自定义View测量两指间距离和两指间中点

   
   两个小工具类


 //计算两指间距离
    private double spacing(MotionEvent event){
        float x = 0;
        float y = 0;
        x = event.getX(0) - event.getX(1);
        y = event.getY(0) - event.getY(1);
        return Math.sqrt(x*x + y*y);
    }
    //计算两指的中点
    private PointF mypoint(MotionEvent event){


        float x1 = event.getX(0);
        float x2 = event.getX(1);
        float y1 = event.getY(0);
        float y2 = event.getY(1);


        float x = (x1 + x2) / 2;
        float y = (y1 + y2) / 2;
        PointF pointF = new PointF(x, y);




        return pointF;
    }