iOS-(修改导航栏的颜色)-----色值转化为图片

+(UIImage *)buttonImageFromColor:(UIColor *)color{

    CGRect rect = CGRectMake(0, 0, 2, 2);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext(); return img;
}