iOS14.8下如何修改UIImagePickerController搜索栏的背景颜色

在iOS 14.8系统中调用系统UIImagePickerController时，控件自带的搜索栏默认背景为透明，会和后方视图内容重叠导致显示异常，可通过以下方案修复：

相关参考截图：

方案1：弹出UIImagePickerController时动态修改搜索栏背景 #

该方案不会影响全局其他搜索栏样式，适配性更高：

Objective-C 代码示例 #

UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
// 弹出后延迟遍历视图层级查找搜索栏
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
    [self findSearchBarInView:picker.view];
});
[self presentViewController:picker animated:YES completion:nil];

// 递归遍历视图查找UISearchBar
- (void)findSearchBarInView:(UIView *)view {
    for (UIView *subview in view.subviews) {
        if ([subview isKindOfClass:[UISearchBar class]]) {
            UISearchBar *searchBar = (UISearchBar *)subview;
            // 替换为你需要的背景色
            searchBar.backgroundColor = [UIColor whiteColor];
            // 可选：设置纯色背景图片彻底覆盖透明效果
            [searchBar setBackgroundImage:[UIImage new] forBarPosition:UIBarPositionAny barMetrics:UIBarMetricsDefault];
            return;
        }
        [self findSearchBarInView:subview];
    }
}

Swift 代码示例 #

let picker = UIImagePickerController()
picker.sourceType = .photoLibrary
present(picker, animated: true) {
    DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
        self.findSearchBar(in: picker.view)
    }
}

func findSearchBar(in view: UIView) {
    for subview in view.subviews {
        if let searchBar = subview as? UISearchBar {
            // 替换为你需要的背景色
            searchBar.backgroundColor = .white
            // 可选：设置纯色背景图片彻底覆盖透明效果
            searchBar.setBackgroundImage(UIImage(), for: .any, barMetrics: .default)
            return
        }
        findSearchBar(in: subview)
    }
}

方案2：全局修改UISearchBar外观 #

如果App内所有搜索栏需要统一背景样式，可直接通过外观协议设置，代码更简洁：

Objective-C 代码示例 #

[[UISearchBar appearance] setBackgroundColor:[UIColor whiteColor]];
[[UISearchBar appearance] setBackgroundImage:[UIImage new] forBarPosition:UIBarPositionAny barMetrics:UIBarMetricsDefault];

Swift 代码示例 #

UISearchBar.appearance().backgroundColor = .white
UISearchBar.appearance().setBackgroundImage(UIImage(), for: .any, barMetrics: .default)

注意：如果设置后仍存在透明效果，可额外修改搜索栏的searchTextField子视图的背景色，彻底覆盖系统默认透明属性。

内容的提问来源于stack exchange，提问作者Zas