UISearchBar 闪现背景色解决方案

说明

此处记录项目中的一个bug解决方案, 希望可以帮助遇到相同问题的小伙伴. UISearchBar 放在导航栏, 当pop控制器时, searchBar会闪现背景色.

bug 演示

searchBar 闪现背景色bug演示.gif

寻找bug

UISearchbar 随着iOS的版本升级也在不断的发生着变化我们可以使用UIView的recursiveDescription方法查看searchBar的视图层次结构, 断点调试: po [××× recursiveDescription] 此处测试版本: 模拟器 iOS10.2(14C89)

调试结果

(lldb) po [searchBar recursiveDescription]
<DopSearchBar: 0x7fd36ed89850; baseClass = UISearchBar; frame = (0 0; 0 0); text = ''; tintColor = UIExtendedGrayColorSpace 0 0; gestureRecognizers = <NSArray: 0x6080004551b0>; layer = <CALayer: 0x60800063b7a0>>
   | <UIView: 0x7fd36efb1b90; frame = (0 0; 0 0); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x608000639cc0>>
   |    | <UISearchBarBackground: 0x7fd36ee2fce0; frame = (0 0; 0 0); userInteractionEnabled = NO; layer = <CALayer: 0x60000042e040>> - (null)
   |    | <UISearchBarTextField: 0x7fd36ed8e950; frame = (0 0; 0 0); text = ''; opaque = NO; tintColor = UIExtendedSRGBColorSpace 0.215686 0.709804 0.988235 1; layer = <CALayer: 0x60000042bec0>>
   |    |    | <UITextFieldBorderView: 0x7fd36ec48520; frame = (0 0; 0 0); clipsToBounds = YES; opaque = NO; layer = <CALayer: 0x60000042e1e0>>

ps: DopSearchBar 是子类化的searchBar

searchBar 层级结构如下图 searchBar 层次结构.png

修复bug

我们只需要移除 UISearchBarBackground即可

代码如下, 代码中的self为子类化的searchBar

for (UIView *subV in self.subviews) {
        if (subV.subviews.count > 0 && [subV.subviews.firstObject isKindOfClass:NSClassFromString(@"UISearchBarBackground")]) {
            [subV.subviews.firstObject removeFromSuperview];
            break;
        }
    }

修复bug后的效果

fix bug.gif

参考文章

UISearchbar去除背景色的方法，适合iOS5/6/7/8.0beta