Swift 5, iOS 14

convenience init(hex: String, alpha: CGFloat = 1.0) {
    var hexFormatted: String = hex.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines).uppercased()
    
    if hexFormatted.hasPrefix("#") {
        hexFormatted = String(hexFormatted.dropFirst())
    }
    
    assert(hexFormatted.count == 6, "Invalid hex code used.")
    
    var rgbValue: UInt64 = 0
    Scanner(string: hexFormatted).scanHexInt64(&rgbValue)
    
    self.init(red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
              green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
              blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
              alpha: alpha)
}

您可以使用各种在线工具将HEX字符串转换为实际的UIColor。查看uicolor.org或UI颜色选择器。输出将被转换为Objective-C代码，如下所示:

[UIColor colorWithRed:0.93 green:0.80 blue:0.80 alpha:1.0];

可以嵌入到应用程序中。希望这能有所帮助!

 You Can Get UIColor From String Code Like
   circularSpinner.fillColor = [self getUIColorObjectFromHexString:@"27b8c8" alpha:9];

 //Function For Hex Color Use
    - (unsigned int)intFromHexString:(NSString *)hexStr
    {
        unsigned int hexInt = 0;

        // Create scanner
        NSScanner *scanner = [NSScanner scannerWithString:hexStr];

        // Tell scanner to skip the # character
        [scanner setCharactersToBeSkipped:[NSCharacterSet characterSetWithCharactersInString:@"#"]];

        // Scan hex value
        [scanner scanHexInt:&hexInt];

        return hexInt;
    }




    - (UIColor *)getUIColorObjectFromHexString:(NSString *)hexStr alpha:(CGFloat)alpha
    {
        // Convert hex string to an integer
        unsigned int hexint = [self intFromHexString:hexStr];

        // Create color object, specifying alpha as well
        UIColor *color =
        [UIColor colorWithRed:((CGFloat) ((hexint & 0xFF0000) >> 16))/255
                        green:((CGFloat) ((hexint & 0xFF00) >> 8))/255
                         blue:((CGFloat) (hexint & 0xFF))/255
                        alpha:alpha];

        return color;
    }

    /Function For Hex Color Use
    - (unsigned int)intFromHexString:(NSString *)hexStr
    {
        unsigned int hexInt = 0;

        // Create scanner
        NSScanner *scanner = [NSScanner scannerWithString:hexStr];

        // Tell scanner to skip the # character
        [scanner setCharactersToBeSkipped:[NSCharacterSet characterSetWithCharactersInString:@"#"]];

        // Scan hex value
        [scanner scanHexInt:&hexInt];

        return hexInt;
    }




    - (UIColor *)getUIColorObjectFromHexString:(NSString *)hexStr alpha:(CGFloat)alpha
    {
        // Convert hex string to an integer
        unsigned int hexint = [self intFromHexString:hexStr];

        // Create color object, specifying alpha as well
        UIColor *color =
        [UIColor colorWithRed:((CGFloat) ((hexint & 0xFF0000) >> 16))/255
                        green:((CGFloat) ((hexint & 0xFF00) >> 8))/255
                         blue:((CGFloat) (hexint & 0xFF))/255
                        alpha:alpha];

        return color;
    }

使用这个类别:

在文件UIColor+Hexadecimal.h中

#import <UIKit/UIKit.h>

@interface UIColor(Hexadecimal)

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

@end

在文件UIColor+Hexadecimal.m中

#import "UIColor+Hexadecimal.h"

@implementation UIColor(Hexadecimal)

+ (UIColor *)colorWithHexString:(NSString *)hexString {
    unsigned rgbValue = 0;
    NSScanner *scanner = [NSScanner scannerWithString:hexString];
    [scanner setScanLocation:1]; // bypass '#' character
    [scanner scanHexInt:&rgbValue];

    return [UIColor colorWithRed:((rgbValue & 0xFF0000) >> 16)/255.0 green:((rgbValue & 0xFF00) >> 8)/255.0 blue:(rgbValue & 0xFF)/255.0 alpha:1.0];
}

@end

你想在课堂上使用它:

#import "UIColor+Hexadecimal.h"

and:

[UIColor colorWithHexString:@"#6e4b4b"];

你可以创建UIColor的扩展类:-

扩展UIColor {

// MARK: - getColorFromHex ／** 此函数将颜色十六进制代码转换为RGB。

- parameter color  hex string.

- returns: RGB color code.
*/
class func getColorFromHex(hexString:String)->UIColor{

    var rgbValue : UInt32 = 0
    let scanner:NSScanner =  NSScanner(string: hexString)

    scanner.scanLocation = 1
    scanner.scanHexInt(&rgbValue)

    return UIColor(red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0, green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0, blue: CGFloat(rgbValue & 0x0000FF) / 255.0, alpha: CGFloat(1.0))
}

}

另一个带有alpha的版本

#define UIColorFromRGBA(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF000000) >> 24))/255.0 green:((float)((rgbValue & 0xFF0000) >> 16))/255.0 blue:((float)((rgbValue & 0xFF00) >> 8 ))/255.0 alpha:((float)((rgbValue & 0xFF))/255.0)]