如何将Moda视图的背景设置为半透明？

Question

I call my ModalViewController by tapping into a Button. I want this ModalViewController have a Translucent background like below:

when i use [self.view setBackgroundColor:[UIColor clearColor]]; it gives me a black background:

Answer 1

    [modalView.view setBackgroundColor:[UIColor clearColor]];

或者如果您想降低不透明度

 [modalView.view setalpha:0.4]; //range is from 0(transparent) to 1(opaque)