android studio onTouch触摸事件

case MotionEvent.ACTION_MOVE:
float lastdis=-1;
//                System.out.println("move");
//                System.out.println(String.format("x:%f,y:%f",event.getX(),event.getY()));
//移动图片
FrameLayout.LayoutParams fl=(FrameLayout.LayoutParams)imageView.getLayoutParams();
fl.leftMargin=(int)event.getX();
fl.topMargin=(int)event.getY();
imageView.setLayoutParams(fl);
//放大缩小图片
if (event.getPointerCount()>=2){

float xd=event.getX(0)-event.getY(1);
float yd=event.getY(0)-event.getY(1);
float curdis= (float) Math.sqrt(xd*xd+yd*yd);
if (lastdis<0){
lastdis=curdis;
}else {
if ((curdis-lastdis)>5){
System.out.println("lager");
FrameLayout.LayoutParams fl=(FrameLayout.LayoutParams)imageView.getLayoutParams();
fl.width=(int)(1.1f*imageView.getWidth());
fl.height=(int)(1.1f*imageView.getHeight());
imageView.setLayoutParams(fl);
lastdis=curdis;
}else {
if ((lastdis-curdis)>5){
System.out.println("smaller");
FrameLayout.LayoutParams fl=(FrameLayout.LayoutParams)imageView.getLayoutParams();
fl.width=(int)(0.9f*imageView.getWidth());
fl.height=(int)(0.9f*imageView.getHeight());
imageView.setLayoutParams(fl);
lastdis=curdis;
}
}
}
}

break;