put subviews of a UIView in front of its CALayer?

问题

Is this possible? Basically, I want to give my UIView a subview, and have that subview be in front of the view's layer (more specifically, in front of said layer's border).

Of course I could achieve the effect I want by making two subviews of the view's superview, one on top of the other. But I'd rather avoid that if possible.

回答1:

I looked for this for a while myself; i don't believe it is possible. I solved the issue by, as you hint at, adding the subview and the parent to the same 'container' superview. Then its just a matter of ordering the two subviews, so that your subview is above the other and its border.

回答2:

I solved this with a segue animation where i needed the sourceViewController to be in front of the destinationViewController. I had to remove the sourceViewController in order to re-nest it. My code looks like this:

- (void) perform {

    UIViewController *sourceViewController = (UIViewController *) self.sourceViewController;
    UIViewController *destinationViewController = (UIViewController *) self.destinationViewController;
    UIView *parent = sourceViewController.view.superview;
    [sourceViewController.view removeFromSuperview];
    [parent addSubview: destinationViewController.view];
    [parent addSubview:sourceViewController.view];

    // Perform animation stuffs...

}

来源：https://stackoverflow.com/questions/6551394/put-subviews-of-a-uiview-in-front-of-its-calayer