UIImagePickerController的delegate类中实现UINavigationControllerDelegate代理中的方法：
-(void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated;
Swift
func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
if #available(iOS 11, *) {
if viewController.isKind(of: NSClassFromString("PUPhotoPickerHostViewController")!) {
for view: UIView in viewController.view.subviews {
if view.frame.size.width < 42 {
viewController.view.sendSubviewToBack(view)
}
}
}
}else{
return
}
}
Objective-C
-(void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated{
if ([UIDevice currentDevice].systemVersion.floatValue < 11) {
return;
}
if ([viewController isKindOfClass:NSClassFromString(@"PUPhotoPickerHostViewController")]) {
[viewController.view.subviews enumerateObjectsUsingBlock:^(__kindof UIView * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
// iOS 11之后，图片编辑界面最上层会出现一个宽度<42的view，会遮盖住左下方的cancel按钮，使cancel按钮很难被点击到，故改变该view的层级结构
if (obj.frame.size.width < 42) {
[viewController.view sendSubviewToBack:obj];
*stop = YES;
}
}];
}
}
