Android 碎屏效果 (Crack Screen,击碎屏幕)

实现思路：在一个透明的Activity上用一个自定义View，然后在View上画.9的碎玻璃图片，加上音效。然后过一段时间消失。

主要用一个postInvalidate();方法，用一个集合去装手指触摸过的地方，在touch事件中调用postInvalidate();方法进行视图重新绘制。

需要注意的是，这里的播放音效和上篇博客 Android 闪电效果 (Electric Screen,电动屏幕) 中的播放音效一样，暂停音效的时候要传开始播放时得到的int返回值，和停止音效不一样。

可以通过限制集合长度来限制绘制的屏幕个数。

单独开启一个线程，过一段时间开始清除效果， 即直接操作集合，操作完了调用postInvalidate(); 重新绘图就可以了。

示例代码：

public class CustomView extends View {  private Paint mPaint;  private SoundPool mSoundPool;  private Map<Integer, Integer> mSoundMap = new HashMap<Integer, Integer>();  private int mIndex;  private Bitmap mBitmap;  private ArrayList<Float> mXPointList;  private ArrayList<Float> mYPointList;  private int mCount = 0;// 点击次数  private int mLength = 30;// 绘制总数   public CustomView(Context context, AttributeSet attrs) {   super(context);   mPaint = new Paint();   mPaint.setAntiAlias(true);   mPaint.setColor(Color.BLUE);   // mPaint.setAlpha(127);   mPaint.setStrokeWidth(2.0f);   this.setKeepScreenOn(true);   this.setFocusable(true);   this.setLongClickable(true);   this.mSoundPool = new SoundPool(5, AudioManager.STREAM_SYSTEM, 5);   this.mSoundMap.put(1, mSoundPool.load(context, R.raw.cfokwowbfv, 1));   this.mBitmap = BitmapFactory.decodeResource(getResources(),     R.drawable.screen);   mXPointList = new ArrayList<Float>();   mYPointList = new ArrayList<Float>();   new Thread(new Runnable() {     @Override    public void run() {     // TODO Auto-generated method stub     while (true) {      try {       Thread.sleep(4000);      } catch (InterruptedException e) {       // TODO Auto-generated catch block       e.printStackTrace();      }      // mG++;      handler.sendEmptyMessage(0);     }     }   }).start();   }   @Override  public boolean onTouchEvent(MotionEvent arg1) {   // TODO Auto-generated method stub   switch (arg1.getAction()) {   case MotionEvent.ACTION_DOWN:    // drawBitmap(arg1.getX(), arg1.getY());    playSound();    mXPointList.add(arg1.getX());    mYPointList.add(arg1.getY());    postInvalidate();    mCount++;    if (mCount > mLength) {     mXPointList.remove(0);     mYPointList.remove(0);     mLength++;    }    break;   case MotionEvent.ACTION_UP:    break;   case MotionEvent.ACTION_MOVE:    break;   default:    break;   }   return super.onTouchEvent(arg1);  }   @Override  protected void onDraw(Canvas canvas) {   super.onDraw(canvas);   for (int i = 0; i < mXPointList.size(); ++i) {    canvas.drawBitmap(mBitmap, mXPointList.get(i) - mBitmap.getWidth()      / 2, mYPointList.get(i) - mBitmap.getHeight() / 2, null);   }  }   // 播放  public void playSound() {   mIndex = mSoundPool.play(mSoundMap.get(1), 1, 1, 0, 0, 1);  }   // 停止播放  public void stopSound() {   // Toast.makeText(getContext(), "zzzzz", 0).show();   mSoundPool.stop(mIndex);  }   @Override  public boolean onKeyDown(int keyCode, KeyEvent event) {   // TODO Auto-generated method stub   Toast.makeText(getContext(), "keydown", Toast.LENGTH_SHORT).show();   return super.onKeyDown(keyCode, event);  }   // 更新界面  Handler handler = new Handler() {   public void handleMessage(Message msg) {    if (msg.what == 0) {     if (mCount != 0 && mXPointList.size() != 0) {      for (int i = 0; i < new Random()        .nextInt(mXPointList.size() + 1); i++) {       mXPointList.remove(0);       mYPointList.remove(0);       mLength++;      }     }     postInvalidate();     }   }  }; } 

Github: https://github.com/OneHead/crack_screen2D

Weibo: https://weibo.com/2382477985