更改设备旋转时的iphone背景图像

Question

I have an UIImageView as a background behind my controls, the problem comes when rotating the device. I'd like to use a different image depending on the orientation .

So what would be the best way to handle that? Adding and removing each UIImageView for landscape and portrait? Having both on the view and hide/show the appropriate one? Or maybe there is some class or UIObject for handling that?

TIA

Answer 1

Now you can actually use size classes for this purpose. All you need to do is to set images for Any width compact height and do the hint given in this article: http://pinkstone.co.uk/how-to-handle-device-rotation-since-ios-8/ That's all you need for your background image to change on rotation.

Answer 2

You can just set its image property to a different image.

someUIImageView.image = [UIImage imageNamed:@"foo.png"];

Answer 3

You can get funky with it and have both background images overlaid, one with alpha = 1.0 and the other with alpha = 0.0. Then, when you rotation, use an animation to transition the alphas to 0.0 and 1.0, respectively to get a fade-in fade-out effect. If you choose this approach, I recommend putting the animation code in -viewWillAppear: For example, something like this:

[UIView beginAnimations:nil context:NULL]; {
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationDuration:1.0];
        [UIView setAnimationDelegate:self];
        if (toOrientation == UIInterfaceOrientationLandscape) {
                landscapeView.alpha = 1.0;
                portraitView.alpha = 0.0;
        }
        else {
                landscapeView.alpha = 0.0;
                portraitView.alpha = 1.0;
        }
} [UIView commitAnimations];