iOS开发问题----UISearchBarController跳转导航栏闪烁问题

        在开发中又是某个页面需要是使用UISearchBarController 这个控件进行搜索，可能由其他界面跳转到搜索页面，而在跳转过程中可能会出现导航栏闪烁 的问题。UISearchBar闪烁，只要把barTintColor 设置为ClearColor就好了，代码如下

 - (void)removeSearchBarFrame:(UISearchBar *)searchBar
 {
     float version = [[[UIDevice currentDevice] systemVersion] floatValue];

     if ([searchBar respondsToSelector : @selector (barTintColor)]) {
         float  iosversion7_1 = 7.1 ;
         if (version >= iosversion7_1)
         {
             //iOS7.1

             [[[[searchBar.subviews objectAtIndex:0] subviews] objectAtIndex:0] removeFromSuperview];
             [searchBar setBackgroundColor:[UIColor clearColor]];
         }
         else
         {
             //iOS7.0
             [searchBar setBarTintColor:[UIColor clearColor]];
             [searchBar setBackgroundColor:[UIColor clearColor]];
         }
     }
     else
     {
         //iOS7.0 以下

         [[searchBar.subviews objectAtIndex:0] removeFromSuperview ];
         [searchBar setBackgroundColor :[ UIColor clearColor]];
     }
 }