android如何使用动画处理线程

Question

我怎样才能throw any object(Stone) continuously到moving Horizontally object？我使用了一个线程，它可以连续使用翻译动画来扔石头，但是内存使用量很大，我的设备在3-4 min.How之后就会慢下来来解决dis问题？

Answer 1

我认为您最好实现自己的SurfaceView。在它中，您可以更巧妙地绘制动画对象(使用专用线程)，而不是使用视图动画。(当然，您必须为此重写部分代码，但从长远来看，这可能是最好的)。

如果您想尝试SurfaceView，我建议您查看一下来自安卓的月球着陆器示例。

示例：

public class ThrowView extends SurfaceView implements SurfaceHolder.Callback, OnGestureListener{
    //The OnGestureListener can detect a fling motion.
    private class DrawingThread extends Thread{
        private final float timefactor = 0.0001f; //This is used to make the animation a bit slower. Play with this value if the animation seems too be to slow or too fast.
        private final float damp = 0.9; //This is used to slow down the object. If it stops too fast or slow, this is the value to change.
        private float stoneX = 0; //The x-coordinate of our stone object. Use this when drawing.
        private float stoneY = 0; //The y-coordinate of our stone object. Use this when drawing.
        @Override
        public void run(){
            while(running){
            Canvas c = null;
            try{
                c = surfaceHolder.lockCanvas(null);
                synchronized (surfaceHolder) { 
                    updatePhysics();
                    doDraw(c); //doDraw is not in this example, but it should essentially just draw our object at stoneX, stoneY.
                }
            }finally{
                if(c!=null) surfaceHolder.unlockCanvasAndPost(c); 
            }
            SystemClock.sleep(40);
        }
        private void updatePhysics(long time){
            //Calculate how much time has passed since last step:
            time1 = System.currentTimeMillis();
            dT = (time1 - time2)*timefactor;
            time2 = time1;

            //Move the stone in x depending on the time and velocity:
            stoneX += vX*dT;
            //Decrease the velocity:
            vX -= dT*damp:
        }
    }
    protected volatile float vX = 0; //This is the x-speed. To be able to throw in y too, just make another variable for that.
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        //This is our onFling, here we take the velocity of the users fling and set our variable to that.
        //Note that this value is based on pixels.
        vX = velocityX;
        return true;
    }
    @Override
    public boolean onDown(MotionEvent e) {
        //The onDown should return true so onFling can be activated:
        return true;
    }
}

为便于使用，根据月球着陆器样本制作了此示例。这里省略了许多方法(对于这个例子来说不是必需的)，但是可以根据月球着陆器来实现。