Android碎屏效果

转自：顾明伟 http://blog.csdn.net/u013045971
本文介绍一个好玩的App 如图：



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：

[java] view
plain copy

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