拖拽功能：让图片在屏幕上任意移动

public class DragExampleActivity extends Activity { Bitmap mBitmap; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.icon); setContentView(new DragView(this)); } @Override protected void onDestroy() { super.onDestroy(); if(null != mBitmap) { mBitmap.recycle(); mBitmap = null; } } private class DragView extends View { private int mMotionX = 0; private int mMotionY = 0; private Paint paint; public DragView(Context context) { super(context); paint = new Paint(); } @Override public void draw(Canvas canvas) { super.draw(canvas); canvas.drawBitmap(mBitmap, mMotionX, mMotionY, paint); } @Override public boolean onTouchEvent(MotionEvent ev) { if(ev.getAction() == MotionEvent.ACTION_DOWN) { mMotionX = (int) ev.getX(); mMotionY = (int) ev.getY(); invalidate(); return true; }else { return super.onTouchEvent(ev); } } }}