动态位图

public class BitmapMovie extends Activity{
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		
		this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(new BitmapMovieView(this));
	}
}
	

class BitmapMovieView extends SurfaceView implements Callback,Runnable{
	private SurfaceHolder mSurfaceHolder;
	private Paint mPaint;
	private Canvas mCanvas;
	private Thread mThread;
	private Bitmap mBitmap;
	private int mBmpX;
	private int mBmpY;
	private boolean mFlag;
	

	public BitmapMovieView(Context context) {
		super(context);
		mSurfaceHolder=this.getHolder();
		mSurfaceHolder.addCallback(this);
		mPaint=new Paint();
		mPaint.setColor(Color.WHITE);
		mPaint.setAntiAlias(true);
		setFocusable(true);
	}

	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width,
			int height) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		mBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.water);
		mBmpX=-mBitmap.getWidth()+this.getWidth();
		mBmpY=this.getHeight()-mBitmap.getHeight();
		
		mFlag=true;
		mThread=new Thread(this,"My Draw");
		mThread.start();  
	}

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {
		mFlag=false;
	}

	@Override
	public void run() {
		while (mFlag) {
			long start=System.currentTimeMillis();
			myDraw();
			logic();
			long end=System.currentTimeMillis();
			if ((end-start)<50) {
				try {
					Thread.sleep(50-(end-start));
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}
	
	private void myDraw() {
		try {
			mCanvas=mSurfaceHolder.lockCanvas();
			if (mCanvas != null) {
				mCanvas.drawColor(Color.WHITE);
				mCanvas.drawBitmap(mBitmap, mBmpX, mBmpY, new Paint());
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if (mCanvas != null) {
				mSurfaceHolder.unlockCanvasAndPost(mCanvas);
			}
		}
	}
	
	private void logic() {
		mBmpX+=5;
	}
	
	
}

这会产生动态水波的效果，其实这种效果是在不断的将这个图片右移不同的重新画上去的，而不是真的水波效果。

mBmpX=-mBitmap.getWidth()+this.getWidth();

-1068=-1388+320;

算出来图片的x坐标是-1068，在画图的时候虽然不在屏幕上但是是可以的，相当于是在相对于屏幕左上角为圆点的坐标系中，这个的坐标是负的。