更改UISearchBar系统背景色方法

1、

searchBar.searchBarStyle = UISearchBarStyleMinimal;

2、 

 searchBar.backgroundImage = [self imageWithColor:[UIColor clearColor]];

- (UIImage *)imageWithColor:(UIColor *)color

{

    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);

    UIGraphicsBeginImageContext(rect.size);

    CGContextRef context = UIGraphicsGetCurrentContext();

    

    CGContextSetFillColorWithColor(context, [color CGColor]);

    CGContextFillRect(context, rect);

    

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    

    return image;

}