Android 背景动画

        项目要实现背景动画，就是背景图片比屏幕大，然后通过动画实现背景图片的上下左右循环移动，用到很多方法，下面是我认为效果最好的一种：

代码：

        public class Draw extends View implements Runnable{


private Bitmap bmp;
private int left = 0;
private int top = 0;
private Handler handler;
private int dx = 1;
private int dy = 1;
public static boolean isRunning = true;
private boolean mark=true;

public Draw(Context context) {
super(context);
// TODO Auto-generated constructor stub
}

public Draw(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
}

public Draw(Context context, AttributeSet attrs) {
super(context, attrs);
bmp = BitmapFactory.decodeResource(getResources(), R.drawable.homeback);
handler = new Handler();
new Thread(this).start();
// TODO Auto-generated constructor stub
}

@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
canvas.drawBitmap(bmp, left, top, null);
}

public void run() {
// TODO Auto-generated method stub
while (isRunning) {
if (left > (getWidth() - bmp.getWidth()+5) && mark) {
left = left - dx;
} else if (top > (getHeight() - bmp.getHeight()+5) && mark) {
top = top - dy;
if (top <= (getHeight() - bmp.getHeight()+5)){
mark = false;
}
} else if (left <= 0 && !mark) {
left = left + dx;
} else if (top <=0 && !mark) {
top = top + dy;
if (top >= 0)
mark = true;
}
handler.post(new Runnable() {

public void run() {
// TODO Auto-generated method stub
invalidate();
}
});
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

}

}

注释：通过子线程实现图片坐标的变化

在xml将自定义的View写上就可以了：

<com.microimage.view.Draw 
     android:layout_width="wrap_content"
      android:layout_height="wrap_content"/>