16進制顏色轉換

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

{

    NSString *cString = [[color stringByTrimmingCharactersInSet:[NSCharacterSetwhitespaceAndNewlineCharacterSet]] 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;

    [[NSScannerscannerWithString:rString] scanHexInt:&r];

    [[NSScannerscannerWithString:gString] scanHexInt:&g];

    [[NSScannerscannerWithString:bString] scanHexInt:&b];

    

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

}