How can I create a UIColor from a hex string?

2018-12-31 23:33发布

How can I create a UIColor from a hexadecimal string format, such as #00FF00?

30条回答
柔情千种
2楼-- · 2018-12-31 23:51
 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;
    }
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泛滥B
3楼-- · 2018-12-31 23:52

swift version. Use as a Function or an Extension.

Function
  func UIColorFromRGB(colorCode: String, alpha: Float = 1.0) -> UIColor{
    var scanner = NSScanner(string:colorCode)
    var color:UInt32 = 0;
    scanner.scanHexInt(&color)

    let mask = 0x000000FF
    let r = CGFloat(Float(Int(color >> 16) & mask)/255.0)
    let g = CGFloat(Float(Int(color >> 8) & mask)/255.0)
    let b = CGFloat(Float(Int(color) & mask)/255.0)

    return UIColor(red: r, green: g, blue: b, alpha: CGFloat(alpha))
}
Extension
extension UIColor {
    convenience init(colorCode: String, alpha: Float = 1.0){
        var scanner = NSScanner(string:colorCode)
        var color:UInt32 = 0;
        scanner.scanHexInt(&color)

        let mask = 0x000000FF
        let r = CGFloat(Float(Int(color >> 16) & mask)/255.0)
        let g = CGFloat(Float(Int(color >> 8) & mask)/255.0)
        let b = CGFloat(Float(Int(color) & mask)/255.0)

        self.init(red: r, green: g, blue: b, alpha: CGFloat(alpha))
    }
}
How to call
let hexColorFromFunction = UIColorFromRGB("F4C124", alpha: 1.0)
let hexColorFromExtension = UIColor(colorCode: "F4C124", alpha: 1.0)
You can also define your Hex Color from interface builder.

enter image description here

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刘海飞了
4楼-- · 2018-12-31 23:53

This is nice with cocoapod support

https://github.com/mRs-/HexColors

// with hash
NSColor *colorWithHex = [NSColor colorWithHexString:@"#ff8942" alpha:1];

// wihtout hash
NSColor *secondColorWithHex = [NSColor colorWithHexString:@"ff8942" alpha:1];

// short handling
NSColor *shortColorWithHex = [NSColor colorWithHexString:@"fff" alpha:1]
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十年一品温如言
5楼-- · 2018-12-31 23:54

updated for swift 1.2

class func colorWithHexString (hex:String) -> UIColor {
    var cString: NSString = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()).uppercaseString

    if (cString.hasPrefix("#")) {
        cString = cString.substringFromIndex(1)
    }

    if (count(cString as String) != 6) {
        return UIColor.grayColor()
    }

    var rString: String = cString.substringToIndex(2)
    var gString: String = (cString.substringFromIndex(2) as NSString).substringToIndex(2)
    var bString: String = (cString.substringFromIndex(4) as NSString).substringToIndex(2)

    var r:CUnsignedInt = 0, g:CUnsignedInt = 0, b:CUnsignedInt = 0;
    NSScanner(string: rString).scanHexInt(&r)
    NSScanner(string: gString).scanHexInt(&g)
    NSScanner(string: bString).scanHexInt(&b)
    return UIColor(red: CGFloat(Float(r) / 255.0), green: CGFloat(Float(g) / 255.0), blue: CGFloat(Float(b) / 255.0), alpha: CGFloat(1))

}
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看风景的人
6楼-- · 2018-12-31 23:56

You could use various online tools to convert a HEX string to an actual UIColor. Check out uicolor.org or UI Color Picker. The output would be converted into Objective-C code, like:

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

Which you could embed in your application. Hope this helps!

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低头抚发
7楼-- · 2018-12-31 23:56

Another version with alpha

#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)]
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