修改NavigationBar的分根线颜色

[self.navigationController.navigationBar setShadowImage:[Static ColorToImage:[Static colorWithHexString:[UIColor red]]]];

Static 里的几个静态方法

+ (UIImage *)ColorToImage:(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 *theImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return theImage;

}

+ (UIColor *) colorWithHexString: (NSString *)color{

    NSString *cString = [[color stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];

    if ([cString length] < 6) {

        return [UIColor clearColor];

    }

    if ([cString hasPrefix:@"0X"])

        cString = [cString substringFromIndex:2];

    if ([cString hasPrefix:@"#"])

        cString = [cString substringFromIndex:1];

    if ([cString length] != 6)

        return [UIColor clearColor];

    // 拆分

    NSRange range;

    range.location = 0;

    range.length = 2;

    //R

    NSString *rString = [cString substringWithRange:range];

    //G

    range.location = 2;

    NSString *gString = [cString substringWithRange:range];

    //B

    range.location = 4;

    NSString *bString = [cString substringWithRange:range];

    //Scan

    unsigned int r, g, b;

    [[NSScanner scannerWithString:rString] scanHexInt:&r];

    [[NSScanner scannerWithString:gString] scanHexInt:&g];

    [[NSScanner scannerWithString:bString] scanHexInt:&b];

    return [UIColor colorWithRed:((float) r / 255.0f) green:((float) g / 255.0f) blue:((float) b / 255.0f) alpha:1.0f];

}