处理表面中的多点触控

public class CustomSurfaceView extends SurfaceView {
    @Override
    public boolean onTouchEvent(MotionEvent e) {
        super.onTouchEvent(e);
        if(e.getPointerCount() > 2){
            return false; // If we want to limit the amount of pointers, we return false
                // which disallows the pointer. It will not be reacted on either, for
                // any future touch events until it has been lifted and repressed.
        }

        // What can you do here? Check if the amount of pointers are [x] and take action,
        // if a pointer leaves, a new enters, or the [x] pointers are moved.
        // Some examples as to handling etc. touch/motion events.

        switch (MotionEventCompat.getActionMasked(e)) {
            case MotionEvent.ACTION_DOWN:
            case MotionEvent.ACTION_POINTER_DOWN:
                // One or more pointers touch the screen.
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_POINTER_UP:
                // One or more pointers stop touching the screen.
                break;
            case MotionEvent.ACTION_MOVE:
                // One or more pointers move.
                if(e.getPointerCount() == 2){
                    move();
                }else if(e.getPointerCount() == 1){
                    paint();
                }else{
                    zoom();
                }
                break;
        }
        return true; // Allow repeated action.    
    }
}