for循环不会“增长”圆圈。我需要“成长”一个圆圈

I am trying to write an android application that draws Circles at random positions over and over forever. This is already done in my code. The next objective for me is to slowly animate these circles to make them "grow" onto the screen. Basically increment the radius of the circle from 0 to 300 very fast I did this by creating a for loop like this.I am trying to write an android application tha