我该如何从十六进制字符串格式(例如#00FF00
)创建一个UIColor
呢?
我该如何从十六进制字符串格式(例如#00FF00
)创建一个UIColor
呢?
我发现了一个适用于此的很好的UIColor
类别,UIColor+PXExtensions。
用法:UIColor *mycolor = [UIColor pxColorWithHexValue:@"#BADA55"];
而且,以防我的代码片段链接失效,以下是实际实现代码:
//
// UIColor+PXExtensions.m
//
#import "UIColor+UIColor_PXExtensions.h"
@implementation UIColor (UIColor_PXExtensions)
+ (UIColor*)pxColorWithHexValue:(NSString*)hexValue
{
//Default
UIColor *defaultResult = [UIColor blackColor];
//Strip prefixed # hash
if ([hexValue hasPrefix:@"#"] && [hexValue length] > 1) {
hexValue = [hexValue substringFromIndex:1];
}
//Determine if 3 or 6 digits
NSUInteger componentLength = 0;
if ([hexValue length] == 3)
{
componentLength = 1;
}
else if ([hexValue length] == 6)
{
componentLength = 2;
}
else
{
return defaultResult;
}
BOOL isValid = YES;
CGFloat components[3];
//Seperate the R,G,B values
for (NSUInteger i = 0; i < 3; i++) {
NSString *component = [hexValue substringWithRange:NSMakeRange(componentLength * i, componentLength)];
if (componentLength == 1) {
component = [component stringByAppendingString:component];
}
NSScanner *scanner = [NSScanner scannerWithString:component];
unsigned int value;
isValid &= [scanner scanHexInt:&value];
components[i] = (CGFloat)value / 256.0f;
}
if (!isValid) {
return defaultResult;
}
return [UIColor colorWithRed:components[0]
green:components[1]
blue:components[2]
alpha:1.0];
}
@end
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))
}
扩展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))
}
}
如何调用。let hexColorFromFunction = UIColorFromRGB("F4C124", alpha: 1.0)
let hexColorFromExtension = UIColor(colorCode: "F4C124", alpha: 1.0)
您还可以在界面构建器中定义您的十六进制颜色
。
SWIFT 4
您可以在扩展中创建一个漂亮的convenience
构造函数,像这样:
extension UIColor {
convenience init(hexString: String, alpha: CGFloat = 1.0) {
var hexInt: UInt32 = 0
let scanner = Scanner(string: hexString)
scanner.charactersToBeSkipped = CharacterSet(charactersIn: "#")
scanner.scanHexInt32(&hexInt)
let red = CGFloat((hexInt & 0xff0000) >> 16) / 255.0
let green = CGFloat((hexInt & 0xff00) >> 8) / 255.0
let blue = CGFloat((hexInt & 0xff) >> 0) / 255.0
let alpha = alpha
self.init(red: red, green: green, blue: blue, alpha: alpha)
}
}
然后将其保存以便日后使用
let color = UIColor(hexString: "#AABBCCDD")
这是另一种选择。
- (UIColor *)colorWithRGBHex:(UInt32)hex
{
int r = (hex >> 16) & 0xFF;
int g = (hex >> 8) & 0xFF;
int b = (hex) & 0xFF;
return [UIColor colorWithRed:r / 255.0f
green:g / 255.0f
blue:b / 255.0f
alpha:1.0f];
}
您可以使用各种在线工具将HEX字符串转换为实际的UIColor。请查阅uicolor.org或UI Color Picker。输出结果将被转换为Objective-C代码,例如:
[UIColor colorWithRed:0.93 green:0.80 blue:0.80 alpha:1.0];
你可以将此嵌入你的应用程序中。希望这有所帮助!
这个很赞,支持 CocoaPods
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]
这是一个针对 UIColor
的扩展,适用于 Swift 1.2
。它使您能够执行以下操作:
let redColor = UIColor(hex: "#FF0000")
extension UIColor {
// Initialiser for strings of format '#_RED_GREEN_BLUE_'
convenience init(hex: String) {
let redRange = Range<String.Index>(start: hex.startIndex.advancedBy(1), end: hex.startIndex.advancedBy(3))
let greenRange = Range<String.Index>(start: hex.startIndex.advancedBy(3), end: hex.startIndex.advancedBy(5))
let blueRange = Range<String.Index>(start: hex.startIndex.advancedBy(5), end: hex.startIndex.advancedBy(7))
var red : UInt32 = 0
var green : UInt32 = 0
var blue : UInt32 = 0
NSScanner(string: hex.substringWithRange(redRange)).scanHexInt(&red)
NSScanner(string: hex.substringWithRange(greenRange)).scanHexInt(&green)
NSScanner(string: hex.substringWithRange(blueRange)).scanHexInt(&blue)
self.init(
red: CGFloat(red) / 255,
green: CGFloat(green) / 255,
blue: CGFloat(blue) / 255,
alpha: 1
)
}
}
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)
}
另一个带有透明度的版本
#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)]
以下是Swift版本的@Tom答案,支持透明度RGBA Int值:
func colorWithHex(aHex: UInt) -> UIColor
{
return UIColor(red: CGFloat((aHex & 0xFF000000) >> 24) / 255,
green: CGFloat((aHex & 0x00FF0000) >> 16) / 255,
blue: CGFloat((aHex & 0x0000FF00) >> 8) / 255,
alpha: CGFloat((aHex & 0x000000FF) >> 0) / 255)
}
//usage
var color = colorWithHex(0x7F00FFFF)
如果您想从字符串中使用它,您可以使用strtoul:
var hexString = "0x7F00FFFF"
let num = strtoul(hexString, nil, 16)
var colorFromString = colorWithHex(num)