface PercentLayoutParams {
        PercentLayoutInfo getPercentLayoutInfo();
    }

而，这个方法的实现呢，也只有一行：return mPercentLayoutInfo;，那么这个mPercentLayoutInfo在哪完成赋值呢？

看PercentFrameLayout.LayoutParams的构造方法：

public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);
            mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
        }

可以看到，将attrs传入给getPercentLayoutInfo方法，那么不用说，这个方法的内部，肯定是获取自定义属性的值，然后将其封装到PercentLayoutInfo对象中，*后返回。

代码如下：

public static PercentLayoutInfo getPercentLayoutInfo(Context context,
            AttributeSet attrs) {
        PercentLayoutInfo info = null;
        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.PercentLayout_Layout);
        float value = array.getFraction(R.styleable.PercentLayout_Layout_layout_widthPercent, 1, 1,
                -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent width: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.widthPercent = value;
        }
        value = array.getFraction(R.styleable.PercentLayout_Layout_layout_heightPercent, 1, 1, -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent height: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.heightPercent = value;
        }
        value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginPercent, 1, 1, -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent margin: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.leftMarginPercent = value;
            info.topMarginPercent = value;
            info.rightMarginPercent = value;
            info.bottomMarginPercent = value;
        }
        value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginLeftPercent, 1, 1,
                -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent left margin: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.leftMarginPercent = value;
        }
        value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginTopPercent, 1, 1,
                -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent top margin: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.topMarginPercent = value;
        }
        value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginRightPercent, 1, 1,
                -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent right margin: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.rightMarginPercent = value;
        }
        value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginBottomPercent, 1, 1,
                -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent bottom margin: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.bottomMarginPercent = value;
        }
        value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginStartPercent, 1, 1,
                -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent start margin: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.startMarginPercent = value;
        }
        value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginEndPercent, 1, 1,
                -1f);
        if (value != -1f) {
            if (Log.isLoggable(TAG, Log.VERBOSE)) {
                Log.v(TAG, "percent end margin: " + value);
            }
            info = info != null ? info : new PercentLayoutInfo();
            info.endMarginPercent = value;
        }
        array.recycle();
        if (Log.isLoggable(TAG, Log.DEBUG)) {
            Log.d(TAG, "constructed: " + info);
        }
        return info;
    }

是不是和我们平时的取值很类似，所有的值*终封装到PercentLayoutInfo对象中。

ok，到此我们的属性获取就介绍完成，有了这些属性，是不是onMeasure里面要进行使用呢？

(二) onMeasue中重新计算child的尺寸

@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (mHelper.handleMeasuredStateTooSmall()) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

可以看到onMeasure中的代码页很少，看来核心的代码都被封装在mHelper的方法中，我们直接看mHelper.adjustChildren方法。

/**
     * Iterates over children and changes their width and height to one calculated from percentage
     * values.
     * @param widthMeasureSpec Width MeasureSpec of the parent ViewGroup.
     * @param heightMeasureSpec Height MeasureSpec of the parent ViewGroup.
     */
    public void adjustChildren(int widthMeasureSpec, int heightMeasureSpec) {
        //...
        int widthHint = View.MeasureSpec.getSize(widthMeasureSpec);
        int heightHint = View.MeasureSpec.getSize(heightMeasureSpec);
        for (int i = 0, N = mHost.getChildCount(); i < N; i++) {
            View view = mHost.getChildAt(i);
            ViewGroup.LayoutParams params = view.getLayoutParams();

            if (params instanceof PercentLayoutParams) {
                PercentLayoutInfo info =
                        ((PercentLayoutParams) params).getPercentLayoutInfo();
                if (Log.isLoggable(TAG, Log.DEBUG)) {
                    Log.d(TAG, "using " + info);
                }
                if (info != null) {
                    if (params instanceof ViewGroup.MarginLayoutParams) {
                        info.fillMarginLayoutParams((ViewGroup.MarginLayoutParams) params,
                                widthHint, heightHint);
                    } else {
                        info.fillLayoutParams(params, widthHint, heightHint);
                    }
                }
            }
        }
    }

通过注释也能看出，此方法中遍历所有的孩子，通过百分比的属性重新设置其宽度和高度。

首先在widthHint、heightHint保存容器的宽、高，然后遍历所有的孩子，判断其LayoutParams是否是PercentLayoutParams类型，如果是，通过params.getPercentLayoutInfo拿出info对象。

是否还记得，上面的分析中，PercentLayoutInfo保存了percent相关属性的值。

如果info不为null，则判断是否需要处理margin；我们直接看fillLayoutParams方法（处理margin也是类似的）。

 /**
         * Fills {@code ViewGroup.LayoutParams} dimensions based on percentage values.
         */
        public void fillLayoutParams(ViewGroup.LayoutParams params, int widthHint,
                int heightHint) {
            // Preserve the original layout params, so we can restore them after the measure step.
            mPreservedParams.width = params.width;
            mPreservedParams.height = params.height;

            if (widthPercent >= 0) {
                params.width = (int) (widthHint * widthPercent);
            }
            if (heightPercent >= 0) {
                params.height = (int) (heightHint * heightPercent);
            }
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "after fillLayoutParams: (" + params.width + ", " + params.height + ")");
            }
        }

首先保存原本的width和height，然后重置params的width和height为(int) (widthHint * widthPercent)和(int) (heightHint * heightPercent);。

到此，其实我们的百分比转换就结束了，理论上就已经实现了对于百分比的支持，不过Google还考虑了一些细节。

我们回到onMeasure方法：

@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (mHelper.handleMeasuredStateTooSmall()) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

下面还有个mHelper.handleMeasuredStateTooSmall的判断，也就是说，如果你设置的百分比，*终计算出来的MeasuredSize过小的话，会进行一些操作。
代码如下：

public boolean handleMeasuredStateTooSmall() {
        boolean needsSecondMeasure = false;
        for (int i = 0, N = mHost.getChildCount(); i < N; i++) {
            View view = mHost.getChildAt(i);
            ViewGroup.LayoutParams params = view.getLayoutParams();
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "should handle measured state too small " + view + " " + params);
            }
            if (params instanceof PercentLayoutParams) {
                PercentLayoutInfo info =
                        ((PercentLayoutParams) params).getPercentLayoutInfo();
                if (info != null) {
                    if (shouldHandleMeasuredWidthTooSmall(view, info)) {
                        needsSecondMeasure = true;
                        params.width = ViewGroup.LayoutParams.WRAP_CONTENT;
                    }
                    if (shouldHandleMeasuredHeightTooSmall(view, info)) {
                        needsSecondMeasure = true;
                        params.height = ViewGroup.LayoutParams.WRAP_CONTENT;
                    }
                }
            }
        }
        if (Log.isLoggable(TAG, Log.DEBUG)) {
            Log.d(TAG, "should trigger second measure pass: " + needsSecondMeasure);
        }
        return needsSecondMeasure;
    }

首先遍历所有的孩子，拿出孩子的layoutparams，如果是PercentLayoutParams实例，则取出info。如果info不为null，调用shouldHandleMeasuredWidthTooSmall判断：

private static boolean shouldHandleMeasuredWidthTooSmall(View view, PercentLayoutInfo info) {
        int state = ViewCompat.getMeasuredWidthAndState(view) & ViewCompat.MEASURED_STATE_MASK;
        return state == ViewCompat.MEASURED_STATE_TOO_SMALL && info.widthPercent >= 0 &&
                info.mPreservedParams.width == ViewGroup.LayoutParams.WRAP_CONTENT;
    }

这里就是判断，如果你设置的measuredWidth或者measureHeight过小的话，并且你在布局文件中layout_w/h 设置的是WRAP_CONTENT的话，将params.width / height= ViewGroup.LayoutParams.WRAP_CONTENT，然后重新测量。

哈，onMeasure终于结束了~~~现在我觉得应该代码结束了吧，尺寸都设置好了，还需要干嘛么，but，你会发现onLayout也重写了，我们又不改变layout规则，在onLayout里面干什么毛线：

@Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        mHelper.restoreOriginalParams();
    }

继续看mHelper.restoreOriginalParams

 /**
     * Iterates over children and restores their original dimensions that were changed for
     * percentage values. Calling this method only makes sense if you previously called
     * {@link PercentLayoutHelper#adjustChildren(int, int)}.
     */
    public void restoreOriginalParams() {
        for (int i = 0, N = mHost.getChildCount(); i < N; i++) {
            View view = mHost.getChildAt(i);
            ViewGroup.LayoutParams params = view.getLayoutParams();
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "should restore " + view + " " + params);
            }
            if (params instanceof PercentLayoutParams) {
                PercentLayoutInfo info =
                        ((PercentLayoutParams) params).getPercentLayoutInfo();
                if (Log.isLoggable(TAG, Log.DEBUG)) {
                    Log.d(TAG, "using " + info);
                }
                if (info != null) {
                    if (params instanceof ViewGroup.MarginLayoutParams) {
                        info.restoreMarginLayoutParams((ViewGroup.MarginLayoutParams) params);
                    } else {
                        info.restoreLayoutParams(params);
                    }
                }
            }
        }
    }

噗，原来是重新恢复原本的尺寸值，也就是说onMeasure里面的对值进行了改变，测量完成后。在这个地方，将值又恢复成如果布局文件中的值，上面写的都是0。恢复很简单：

public void restoreLayoutParams(ViewGroup.LayoutParams params) {
            params.width = mPreservedParams.width;
            params.height = mPreservedParams.height;
        }

你应该没有忘在哪存的把~忘了的话，麻烦Ctrl+F ‘mPreservedParams.width’ 。

也就是说，你去打印上面写法，布局文件中view的v.getLayoutParams().width，这个值应该是0。

这里感觉略微不爽~这个0没撒用处呀，还不如不重置~~

好了，到此就分析完了，其实主要就几个步骤：

• LayoutParams中属性的获取
• onMeasure中，改变params.width为百分比计算结果，测量
• 如果测量值过小且设置的w/h是wrap_content，重新测量
• onLayout中，重置params.w/h为布局文件中编写的值

可以看到，有了RelativeLayout、FrameLayout的扩展，竟然没有LinearLayout几个意思。好在，我们的核心代码都由PercentLayoutHelper封装了，自己扩展下LinearLayout也不复杂。

三、实现PercentLinearlayout

可能有人会说，有了weight呀，但是weight能做到宽、高同时百分比赋值嘛？

好了，代码很简单，如下：

（一）PercentLinearLayout

package com.juliengenoud.percentsamples;

import android.content.Context;
import android.content.res.TypedArray;
import android.support.percent.PercentLayoutHelper;
import android.util.AttributeSet;
import android.view.ViewGroup;
import android.widget.LinearLayout;

/**
 * Created by zhy on 15/6/30.
 */
public class PercentLinearLayout extends LinearLayout
{

    private PercentLayoutHelper mPercentLayoutHelper;

    public PercentLinearLayout(Context context, AttributeSet attrs)
    {
        super(context, attrs);

        mPercentLayoutHelper = new PercentLayoutHelper(this);
    }


    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        mPercentLayoutHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (mPercentLayoutHelper.handleMeasuredStateTooSmall())
        {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b)
    {
        super.onLayout(changed, l, t, r, b);
        mPercentLayoutHelper.restoreOriginalParams();
    }

    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs)
    {
        return new LayoutParams(getContext(), attrs);
    }


    public static class LayoutParams extends LinearLayout.LayoutParams
            implements PercentLayoutHelper.PercentLayoutParams
    {
        private PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo;

        public LayoutParams(Context c, AttributeSet attrs)
        {
            super(c, attrs);
            mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
        }

        @Override
        public PercentLayoutHelper.PercentLayoutInfo getPercentLayoutInfo()
        {
            return mPercentLayoutInfo;
        }

        @Override
        protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr)
        {
            PercentLayoutHelper.fetchWidthAndHeight(this, a, widthAttr, heightAttr);
        }

        public LayoutParams(int width, int height) {
            super(width, height);
        }


        public LayoutParams(ViewGroup.LayoutParams source) {
            super(source);
        }

        public LayoutParams(MarginLayoutParams source) {
            super(source);
        }

    }

}

如果你详细看了上面的源码分析，这个代码是不是没撒解释的了~

（二）测试布局

<?xml version="1.0" encoding="utf-8"?>


<com.juliengenoud.percentsamples.PercentLinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="#ff44aacc"
        android:text="width:60%,height:5%"
        android:textColor="#ffffff"
        app:layout_heightPercent="5%"
        app:layout_marginBottomPercent="5%"
        app:layout_widthPercent="60%"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="#ff4400cc"
        android:gravity="center"
        android:textColor="#ffffff"
        android:text="width:70%,height:10%"
        app:layout_heightPercent="10%"
        app:layout_marginBottomPercent="5%"
        app:layout_widthPercent="70%"/>
    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="#ff44aacc"
        android:gravity="center"
        android:text="width:80%,height:15%"
        android:textColor="#ffffff"
        app:layout_heightPercent="15%"
        app:layout_marginBottomPercent="5%"
        app:layout_widthPercent="80%"/>
    <TextView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="#ff4400cc"
        android:gravity="center"
        android:text="width:90%,height:5%"
        android:textColor="#ffffff"
        app:layout_heightPercent="20%"
        app:layout_marginBottomPercent="10%"
        app:layout_widthPercent="90%"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:background="#ff44aacc"
        android:gravity="center"
        android:text="width:100%,height:25%"
        android:textColor="#ffffff"
        app:layout_heightPercent="25%"
        app:layout_marginBottomPercent="5%"
        />


</com.juliengenoud.percentsamples.PercentLinearLayout>

我们纵向排列的几个TextView，分别设置宽/高都为百分比，且之间的间隔为5%p。

(三)效果图

ok，到此，我们使用、源码分析、扩展PercentLinearLayout就结束了。

错误异常 （1）Android Studio错误提示：Gradle project sync failed. Basic functionality (eg. editing, debugging) will not work properly

【已解决】

Java中正则Matcher类的matches()、lookAt()和find()的区别

正则表达式的语法规则

View （二） 自定义属性 自定义属性的格式详解

自定义属性格式一共有十种；

1. reference：参考某一资源ID。

2. color：颜色值。

3. boolean：布尔值。

4. dimension：尺寸值。

5. float：浮点值。

6. integer：整型值。

7. string：字符串。

8. fraction：百分数。

9. enum：枚举值。

10. flag：位或运算。

 

1. reference：参考某一资源ID。

 

（1）属性定义：

 

            <declare-styleable name = "名称">

                   <attr name = "background" format = "reference" />

            </declare-styleable>

 

（2）属性使用：

 

        <ImageView

                     android:layout_width = "42dip"
                     android:layout_height = "42dip"
                     android:background = "@drawable/图片ID"

                     />

 

2. color：颜色值。

 

（1）属性定义：

 
            <declare-styleable name = "名称">

                   <attr name = "textColor" format = "color" />

            </declare-styleable>

 

（2）属性使用：

 <TextView
 android:layout_width = "42dip"
 android:layout_height = "42dip"
 android:textColor = "#00FF00"/>

3. boolean：布尔值。

 

（1）属性定义：

            <declare-styleable name = "名称">

             <attr name = "focusable" format = "boolean" />

            </declare-styleable>

（2）属性使用：

 

 

 <Button

                    android:layout_width = "42dip"
                    android:layout_height = "42dip"

                    android:focusable = "true"

                    />

 

 

4. dimension：尺寸值。

 

（1）属性定义：

 

 

    <declare-styleable name = "名称">

                   <attr name = "layout_width" format = "dimension" />

            </declare-styleable>

 

 

（2）属性使用：

 <Button
 android:layout_width = "42dip"                    
  android:layout_height = "42dip"
  />

5. float：浮点值。

 

（1）属性定义：

 

 

 <declare-styleable name = "AlphaAnimation">
 <attr name = "fromAlpha" format = "float" />                   
<attr name = "toAlpha" format = "float" />         
 </declare-styleable>

 

 

（2）属性使用：

 

 

   <alpha
     android:fromAlpha = "1.0"
     android:toAlpha = "0.7"                  
 />

 

 

6. integer：整型值。

 

（1）属性定义：

 

 

<declare-styleable name = "AnimatedRotateDrawable">
 <attr name = "visible" />
 <attr name = "frameDuration" format="integer" />                   
<attr name = "framesCount" format="integer" />                   
<attr name = "pivotX" />                   
<attr name = "pivotY" />                   
<attr name = "drawable" />           
</declare-styleable>

 

 

（2）属性使用：

 

            <animated-rotate
                   xmlns:android = "http://schemas.android.com/apk/res/android" 
                   android:drawable = "@drawable/图片ID" 
                   android:pivotX = "50%" 
                   android:pivotY = "50%" 
                   android:framesCount = "12"                     
                   android:frameDuration = "100"
                   />

 

 

7. string：字符串。

 

（1）属性定义：

 

 

<declare-styleable name = "MapView">
<attr name = "apiKey" format = "string" />            
</declare-styleable>

 

 

 

（2）属性使用：

 

 

<com.google.android.maps.MapView
  android:layout_width = "fill_parent"
  android:layout_height = "fill_parent"
   android:apiKey = "0jOkQ80oD1JL9C6HAja99uGXCRiS2CGjKO_bc_g"/>

 

 

8. fraction：百分数。

 

（1）属性定义：

 

 

<declare-styleable name="RotateDrawable">
 <attr name = "visible" />
 <attr name = "fromDegrees" format = "float" />
<attr name = "toDegrees" format = "float" />
<attr name = "pivotX" format = "fraction" />                   
<attr name = "pivotY" format = "fraction" />                   
<attr name = "drawable" />            
</declare-styleable>

 

 

 

（2）属性使用：

 

 

<rotate
xmlns:android = "http://schemas.android.com/apk/res/android"
android:interpolator = "@anim/动画ID"
android:fromDegrees = "0"
android:toDegrees = "360"
android:pivotX = "200%"
android:pivotY = "300%" 　　             
android:duration = "5000"
android:repeatMode = "restart"
android:repeatCount = "infinite"
/>

 

 

9. enum：枚举值。

 

（1）属性定义：

 

 

 <declare-styleable name="名称">
<attr name="orientation">                          
<enum name="horizontal" value="0" />                          
<enum name="vertical" value="1" />                  
 </attr>            
</declare-styleable>

 

 

（2）属性使用：

 

 

<LinearLayout
xmlns:android = "http://schemas.android.com/apk/res/android"
android:orientation = "vertical"                    
android:layout_width = "fill_parent"                   
android:layout_height = "fill_parent"  >            
</LinearLayout>

 

 

10. flag：位或运算。

 

（1）属性定义：

 

 

 <declare-styleable name="名称">
 <attr name="windowSoftInputMode">                            
<flag name = "stateUnspecified" value = "0" />                            
<flag name = "stateUnchanged" value = "1" />                            
<flag name = "stateHidden" value = "2" />                            
<flag name = "stateAlwaysHidden" value = "3" />                            
<flag name = "stateVisible" value = "4" />                            
<flag name = "stateAlwaysVisible" value = "5" />                            
<flag name = "adjustUnspecified" value = "0x00" />                            
<flag name = "adjustResize" value = "0x10" />                            
<flag name = "adjustPan" value = "0x20" />                            
<flag name = "adjustNothing" value = "0x30" />                     
</attr>         
</declare-styleable>

 

 

（2）属性使用：

 

 

 <activity
android:name = ".StyleAndThemeActivity"                   
android:label = "@string/app_name"
android:windowSoftInputMode = "stateUnspecified | stateUnchanged　|　stateHidden">                   
<intent-filter>                          
<action android:name = "android.intent.action.MAIN" />                          
<category android:name = "android.intent.category.LAUNCHER" />                   
</intent-filter>             
</activity>

 

 

注意：

 

属性定义时可以指定多种类型值。

 

（1）属性定义：

 

 

<declare-styleable name = "名称">
<attr name = "background" format = "reference|color" />
</declare-styleable>

 

 

（2）属性使用：

 

 

 <ImageView
android:layout_width = "42dip"
android:layout_height = "42dip"
android:background = "@drawable/图片ID|#00FF00"
/>

View （二） 自定义属性

主要有三种方法可以实现自定义属性。

方法一：不使用命名空间,不使用attrs.xml文件。通过attrs.getAttributeResourceValue方法拿到属性值

方法二： 使用命名空间, 不使用attrs.xml文件。通过attrs.getAttributeResourceValue方法拿到属性值

方法三： 使用命名空间,   使用attrs.xml文件。通过context.obtainStyledAttributes(attrs,R.styleable.ImageTextView).getString()方法拿到属性值

*种方法使用*简单，但获取的属性值多为字符串不能获取各种类型的值，第三种方法是用步骤多些，但可以获取各种类型的属性值，并且可以提供代码检错功能

*种方法，直接设置属性值，通过attrs.getAttributeResourceValue拿到这个属性值。

(1)在xml文件中设置属性值

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">
    <com.example.lenovo.custom_textview.ImageTextView1
        android:id="@+id/itv"
        iamgeBoolean="true"
        iamgeColor="#00ff00"
        iamgeDimension="100dp"
        iamgeEnum1="enum2"
        iamgeFlag="flag3"
        iamgeFloat="0.8"
        iamgeFraction="200%p"
        iamgeInteger="100"
        iamgeString="自定义属性"
        imageReference="@drawable/trash"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

 

(2)在构造函数中拿到这个值

 

package com.example.lenovo.custom_textview;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.TextView;

/**
 * Created by lenovo on 2016/2/18.
 */
public class ImageTextView1 extends TextView {
    public ImageTextView1(Context context) {
        super(context);
    }
    public ImageTextView1(Context context, AttributeSet attrs) {
        super(context, attrs);
        //可以获取所有属性值的字符串表示，int,flat,boolea,reference,string 类型能获取准确值
        String iamgeDimension = attrs.getAttributeValue(null, "iamgeDimension");
        int imageReference = attrs.getAttributeResourceValue(null, "imageReference", 0);
        if (imageReference > 0) {
            bitmap = BitmapFactory.decodeResource(getResources(), imageReference);
        }
        String iamgeColor = attrs.getAttributeValue(null, "iamgeColor");
        String iamgeString = attrs.getAttributeValue(null, "iamgeString");
        int iamgeInteger = attrs.getAttributeIntValue(null, "iamgeInteger", 0);
        float iamgeFloat = attrs.getAttributeFloatValue(null, "iamgeFloat", 0);
        boolean iamgeBoolean = attrs.getAttributeBooleanValue(null, "iamgeBoolean", false);
        String iamgeFraction = attrs.getAttributeValue(null, "iamgeFraction");
        String iamgeEnum1 = attrs.getAttributeValue(null, "iamgeEnum1");
        String iamgeFlag = attrs.getAttributeValue(null, "iamgeFlag");

        StringBuffer str = new StringBuffer();
        str.append("iamgeDimension=  " + iamgeDimension + "\n");
        str.append("imageReference=  " + imageReference + "\n");
        str.append("iamgeColor=  " + iamgeColor + "\n");
        str.append("iamgeBoolean=  " + iamgeBoolean + "\n");
        str.append("iamgeString=  " + iamgeString + "\n");
        str.append("iamgeInteger=  " + iamgeInteger + "\n");
        str.append("iamgeFloat=  " + iamgeFloat + "\n");
        str.append("iamgeFraction=  " + iamgeFraction + "\n");
        str.append("iamgeEnum1=  " + iamgeEnum1 + "\n");
        str.append("iamgeFlag=  " + iamgeFlag + "\n");
        setText(str.toString());

    }

    public ImageTextView1(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    private Bitmap bitmap;

    @Override
    public void onDraw(Canvas canvas) {
        if (bitmap != null) {
            Rect src = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

            Rect target = new Rect();
            int textHeight = (int) getTextSize();
            target.left = 0;
            target.top = (int) (getMeasuredHeight() - getTextSize()) / 2 + 1;
            target.bottom = target.top + textHeight;
            target.right = (int) (textHeight * (bitmap.getWidth() / (float) bitmap.getHeight()));
            canvas.drawBitmap(bitmap, src, target, getPaint());
            canvas.translate(target.right + 2, 0);
        }

        super.onDraw(canvas);
    }


}

 

结果：

第二种方法，使用自己的命名空间，通过attrs.getAttributeResourceValue拿到这个属性值。

(1)注意在xml文件中，需要声明一个命名空间，形式一般为为http:// + 这个view的包名（其实这个名字可以随便取名只要是个名字就行，只是一般遵循这个格式）如果为http://com.example.activity，注意的是xml 中的命名空间名字要和获取属性attrs.getAttributeValue(“http://com.example.activity”, “iamgeDimension”)中的命名空间名字一样

 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:mobile="http://com.example.activity"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical"
    tools:context=".MainActivity">
    <com.example.lenovo.custom_textview.ImageTextView2
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        mobile:iamgeBoolean="true"
        mobile:iamgeColor="@color/material_blue_grey_800"
        mobile:iamgeDimension="100dp"
        mobile:iamgeEnum1="enum2"
        mobile:iamgeFlag="flag3"
        mobile:iamgeFloat="0.8"
        mobile:iamgeFraction="200%p"
        mobile:iamgeInteger="100"
        mobile:iamgeString="自定义属性"
        mobile:imageReference="@drawable/trash" />
</LinearLayout>

 

(2)通过attrs.getAttributeResourceValue，其中*个参数为命名空间。

package com.example.lenovo.custom_textview;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.TextView;

/**
 * Created by lenovo on 2016/2/18.
 */
public class ImageTextView2 extends TextView {
    public ImageTextView2(Context context) {
        super(context);
    }
    //命名空间
    private final String namespace = "http://com.example.activity";
    String tag = "ldq";
    public ImageTextView2(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public ImageTextView2(Context context, AttributeSet attrs) {
        super(context, attrs);

        //可以获取所有属性值的字符串表示，int,flat,boolea,reference,string 类型能获取准确值
        String iamgeDimension = attrs.getAttributeValue(namespace, "iamgeDimension");
        int imageReference = attrs.getAttributeResourceValue(namespace, "imageReference", 0);
        if (imageReference > 0) {
            bitmap = BitmapFactory.decodeResource(getResources(), imageReference);
        }
        String iamgeColor = attrs.getAttributeValue(namespace, "iamgeColor");
        String iamgeString = attrs.getAttributeValue(namespace, "iamgeString");
        int iamgeInteger = attrs.getAttributeIntValue(namespace, "iamgeInteger", 0);
        float iamgeFloat = attrs.getAttributeFloatValue(namespace, "iamgeFloat", 0);
        boolean iamgeBoolean = attrs.getAttributeBooleanValue(namespace, "iamgeBoolean", false);
        String iamgeFraction = attrs.getAttributeValue(namespace, "iamgeFraction");
        String iamgeEnum1 = attrs.getAttributeValue(namespace, "iamgeEnum1");
        String iamgeFlag = attrs.getAttributeValue(namespace, "iamgeFlag");

        StringBuffer str = new StringBuffer();
        str.append("iamgeDimension=  " + iamgeDimension + "\n");
        str.append("imageReference=  " + imageReference + "\n");
        str.append("iamgeColor=  " + iamgeColor + "\n");
        str.append("iamgeBoolean=  " + iamgeBoolean + "\n");
        str.append("iamgeString=  " + iamgeString + "\n");
        str.append("iamgeInteger=  " + iamgeInteger + "\n");
        str.append("iamgeFloat=  " + iamgeFloat + "\n");
        str.append("iamgeFraction=  " + iamgeFraction + "\n");
        str.append("iamgeEnum1=  " + iamgeEnum1 + "\n");
        str.append("iamgeFlag=  " + iamgeFlag + "\n");
       setText(str.toString());
    }


    private Bitmap bitmap;

    @Override
    public void onDraw(Canvas canvas) {
        if (bitmap != null) {
            Rect src = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

            Rect target = new Rect();
            int textHeight = (int) getTextSize();
            target.left = 0;
            target.top = (int) (getMeasuredHeight() - getTextSize()) / 2 + 1;
            target.bottom = target.top + textHeight;
            target.right = (int) (textHeight * (bitmap.getWidth() / (float) bitmap.getHeight()));
            canvas.drawBitmap(bitmap, src, target, getPaint());
            canvas.translate(target.right + 2, 0);
        }

        super.onDraw(canvas);
    }
}

 

结果：

第三种方法，通过自定义attrs.xml来实现 ,通过context.obtainStyledAttributes(attrs,R.styleable.ImageTextView).getString()方法拿到属性值

(1)自定义一个attrs.xml文件

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="ImageTextView">
        <attr name="iamgeDimension" format="dimension" />
        <attr name="imageReference" format="reference" />
        <attr name="iamgeColor" format="color" />
        <attr name="iamgeString" format="string" />
        <attr name="iamgeInteger" format="integer" />
        <attr name="iamgeFloat" format="float" />
        <attr name="iamgeBoolean" format="boolean" />
        <attr name="iamgeFraction" format="fraction" />
        <attr name="iamgeEnum1">
            <enum name="enum1" value="1"></enum>
            <enum name="enum2" value="2"></enum>
        </attr>
        <attr name="iamgeFlag">
            <flag name="flag1" value="1"></flag>
            <flag name="flag2" value="2"></flag>
            <flag name="flag3" value="3"></flag>
        </attr>
    </declare-styleable>
</resources>

或者

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <attr name="iamgeDimension" format="dimension" />
        <attr name="imageReference" format="reference" />
        <attr name="iamgeColor" format="color" />
        <attr name="iamgeString" format="string" />
        <attr name="iamgeInteger" format="integer" />
        <attr name="iamgeFloat" format="float" />
        <attr name="iamgeBoolean" format="boolean" />
        <attr name="iamgeFraction" format="fraction" />
        <attr name="iamgeEnum1">
            <enum name="enum1" value="1"></enum>
            <enum name="enum2" value="2"></enum>
        </attr>
        <attr name="iamgeFlag">
            <flag name="flag1" value="1"></flag>
            <flag name="flag2" value="2"></flag>
            <flag name="flag3" value="3"></flag>
        </attr>

    <declare-styleable name="ImageTextView">
       <attr name="iamgeDimension"></attr>
        <attr name="imageReference"></attr>
        <attr name="iamgeColor"></attr>
        <attr name="iamgeString"></attr>
   <attr name="iamgeInteger"></attr>
        <attr name="iamgeFloat"></attr>
        <attr name="iamgeBoolean"></attr>
        <attr name="iamgeFraction"></attr>
   <attr name="iamgeEnum1"></attr>
        <attr name="iamgeFlag"></attr>
    </declare-styleable>
</resources>

 

两种方法都可以，自定义属性分两步：

1. 定义公共属性
2. 定义控件的主题样式

如上面的xml文件*部分是公共的属性，第二部分是自定义控件MyCustomView的主题样式，该主题样式里的属性必须包含在公共属性里面。言外之意就是公共属性可以被多个自定义控件主题样式使用。

(2)在xml文件中使用这一属性，注意此时命名空间的书写规范。

 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ImageTextView="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">

    <com.example.lenovo.custom_textview.ImageTextView3
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    ImageTextView:iamgeDimension="100dp"
    ImageTextView:imageReference="@drawable/trash"
    ImageTextView:iamgeColor="@color/material_blue_grey_800"
    ImageTextView:iamgeString="自定义属性"
    ImageTextView:iamgeInteger="100"
    ImageTextView:iamgeFloat="0.8"
    ImageTextView:iamgeBoolean="true"
    ImageTextView:iamgeFraction="200%p"
    ImageTextView:iamgeEnum1="enum2"
    ImageTextView:iamgeFlag="flag3"
    />
</LinearLayout>

 

 

(3)在代码中使用context.obtainStyledAttributes获得属性值

<attr name="iamgeString" format="string" />

指 定为一个declare-styleable，而在declare-styleable 下的attr （即各属性）Android 的ADT 将会自动生成为declare-styleable的name 名字加上“_”加上对应attr（即属性名称）的名称，如上（ImageTextView_String）我们要得到Text 就需要R.styleable.ImageTextView_String，这一点的话可以看看R.java生成文件

 

package com.example.lenovo.custom_textview;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.TextView;

/**
 * Created by lenovo on 2016/2/18.
 */
public class ImageTextView3 extends TextView {
    public ImageTextView3(Context context) {
        super(context);
    }
    public ImageTextView3(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.ImageTextView);
  // TypedArray是存放资源的array,1.通过上下文得到这个数组,attrs是构造函数传进来的,对应attrs.xml  
   // 获得xml里定义的属性,格式为 名称_属性名 后面是默认值
        double iamgeDimension = typedArray.getDimension(R.styleable.ImageTextView_iamgeDimension, 0);
        int imageReference = typedArray.getResourceId(R.styleable.ImageTextView_imageReference, 0);
        bitmap = BitmapFactory.decodeResource(getResources(), imageReference);
        Drawable drawable = typedArray.getDrawable(R.styleable.ImageTextView_imageReference);
        double iamgeColor = typedArray.getColor(R.styleable.ImageTextView_iamgeColor, 0);
        String iamgeString = typedArray.getString(R.styleable.ImageTextView_iamgeString);
        double iamgeInteger = typedArray.getInteger(R.styleable.ImageTextView_iamgeInteger, 0);
        double iamgeFloat = typedArray.getFloat(R.styleable.ImageTextView_iamgeFloat, 0);
        boolean iamgeBoolean = typedArray.getBoolean(R.styleable.ImageTextView_iamgeBoolean, false);

//        ImageTextView:iamgeFraction="200%"
//        ImageTextView:iamgeFraction="200%p"
//         double iamgeFraction = typedArray.getFraction(R.styleable.ImageTextView_iamgeFraction, 4, 5, 1);
//        1）如果mageTextView_iamgeFraction 是200%，那么result就是：200%*4 ～ 8
//        2）如果mageTextView_iamgeFraction 是200%p，那么result就是：200%*5 ~ 10
        double iamgeFraction = typedArray.getFraction(R.styleable.ImageTextView_iamgeFraction, 4, 5, 1);
        double iamgeEnum1 = typedArray.getInteger(R.styleable.ImageTextView_iamgeEnum1, 0);
        double iamgeFlag = typedArray.getInteger(R.styleable.ImageTextView_iamgeFlag, 0);
   // 为了保持以后使用该属性一致性,返回一个绑定资源结束的信号给资源  
        typedArray.recycle(); //调用结束后务必调用recycle()方法，否则这次的设定会对下次的使用造成影响
        StringBuffer str = new StringBuffer();
        str.append("iamgeDimension=  " + iamgeDimension + "\n");
        str.append("imageReference=  " + imageReference + "\n");
        str.append("iamgeColor=  " + iamgeColor + "\n");
        str.append("iamgeBoolean=  " + iamgeBoolean + "\n");
        str.append("iamgeString=  " + iamgeString + "\n");
        str.append("iamgeInteger=  " + iamgeInteger + "\n");
        str.append("iamgeFloat=  " + iamgeFloat + "\n");
        str.append("iamgeFraction=  " + iamgeFraction + "\n");
        str.append("iamgeEnum1=  " + iamgeEnum1 + "\n");
        str.append("iamgeFlag=  " + iamgeFlag + "\n");
        setText(str.toString());

    }

    public ImageTextView3(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    private Bitmap bitmap;

    @Override
    public void onDraw(Canvas canvas) {
        if (bitmap != null) {
            Rect src = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

            Rect target = new Rect();
            int textHeight = (int) getTextSize();
            target.left = 0;
            target.top = (int) (getMeasuredHeight() - getTextSize()) / 2 + 1;
            target.bottom = target.top + textHeight;
            target.right = (int) (textHeight * (bitmap.getWidth() / (float) bitmap.getHeight()));
            canvas.drawBitmap(bitmap, src, target, getPaint());
            canvas.translate(target.right + 2, 0);
        }

        super.onDraw(canvas);
    }
}

结果：

总结：

这是这两种为Android 注册 属性的使用方法，那么两者有什么区别呢？

在这里我认为起码有五点，大家可以找找看还有什么区别：

• 第二种可以编译时报错，如果编程人员随便输入什么*种是不会报错的，第二种可以支持代码检测功能。
• 第二种写法，跟Android 属性标准写法是一致的，而且可以统一书法规则。
• 第二种写法，可以支持数据格式的验证，比如我们在attrs上注明只支持integer 那么就不可以使用字符串，这是*种达不到的。
• 第二种写法，可以为VIEW提供选择操作，比如如上我们使用的ENUM让VIEW对应的属性支持ENUM列表，或者为其提供BOOL等只有双项选择的操作。
• *种写法，所有的属性必须是引用自资源（不大确定，如果朋友有什么好的DEMO麻烦共享），第二种写法，可以即支持引用资源又可以直接输入做操作，为编程带来更多的方便性。

种种都说明，第二种写法更具规范性，功能更性，代码编写 也更优雅。

Android进阶笔记：AIDL内部实现详解 （二）

public class MyBinder extends Binder {
    //标记方法的
    private static final int METHOD_ADD_CODE = 1001;
    //标识binder对象的
    private static final String DESCRIPTION = "not use aidl";

    @Override
    protected boolean onTransact(int code, Parcel data, Parcel reply, int flags) throws RemoteException {
        if (code == METHOD_ADD_CODE) {
            //验证一下binder
            data.enforceInterface(DESCRIPTION);
            //从parcel对象中读取参数
            int arg0 = data.readInt();
            int arg1 = data.readInt();
            //写入结果
            reply.writeInt(add(arg0, arg1));
            return true;
        }
        return super.onTransact(code, data, reply, flags);
    }

    private int add(int arg0, int arg1) {
        return arg0 + arg1;
    }
}

public class MyService extends Service {
    private MyBinder myBinder;

    public MyService() {
    }

    @Override
    public void onCreate() {
        super.onCreate();
        //创建实例
        myBinder = new MyBinder();
    }

    @Override
    public IBinder onBind(Intent intent) {
        //返回自定义的binder对象
        return myBinder;
    }
}

public class WithoutAidlActivity extends AppCompatActivity {

    private ServiceConnection serviceConnection;
    private IBinder binder;

    //以下两个参数要和server端保持一致
    //标记方法的（告知server端调用哪个方法）
    private static final int METHOD_ADD_CODE = 1001;
    //标识binder对象的
    private static final String DESCRIPTION = "not use aidl";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_without_aidl);
        serviceConnection = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
                Log.d("onServiceConnected", "onServiceConnected: connected success！");
                binder = service;
                //这里就代替aidl中的proxy来直接调用transact方法
                //先准备参数
                Parcel data = Parcel.obtain();
                Parcel reply = Parcel.obtain();
                data.writeInterfaceToken(DESCRIPTION);
                data.writeInt(123);
                data.writeInt(456);
                try {
                    //调用transact方法
                    binder.transact(METHOD_ADD_CODE, data, reply, 0);
                    //获得结果
                    int result = reply.readInt();
                    Log.d("onServiceConnected", "result = " + result);
                } catch (RemoteException e) {
                    e.printStackTrace();
                } finally {
                    data.recycle();
                    reply.recycle();
                }
            }

            @Override
            public void onServiceDisconnected(ComponentName name) {
                binder = null;
            }
        };

        bindService(new Intent("com.coder_f.aidlserver.MyService"), serviceConnection, BIND_AUTO_CREATE);

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(serviceConnection);
    }
}