我已经检查了几个关于如何将 UIColor 代码转换为 HEX 的链接,但是我不确定如何调用该方法以在 NSLog 中显示它们。我没有评论的声誉,所以作为问题发布是我最后的手段。 我希望它在我在日志中运行我的应用程序时显示。
其次,我在哪里输入RGB颜色编号(R = 30,G = 171,B = 13)?我看到所有示例都使用 Array [0], [1], [2] 通常指的是索引位置,那么我在哪里添加颜色值?
我有这个代码:
- (NSString *) hexFromUIColor:(UIColor *)color {
if (CGColorGetNumberOfComponents(color.CGColor) < 4) {
const CGFloat *components = CGColorGetComponents(color.CGColor);
color = [UIColor colorWithRed:components[30] green:components[141] blue:components[13] alpha:components[1]];
}
if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) != kCGColorSpaceModelRGB) {
return [NSString stringWithFormat:@"#FFFFFF"];
}
return [NSString stringWithFormat:@"#%02X%02X%02X", (int)((CGColorGetComponents(color.CGColor))[0]*255.0), (int)((CGColorGetComponents(color.CGColor))[1]*255.0), (int)((CGColorGetComponents(color.CGColor))[2]*255.0)];
}
我检查过的链接:
How to convert HEX RGB color codes to UIColor?
我尝试在 viewDidLoad 中调用该方法,但是如果没有 UIColor,它将无法工作。我相信这很简单。
感谢任何回答的人。
为了在 NSLog 中显示,我在 viewDidLoad 中使用什么代码调用此方法?
最佳答案
swift 5:
func hexStringFromColor(color: UIColor) -> String {
let components = color.cgColor.components
let r: CGFloat = components?[0] ?? 0.0
let g: CGFloat = components?[1] ?? 0.0
let b: CGFloat = components?[2] ?? 0.0
let hexString = String.init(format: "#%02lX%02lX%02lX", lroundf(Float(r * 255)), lroundf(Float(g * 255)), lroundf(Float(b * 255)))
print(hexString)
return hexString
}
func colorWithHexString(hexString: String) -> UIColor {
var colorString = hexString.trimmingCharacters(in: .whitespacesAndNewlines)
colorString = colorString.replacingOccurrences(of: "#", with: "").uppercased()
print(colorString)
let alpha: CGFloat = 1.0
let red: CGFloat = self.colorComponentFrom(colorString: colorString, start: 0, length: 2)
let green: CGFloat = self.colorComponentFrom(colorString: colorString, start: 2, length: 2)
let blue: CGFloat = self.colorComponentFrom(colorString: colorString, start: 4, length: 2)
let color = UIColor(red: red, green: green, blue: blue, alpha: alpha)
return color
}
func colorComponentFrom(colorString: String, start: Int, length: Int) -> CGFloat {
let startIndex = colorString.index(colorString.startIndex, offsetBy: start)
let endIndex = colorString.index(startIndex, offsetBy: length)
let subString = colorString[startIndex..<endIndex]
let fullHexString = length == 2 ? subString : "\(subString)\(subString)"
var hexComponent: UInt32 = 0
guard Scanner(string: String(fullHexString)).scanHexInt32(&hexComponent) else {
return 0
}
let hexFloat: CGFloat = CGFloat(hexComponent)
let floatValue: CGFloat = CGFloat(hexFloat / 255.0)
print(floatValue)
return floatValue
}
如何使用
let red = CGFloat(30.0)
let green = CGFloat(171.0)
let blue = CGFloat(13.0)
let alpha = CGFloat(1.0)
let color = UIColor(red: CGFloat(red/255.0), green: CGFloat(green/255.0), blue: CGFloat(blue / 255.0), alpha: alpha)
let colorCode = self.hexStringFromColor(color: color)
print(colorCode)
let resultColor = self.colorWithHexString(hexString: colorCode)
print(resultColor)
objective-C :
- (NSString *)hexStringFromColor:(UIColor *)color {
const CGFloat *components = CGColorGetComponents(color.CGColor);
CGFloat r = components[0];
CGFloat g = components[1];
CGFloat b = components[2];
return [NSString stringWithFormat:@"#%02lX%02lX%02lX",
lroundf(r * 255),
lroundf(g * 255),
lroundf(b * 255)];
}
获取十六进制代码字符串后,调用下面的方法获取UIColor
- (UIColor *) colorWithHexString: (NSString *) hexString
{
NSString *colorString = [[hexString stringByReplacingOccurrencesOfString: @"#" withString: @""] uppercaseString];
NSLog(@"colorString :%@",colorString);
CGFloat alpha, red, blue, green;
// #RGB
alpha = 1.0f;
red = [self colorComponentFrom: colorString start: 0 length: 2];
green = [self colorComponentFrom: colorString start: 2 length: 2];
blue = [self colorComponentFrom: colorString start: 4 length: 2];
return [UIColor colorWithRed: red green: green blue: blue alpha: alpha];
}
- (CGFloat) colorComponentFrom: (NSString *) string start: (NSUInteger) start length: (NSUInteger) length {
NSString *substring = [string substringWithRange: NSMakeRange(start, length)];
NSString *fullHex = length == 2 ? substring : [NSString stringWithFormat: @"%@%@", substring, substring];
unsigned hexComponent;
[[NSScanner scannerWithString: fullHex] scanHexInt: &hexComponent];
return hexComponent / 255.0;
}
如何使用
// ( R = 30, G = 171, B = 13)?
CGFloat red = 30.0;
CGFloat green = 171.0;
CGFloat blue = 13.0;
CGFloat alpha = 255.0
UIColor *color = [UIColor colorWithRed:(red/255.0) green:(green/255.0) blue:(blue/255.0) alpha:(alpha/255.0)];
NSString *colorCode = [self hexStringFromColor:color];
NSLog(@"Color Code: %@", colorCode);
UIColor *resultColor = [self colorWithHexString:colorCode];
关于ios - 如何将 UIColor 转换为 HEX 并在 NSLog 中显示,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26341008/