如何将HEX RGB颜色代码转换为UIColor？

Question

我有一个RGB十六进制代码，如#ffffff作为NSString，并希望将其转换为UIColor。有没有一种简单的方法可以做到这一点？

Answer 1

In some code of mine，我使用了两种不同的功能：

void SKScanHexColor(NSString * hexString, float * red, float * green, float * blue, float * alpha) {
  NSString *cleanString = [hexString stringByReplacingOccurrencesOfString:@"#" withString:@""];
  if([cleanString length] == 3) {
      cleanString = [NSString stringWithFormat:@"%@%@%@%@%@%@", 
                     [cleanString substringWithRange:NSMakeRange(0, 1)],[cleanString substringWithRange:NSMakeRange(0, 1)],
                     [cleanString substringWithRange:NSMakeRange(1, 1)],[cleanString substringWithRange:NSMakeRange(1, 1)],
                     [cleanString substringWithRange:NSMakeRange(2, 1)],[cleanString substringWithRange:NSMakeRange(2, 1)]];
  }
  if([cleanString length] == 6) {
      cleanString = [cleanString stringByAppendingString:@"ff"];
  }

  unsigned int baseValue;
  [[NSScanner scannerWithString:cleanString] scanHexInt:&baseValue];

  if (red) { *red = ((baseValue >> 24) & 0xFF)/255.0f; }
  if (green) { *green = ((baseValue >> 16) & 0xFF)/255.0f; }
  if (blue) { *blue = ((baseValue >> 8) & 0xFF)/255.0f; }
  if (alpha) { *alpha = ((baseValue >> 0) & 0xFF)/255.0f; }
}

然后我就这样使用它：

UIColor * SKColorFromHexString(NSString * hexString) {
  float red, green, blue, alpha;
  SKScanHexColor(hexString, &red, &green, &blue, &alpha);

  return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
}

如果您希望将其用作UIColor类别，则只需更改几行：

+ (UIColor *) colorFromHexString:(NSString *)hexString {
  NSString *cleanString = [hexString stringByReplacingOccurrencesOfString:@"#" withString:@""];
  if([cleanString length] == 3) {
      cleanString = [NSString stringWithFormat:@"%@%@%@%@%@%@", 
                     [cleanString substringWithRange:NSMakeRange(0, 1)],[cleanString substringWithRange:NSMakeRange(0, 1)],
                     [cleanString substringWithRange:NSMakeRange(1, 1)],[cleanString substringWithRange:NSMakeRange(1, 1)],
                     [cleanString substringWithRange:NSMakeRange(2, 1)],[cleanString substringWithRange:NSMakeRange(2, 1)]];
  }
  if([cleanString length] == 6) {
      cleanString = [cleanString stringByAppendingString:@"ff"];
  }

  unsigned int baseValue;
  [[NSScanner scannerWithString:cleanString] scanHexInt:&baseValue];

  float red = ((baseValue >> 24) & 0xFF)/255.0f;
  float green = ((baseValue >> 16) & 0xFF)/255.0f;
  float blue = ((baseValue >> 8) & 0xFF)/255.0f;
  float alpha = ((baseValue >> 0) & 0xFF)/255.0f;

  return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
}

这将处理“＃abc”，“＃abcdef31”等字符串

Answer 2

如果您使用十六进制值..

#define UIColorFromRGB(rgbValue) [UIColor \
       colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
       green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
       blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]

  //Then use any Hex value

 self.view.backgroundColor = UIColorFromRGB(0xD2691E);   

Answer 3

我一直在寻找一个简单的解决方案，并想出了这个（不完全是Objective-C，但就像魅力一样）：

NSString *stringColor = @"#AABBCC";
NSUInteger red, green, blue;
sscanf([stringColor UTF8String], "#%02X%02X%02X", &red, &green, &blue);

UIColor *color = [UIColor colorWithRed:red/255.0 green:green/255.0 blue:blue/255.0 alpha:1];

Answer 4

UIColor有一个很好的类别叫"UIColor+Expanded"，它有一个类方法，用于从RGB十六进制字符串中获取UIColor：

使用简单：

UIColor *myColor = [UIColor colorWithHexString:@"FF0000"];

另外，它为UIColor添加了许多其他可能有用的实用程序。有关详细信息，请参阅this article。

Answer 5

简单，只需访问此网站并输入您的十六进制值：http://www.corecoding.com/utilities/rgb-or-hex-to-float.php

Answer 6

+ (UIColor *)colorWithHexString:(NSString *)colorString
{
    colorString = [colorString stringByReplacingOccurrencesOfString:@"#" withString:@""];

    if (colorString.length == 3)
        colorString = [NSString stringWithFormat:@"%c%c%c%c%c%c",
        [colorString characterAtIndex:0], [colorString characterAtIndex:0],
        [colorString characterAtIndex:1], [colorString characterAtIndex:1],
        [colorString characterAtIndex:2], [colorString characterAtIndex:2]];

    if (colorString.length == 6)
    {
        int r, g, b;
        sscanf([colorString UTF8String], "%2x%2x%2x", &r, &g, &b);
        return [UIColor colorWithRed:(r/255.0) green:(g/255.0) blue:(b/255.0) alpha:1.0];
    }
    return nil;
}

格式＃123,123，＃fff195，fff195

+ (UIColor *)colorWithHexValue:(int)hexValue
{
    float red   = ((hexValue & 0xFF0000) >> 16)/255.0;
    float green = ((hexValue & 0xFF00) >> 8)/255.0;
    float blue  = (hexValue & 0xFF)/255.0;
    return [UIColor colorWithRed:red green:green blue:blue alpha:1.0];
}

格式为0xfff195

Answer 7

我找到的最简单方法：Hex to UIColor Converter

只需输入不带“＃”的十六进制数字，它就会返回UIColor代码。例如，橙色（＃f77f00）的代码是：

[UIColor colorWithRed:0.969 green:0.498 blue:0 alpha:1.0]

Answer 8

我想我将六个字符分成三对，然后将其转换为十进制，然后将其除以255，以使每个颜色分量成为浮点数。

然后，您可以将组件传递给：

[UIColor colorWithRed: green: blue: alpha:1];

Answer 9

我创建了一个在线工具，可以立即将任何十六进制代码转换为Swift和Objective-C的UIColor代码段，以便在使用自定义方法或插件时不方便：https://iosref.com/uihex/

Answer 10

如果您不想编写上述所有代码，可以查看以下网站：http://www.diovo.com/apps/rgb-to-uicolor-converter.html
从像这样的HEX颜色：#FFFFFF，网站将其转换为如下字符串：

UIColor *aColor = [UIColor colorWithRed:1 green:1 blue:1 alpha:1.000];

Answer 11

如果从ObjectiveC转换为swift对你来说很难，那么这就是Swift的答案。目前它只需要没有＃的字符串，但你可以添加一个扫描方法来跳过它我相信。

func stringToColor(stringColor: String) -> UIColor {
    var hexInt: UInt32 = 0
    let scanner = NSScanner(string: stringColor)
    scanner.scanHexInt(&hexInt)
    let color = UIColor(
        red: CGFloat((hexInt & 0xFF0000) >> 16)/255,
        green: CGFloat((hexInt & 0xFF00) >> 8)/255,
        blue: CGFloat((hexInt & 0xFF))/255,
        alpha: 1)

    return color
}

Answer 12

不要忘记您可以选择convert your hex values to RGB并在界面构建器中输入它们。它会保存一些代码行。

Answer 13

猜猜这里有点晚了......但我在WhiteHouse Github回购中找到了这个版本，以一种非常优雅的方式做到了：

+(UIColor *)colorFromRGBHexString:(NSString *)colorString {
    if(colorString.length == 7) {
        const char *colorUTF8String = [colorString UTF8String];
        int r, g, b;
        sscanf(colorUTF8String, "#%2x%2x%2x", &r, &g, &b);
        return [UIColor colorWithRed:(r / 255.0) green:(g / 255.0) blue:(b / 255.0) alpha:1.0];
    }    
    return nil;
}

Source Link to their WHAppConfig.m on github

Answer 14

我最终为UIColor创建了一个类别，我可以在其他项目中重复使用。

<强>目标C

#import <UIKit/UIKit.h>

@interface UIColor (HexColor)

+ (UIColor *)colorFromHex:(unsigned long)hex;

@end

@implementation UIColor (HexColor)

+ (UIColor *)colorFromHex:(unsigned long)hex
{
  return [UIColor colorWithRed:((float)((hex & 0xFF0000) >> 16))/255.0 green:((float)((hex & 0xFF00) >> 8))/255.0 blue:((float)(hex & 0xFF))/255.0 alpha:1.0];
}

@end

// USAGE
UIColor *customRedColor = [UIColor colorFromHex:0x990000];

<强>夫特

extension UIColor {

  convenience init(hex: Int) {
    let red = CGFloat((hex & 0xff0000) >> 16) / 255.0
    let green = CGFloat((hex & 0x00ff00) >> 8) / 255.0
    let blue = CGFloat(hex & 0x0000ff) / 255.0
    self.init(red: red, green: green, blue: blue, alpha: 1.0)
  }

}

// USAGE
let customColor = UIColor(hex: 0x990000)

Answer 15

我认为使用HEX值时有一种更简单的方法。 只需在文件顶部添加一个定义，或引用转换的头文件（UIColorFromRGB）。您甚至可以添加固定HEX颜色值的模板。

#define CLR_YELLOW_TEXT     0xf4dc89    // A Light Yellow text
#define CLR_GREEN_TEXT      0x008040    // Dark Green text for my buttons

#define UIColorFromRGB(rgbValue)  [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 green:((float)((rgbValue & 0xFF00) >> 8))/255.0 blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]

然后直接使用HEX值或您定义的十六进制值在代码中引用它。 例如......

[myButton1 setTitleColor:UIColorFromRGB(0xd02d2d) forState:UIControlStateNormal];
[myButton2 setTitleColor:UIColorFromRGB(CLR_GREEN_TEXT) forState:UIControlStateNormal];
[myButton3 setTitleColor:UIColorFromRGB(CLR_YELLOW_TEXT) forState:UIControlStateNormal];

（PS - 假定Alpha为1.0，但在定义中总是可以更改。）

享受。

Answer 16

我发现一个cocoapod库在使用“#RRGGBB”值创建UIColor时非常有用。

pod 'UIColor-HexRGB'

Answer 17

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

{

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

if ([cString length] < 6) return [UIColor grayColor];

if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];

if ([cString length] != 6) return  [UIColor grayColor];

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];

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];

}