自定义iOS搜索框

 替换搜索的背景图，

for (UIView *subview in self.searchBar.subviews)

    {
        if ([subview isKindOfClass:NSClassFromString(@"UISearchBarBackground")])  
        {    
           ((UIImageView*)subview).image=[UIImage imageNamed:@"searchBg.png"];//替换了搜索框的背景图片
        }

        if ([subview isKindOfClass:[UITextField class]])

        {

            UITextField *textField = (UITextField *)subview;

            textField.borderStyle = UITextBorderStyleRoundedRect;//将搜索框的边框变成了矩形

            break;

          }
    }