如何在控制器内部使用IBAction在自定义视图中绘制圆圈？

I draged out a generic view and hooked it up to my circleView.m. I then dragged out a round rect button on top of that view and hooked up an IBAction to it. As of right now, when the view loads the circle is automatically drawn onto the screen. What I would like to do is draw the circle on the screen only when the button is pressed using drawRect or some other draw method. Here is my code:I draged out a generic view and hooked it up to