Question

问题出在标题中，如何从Plist设置UILabel的UIColor？

我试过这个：

UIColor *colorLabel;

我在我的Plist中添加一个NSString行，并将redColor写为值，但不起作用......

我该如何处理？

谢谢你们。

Answer 1

我认为你需要从字符串转换为UIColor。你用十六色（红色 - ff0000）将颜色放入你的plist中，然后使用类似下面的函数来获取UIColor。

+ (UIColor *) colorWithHexString: (NSString *) stringToConvert
{
    NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    // String should be 6 or 8 characters
    if ([cString length] < 6) return [UIColor blackColor];
    // strip 0X if it appears
    if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];
    if ([cString length] != 6) return [UIColor blackColor];
    // Separate into r, g, b substrings
    NSRange range;
    range.location = 0;
    range.length = 2;
    NSString *rString = [cString substringWithRange:range];
    range.location = 2;
    NSString *gString = [cString substringWithRange:range];
    range.location = 4;
    NSString *bString = [cString substringWithRange:range];
    // Scan values
    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];
}

Answer 2

我个人会存储RGBA值而不是字符串然后你可以使用

 + (UIColor *)colorWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha

请勿执行以下操作

正如一个有趣的旁注，最不灵活的方式是使用像这样的UIColor便利方法

[UIColor performSelector:NSSelectorFromString(@"redColor")]

Answer 3

为了保持人类的可读性，我为此做了一个类别：

@implementation UIColor (EPPZRepresenter)


NSString *NSStringFromUIColor(UIColor *color)
{
    const CGFloat *components = CGColorGetComponents(color.CGColor);
    return [NSString stringWithFormat:@"[%f, %f, %f, %f]",
            components[0],
            components[1],
            components[2],
            components[3]];
}

UIColor *UIColorFromNSString(NSString *string)
{
    NSString *componentsString = [[string stringByReplacingOccurrencesOfString:@"[" withString:@""] stringByReplacingOccurrencesOfString:@"]" withString:@""];
    NSArray *components = [componentsString componentsSeparatedByString:@", "];
    return [UIColor colorWithRed:[(NSString*)components[0] floatValue]
                           green:[(NSString*)components[1] floatValue]
                            blue:[(NSString*)components[2] floatValue]
                           alpha:[(NSString*)components[3] floatValue]];
}


@end

NSStringFromCGAffineTransform使用的格式相同。这实际上是eppz!kit at GitHub中更大规模的plist对象代表的一部分。

如何从Plist设置UILabel的UIColor

3 个答案: