UISearchBar--清除自带的背景

 1 - (void)removeSearchBarBackground
 2 {
 3     for (UIView *subView in self.subviews) {
 4         if (IsiOS7OrLater) {
 5             for (UIView *subSubView in subView.subviews) {
 6                 if ([subSubView isKindOfClass:NSClassFromString(@"UISearchBarBackground")]) {
 7                     [subSubView removeFromSuperview];
 8                 }
 9             }
10         } else if ([subView isKindOfClass:NSClassFromString(@"UISearchBarBackground")]) { // iOS6以下版本searchBar内部子视图的结构不一样
11             [subView removeFromSuperview];
12         }
13     }
14 }