<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"tools:context=".MainActivity"><ImageViewandroid:src="@drawable/after1"android:layout_width="wrap_content"android:layout_height="wrap_content" /><ImageViewandroid:id="@+id/iv2android:layout_width="wrap_content"android:layout_height="wrap_content" />
</RelativeLayout>

然后我们看java代码：

       bitmap= BitmapFactory.decodeResource(getResources(), R.drawable.pre1);

在对B图进行处理之前我们先得出B图的副本copyBitmap：

copyBitmap=Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());

   Canvas canvas=new Canvas(copyBitmap);

3.new一支画笔出来,并设置默认颜色：

        Paint paint=new Paint();paint.setColor(Color.BLACK);

4.最后照着B图“画”出来

 canvas.drawBitmap(bitmap, new Matrix(), paint);

就这样copyBitmap就与B图的实例bitmap一模一样了，也就是说已经创建出B图的的副本啦。

 iv2.setImageBitmap(bitmap);

现在运行会看到是这个样子的：

        iv2.setOnTouchListener(new View.OnTouchListener() {@Overridepublic boolean onTouch(View v, MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_MOVE:int x = (int) event.getX();int y = (int) event.getY();copyBitmap.setPixel(x, y , Color.TRANSPARENT);iv2.setImageBitmap(copyBitmap);Log.i("test", x + "," + y);break;}return true;}});

copyBitmap.setPixel(x, y , Color.TRANSPARENT);代码就是将坐标为想x,y的像素点设置为透明色，而event.getX（）与event.getY（）则是分别获取用户触摸控件上的x坐标和y坐标。请注意这里笔者说的是控件上的坐标，并不是屏幕上的坐标。关于屏幕坐标与控件坐标的区别可以看以下博文

 case MotionEvent.ACTION_MOVE:int x = (int) event.getX();int y = (int) event.getY();for (int i = -18; i < 20; i++) {for (int j = -18; j < 20; j++) {try {copyBitmap.setPixel(x + i, y + j, Color.TRANSPARENT);} catch (Exception e) {// TODO: handle exception}}}iv2.setImageBitmap(copyBitmap);Log.i("test", x + "," + y);break;

        iv2.setOnTouchListener(new View.OnTouchListener() {@Overridepublic boolean onTouch(View v, MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_UP:mediaPlayer = MediaPlayer.create(getApplicationContext(), R.raw.higirl);mediaPlayer.start();;break;case MotionEvent.ACTION_MOVE:int x = (int) event.getX();int y = (int) event.getY();for (int i = -18; i < 20; i++) {for (int j = -18; j < 20; j++) {try {copyBitmap.setPixel(x + i, y + j, Color.TRANSPARENT);} catch (Exception e) {// TODO: handle exception}}}iv2.setImageBitmap(copyBitmap);Log.i("test", x + "," + y);break;case MotionEvent.ACTION_DOWN:if(mediaPlayer!=null){mediaPlayer.stop();mediaPlayer.release();}break;}return true;}

声音文件笔者放到res\raw里面了。