Answers:
你试过了[myColor isEqual:someOtherColor]吗？
ffffff不等于[UIColor whiteColor]。
正如zoul在评论中指出的那样，当比较不同模型/空间（例如与中）中的颜色时，isEqual:将返回。我编写了这个UIColor扩展，可以在比较它们之前将两种颜色转换为相同的颜色空间：NO#FFF[UIColor whiteColor]
- (BOOL)isEqualToColor:(UIColor *)otherColor {
CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB();
UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) {
if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome) {
const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);
CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]};
CGColorRef colorRef = CGColorCreate( colorSpaceRGB, components );
UIColor *color = [UIColor colorWithCGColor:colorRef];
CGColorRelease(colorRef);
return color;
} else
return color;
};
UIColor *selfColor = convertColorToRGBSpace(self);
otherColor = convertColorToRGBSpace(otherColor);
CGColorSpaceRelease(colorSpaceRGB);
return [selfColor isEqual:otherColor];
}UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) ...正在声明block。他稍后将其用于convertColorToRGBSpace(self)。有关iOS中的块的介绍，请参阅raywenderlich.com/9328/creating-a-diner-app-using-blocks-part-1
这可能为时已晚，但是CoreGraphics有一个更简单的API可以实现此目的：
CGColorEqualToColor(myColor.CGColor, [UIColor clearColor].CGColor)就像文档中说的那样：
指示两种颜色是否相等。如果两种颜色具有相等的色彩空间和数字上相等的颜色分量，则它们是相等的。
这解决了很多麻烦和泄漏/自定义算法。
[UIColor isEqual:]与此相同，不是吗？尽管色彩空间很好，但马克的答案仍然是唯一检查等效性的答案。
UIColor isEqual:如果颜色在不同的颜色空间中，则无济于事。
samvermette的解决方案翻译为swift：
extension UIColor {
func isEqualToColor(otherColor : UIColor) -> Bool {
if self == otherColor {
return true
}
let colorSpaceRGB = CGColorSpaceCreateDeviceRGB()
let convertColorToRGBSpace : ((color : UIColor) -> UIColor?) = { (color) -> UIColor? in
if CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == CGColorSpaceModel.Monochrome {
let oldComponents = CGColorGetComponents(color.CGColor)
let components : [CGFloat] = [ oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1] ]
let colorRef = CGColorCreate(colorSpaceRGB, components)
let colorOut = UIColor(CGColor: colorRef!)
return colorOut
}
else {
return color;
}
}
let selfColor = convertColorToRGBSpace(color: self)
let otherColor = convertColorToRGBSpace(color: otherColor)
if let selfColor = selfColor, otherColor = otherColor {
return selfColor.isEqual(otherColor)
}
else {
return false
}
}
}#import "UIColor-Expanded.h"
//https://github.com/thetaplab/uicolor-utilities
//RGB distance
CGFloat distance = sqrtf(powf((clr0.red - clr1.red), 2) + powf((clr0.green - clr1.green), 2) + powf((clr0.blue - clr1.blue), 2) );
if(distance<=minDistance){
....
}else{
...
}如果比较的颜色可以转换为RGB格式，则在大多数情况下，此UIColor扩展都可以正常工作。
public extension UIColor {
static func == (l: UIColor, r: UIColor) -> Bool {
var l_red = CGFloat(0); var l_green = CGFloat(0); var l_blue = CGFloat(0); var l_alpha = CGFloat(0)
guard l.getRed(&l_red, green: &l_green, blue: &l_blue, alpha: &l_alpha) else { return false }
var r_red = CGFloat(0); var r_green = CGFloat(0); var r_blue = CGFloat(0); var r_alpha = CGFloat(0)
guard r.getRed(&r_red, green: &r_green, blue: &r_blue, alpha: &r_alpha) else { return false }
return l_red == r_red && l_green == r_green && l_blue == r_blue && l_alpha == r_alpha
}
}至少具有此扩展名：
UIColor.whiteColor == UIColor(hex: "#FFFFFF") // true
UIColor.black == UIColor(red: 0, green: 0, blue: 0, alpha: 1) // true如果使用本机UColor.isEqual（...）比较，则两个比较都将返回false。
我写了这个类别。如果isEqual:返回否，它将测试不同组件的进一步比较是否仍然匹配。如果可能，仍将比较不同的模型。
@implementation UIColor (Matching)
-(BOOL)matchesColor:(UIColor *)color error:(NSError *__autoreleasing *)error
{
UIColor *lhs = self;
UIColor *rhs = color;
if([lhs isEqual:rhs]){ // color model and values are the same
return YES;
}
CGFloat red1, red2, green1, alpha1, green2, blue1, blue2, alpha2;
BOOL lhsSuccess = [lhs getRed:&red1 green:&green1 blue:&blue1 alpha:&alpha1];
BOOL rhsSuccess = [rhs getRed:&red2 green:&green2 blue:&blue2 alpha:&alpha2];
if((!lhsSuccess && rhsSuccess) || (lhsSuccess && !rhsSuccess)){ // one is RGBA, one color not.
CGFloat r,g,b,a;
if(!lhsSuccess){ // lhs color could be a monochrome
const CGFloat *components = CGColorGetComponents(lhs.CGColor);
if([lhs _colorSpaceModel] == kCGColorSpaceModelMonochrome){
r = g = b = components[0];
a = components[1];
return r == red2 && g == green2 && b == blue2 && a == alpha2;
}
} else { // rhs color could be a monochrome
const CGFloat *components = CGColorGetComponents(rhs.CGColor);
if([rhs _colorSpaceModel] == kCGColorSpaceModelMonochrome){
r = g = b = components[0];
a = components[1];
return r == red1 && g == green1 && b == blue1 && a == alpha1;
}
}
NSError *aError = [[NSError alloc] initWithDomain:@"UIColorComparision" code:-11111 userInfo:[self _colorComparisionErrorUserInfo]];
*error = aError;
return NO;
} else if (!lhsSuccess && !rhsSuccess){ // both not RGBA, lets try HSBA
CGFloat hue1,saturation1,brightness1;
CGFloat hue2,saturation2,brightness2;
lhsSuccess = [lhs getHue:&hue1 saturation:&saturation1 brightness:&brightness1 alpha:&alpha1];
rhsSuccess = [lhs getHue:&hue2 saturation:&saturation2 brightness:&brightness2 alpha:&alpha2];
if((!lhsSuccess && rhsSuccess) || (lhsSuccess && !rhsSuccess)){
NSError *aError = [[NSError alloc] initWithDomain:@"UIColorComparision" code:-11111 userInfo:[self _colorComparisionErrorUserInfo]];
*error = aError;
return NO;
} else if(!lhsSuccess && !rhsSuccess){ // both not HSBA, lets try monochrome
CGFloat white1, white2;
lhsSuccess = [lhs getWhite:&white1 alpha:&alpha1];
rhsSuccess = [rhs getWhite:&white2 alpha:&alpha2];
if((!lhsSuccess && rhsSuccess) || (lhsSuccess && !rhsSuccess)){
NSError *aError = [[NSError alloc] initWithDomain:@"UIColorComparision" code:-11111 userInfo:[self _colorComparisionErrorUserInfo]];
*error = aError;
return NO;
} else {
return white1 == white2 && alpha1 == alpha2;
}
} else {
return hue1 == hue2 && saturation1 == saturation2 && brightness1 == brightness2 && alpha1 == alpha2;
}
} else {
return (red1 == red2 && green1 == green2 && blue1 == blue2 && alpha1 == alpha2);
}
}
-(NSDictionary *)_colorComparisionErrorUserInfo{
NSDictionary *userInfo = @{
NSLocalizedDescriptionKey: NSLocalizedString(@"Comparision failed.", nil),
NSLocalizedFailureReasonErrorKey: NSLocalizedString(@"The colors models are incompatible. Or the color is a pattern.", nil),
};
return userInfo;
}
- (CGColorSpaceModel)_colorSpaceModel {
return CGColorSpaceGetModel(CGColorGetColorSpace(self.CGColor));
}
@endUIColor *green1 = [UIColor greenColor];
UIColor *green2 = [UIColor colorWithRed:0 green:1 blue:0 alpha:1];
UIColor *yellow = [UIColor yellowColor];
UIColor *grey1 = [UIColor colorWithWhite:2.0/3.0 alpha:1];
UIColor *grey2 = [UIColor lightGrayColor];
NSError *error1, *error2, *error3, *error4, *error5;
BOOL match1 = [green1 matchesColor:green2 error:&error1]; // YES
BOOL match2 = [green1 matchesColor:yellow error:&error2]; // NO
BOOL match3 = [green1 matchesColor:grey1 error:&error3]; // NO
BOOL match4 = [grey1 matchesColor:grey2 error:&error4]; // YES
BOOL match5 = [grey1 matchesColor:[UIColor colorWithPatternImage:[UIImage imageNamed:@"bg.png"]]
error:&error5]; // NO, Error当您
myimage.backgroundColor == [UIColor greenColor]像这样进行比较时，如果尚未在该语句之前将backgroundColor更改为绿色，则它将不起作用。
我在色彩游戏中遇到了同样的问题，我通过在RGB颜色中使用简单的差分方程式解决了这个问题，您可以从这里快速浏览一下简短的代码示例ColorProcess
像胜利者一样回答
GFloat distance = sqrtf(powf((clr0.red - clr1.red), 2) + powf((clr0.green - clr1.green), 2) + powf((clr0.blue - clr1.blue), 2) );
if(distance<=minDistance){
....
}else{
…
}除了该代码示例，您还可以使用
include "UIColorProcess.h"
..
float distance = [UIColorProcess findDistanceBetweenTwoColor:[UIColor redColor] secondColor:[UIColor blueColor]];当然，如果它返回0，则表示您正在比较过于相似的颜色。返回范围类似于（0.0f-1.5f）。
可能会发生一些奇怪的舍入错误。这可能是将对象设置为一种颜色，而将其设置为与之完全不匹配的原因。
这是我解决的方法：
private func compareColors (c1:UIColor, c2:UIColor) -> Bool{
// some kind of weird rounding made the colors unequal so had to compare like this
var red:CGFloat = 0
var green:CGFloat = 0
var blue:CGFloat = 0
var alpha:CGFloat = 0
c1.getRed(&red, green: &green, blue: &blue, alpha: &alpha)
var red2:CGFloat = 0
var green2:CGFloat = 0
var blue2:CGFloat = 0
var alpha2:CGFloat = 0
c2.getRed(&red2, green: &green2, blue: &blue2, alpha: &alpha2)
return (Int(green*255) == Int(green2*255))
}不仅可以通过比较1，还可以通过比较所有组件来改进此代码。例如red + green + blue + alpha == red2 + green2 + blue2 + alpha2
我正在使用此扩展程序，它在所有情况下都适用于我。
/***** UIColor Extension to Compare colors as string *****/
@interface UIColor (compare)
- (BOOL)compareWithColor:(UIColor *)color;
@end
@implementation UIColor(compare)
- (BOOL)compareWithColor:(UIColor *)color {
return ([[[CIColor colorWithCGColor:self.CGColor] stringRepresentation] isEqualToString:[[CIColor colorWithCGColor:color.CGColor] stringRepresentation]]);
}
@end
/**** End ****/希望可以帮助一些人。
注意：此扩展名#ffffff等于[UIColor whiteColor]
其他解决方案无法正常工作。这是在Swift中有效的方法：
import CoreGraphics
extension UIColor {
/**
Checks for visual equality of two colors regardless of their color space.
- parameter color: The other color for comparison.
- returns: A boolean representing whether the colors are visually the same color.
*/
public func isVisuallyEqualTo(_ color: UIColor) -> Bool {
return rgbaComponents == color.rgbaComponents
}
public var rgbaComponents: [CGFloat] {
var data = [CUnsignedChar](repeating: 0, count: 4)
let colorSpace = CGColorSpaceCreateDeviceRGB()
let context = CGContext(data: &data,
width: 1, height: 1,
bitsPerComponent: 8, bytesPerRow: 4,
space: colorSpace,
bitmapInfo: CGImageAlphaInfo.noneSkipLast.rawValue)
context?.setFillColor(cgColor)
context?.fill(CGRect(x: 0, y: 0, width: 1, height: 1))
return data.map { CGFloat($0) / 255.0 }
}
}关于什么：
+(BOOL)color:(UIColor *)color1 matchesColor:(UIColor *)color2
{
CGFloat red1, red2, green1, green2, blue1, blue2, alpha1, alpha2;
[color1 getRed:&red1 green:&green1 blue:&blue1 alpha:&alpha1];
[color2 getRed:&red2 green:&green2 blue:&blue2 alpha:&alpha2];
return (red1 == red2 && green1 == green2 && blue1 == blue2 && alpha1 == alpha2);
}-1如果在调用之后仍然有该值getRed:green:blue:alpha:，则知道比较失败。（或者不要忽略返回的布尔值，因为它会告诉您是否成功调用了它。）
getRed:free:blue:alpha:单色不能成功。因此，您的代码不会产生另一个结果is equal:。请参阅我的答案如何处理。
这是在Swift中切换到RGC空间颜色的扩展：
extension UIColor {
func convertColorToRGBSpaceColor() -> UIColor {
let colorSpaceRGB = CGColorSpaceCreateDeviceRGB()
let oldComponents = CGColorGetComponents(self.CGColor)
let components = [oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]]
let colorRef = CGColorCreate(colorSpaceRGB, components)
let convertedColor = UIColor(CGColor: colorRef!)
return convertedColor
}}
使用Swift 2.2功能扩展到UIColor。但是请注意，由于是比较RGBA值，并且它们是CGFloat，因此舍入错误会使颜色不完全相同（例如，它们最初不是使用init中的完全相同的属性创建的），则返回的颜色不相等。 （...）！）。
/**
Extracts the RGBA values of the colors and check if the are the same.
*/
public func isEqualToColorRGBA(color : UIColor) -> Bool {
//local type used for holding converted color values
typealias colorType = (red : CGFloat, green : CGFloat, blue : CGFloat, alpha : CGFloat)
var myColor : colorType = (0,0,0,0)
var otherColor : colorType = (0,0,0,0)
//getRed returns true if color could be converted so if one of them failed we assume that colors are not equal
guard getRed(&myColor.red, green: &myColor.green, blue: &myColor.blue, alpha: &myColor.alpha) &&
color.getRed(&otherColor.red, green: &otherColor.green, blue: &otherColor.blue, alpha: &otherColor.alpha)
else {
return false
}
log.debug("\(myColor) = \(otherColor)")
//as of Swift 2.2 (Xcode 7.3.1), tuples up to arity 6 can be compared with == so this works nicely
return myColor == otherColor
}UIColor扩展
- (CGFloat)accuracyCompareWith:(UIColor *)color {
CIColor *c1 = [[CIColor alloc] initWithColor:self];
CIColor *c2 = [[CIColor alloc] initWithColor:color];
BOOL hasAlpha = c1.numberOfComponents == 4 && c2.numberOfComponents == 4;
NSInteger numberOfComponents = hasAlpha ? 4 : 3;
CGFloat colorMax = 1.0;
CGFloat p = colorMax / 100.0;
CGFloat redP = fabs(c1.red / p - c2.red / p);
CGFloat greenP = fabs(c1.green / p - c2.green / p);
CGFloat blueP = fabs(c1.blue / p - c2.blue / p);
CGFloat alphaP = 0;
if (hasAlpha)
alphaP = fabs(c1.alpha / p - c2.alpha / p);
return (redP + greenP + blueP + alphaP) / (CGFloat)numberOfComponents;
}我已经将raf对Swift 4 的答案（CGColorAPI 中的许多更改）转换为，由于慷慨地使用，因此消除了力解开并减少了缩进guard：
@extension UIColor {
func isEqualToColor(otherColor: UIColor) -> Bool {
if self == otherColor {
return true
}
let colorSpaceRGB = CGColorSpaceCreateDeviceRGB()
let convertColorToRGBSpace: ((UIColor) -> UIColor?) = { (color) -> UIColor? in
guard color.cgColor.colorSpace?.model == .monochrome else {
return color
}
guard let oldComponents = color.cgColor.components else {
return nil
}
let newComponents = [oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]]
guard let colorRef = CGColor(colorSpace: colorSpaceRGB, components: newComponents) else {
return nil
}
return UIColor(cgColor: colorRef)
}
guard let selfColor = convertColorToRGBSpace(self),
let otherColor = convertColorToRGBSpace(otherColor) else {
return false
}
return selfColor.isEqual(otherColor)
}
}为什么不使用扩展协议添加扩展名？这个答案正在使用Nicolas Miari的解决方案。因此，如果您喜欢这个答案，欢迎您喜欢他的答案（排名第二）
Zoul的评论：以这种方式比较颜色时要小心，因为它们必须处于同一颜色模型中才能被视为相等。例如，＃ffffff不等于[UIColor whiteColor]
static func == (lhs: UIColor, rhs: UIColor) -> Bool {
let colorSpaceRGB = CGColorSpaceCreateDeviceRGB()
let convertColorToRGBSpace: ((UIColor) -> UIColor?) = { (color) -> UIColor? in
guard color.cgColor.colorSpace?.model == .monochrome else {
return color
}
guard let oldComponents = color.cgColor.components else {
return nil
}
let newComponents = [oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]]
guard let colorRef = CGColor(colorSpace: colorSpaceRGB, components: newComponents) else {
return nil
}
return UIColor(cgColor: colorRef)
}
guard let selfColor = convertColorToRGBSpace(lhs),
let otherColor = convertColorToRGBSpace(rhs) else {
return false
}
return selfColor.isEqual(otherColor)
}@samvermette的回答非常好，但我发现在比较不同的颜色类型（在我的情况下UIDeviceRGBColor为UICachedDeviceWhiteColor）时，有时会导致假阴性。我也通过在“ else”中显式创建颜色来修复它：
- (BOOL)isEqualToColor:(UIColor *)otherColor
{
if (self == otherColor)
return YES;
CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB();
UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color)
{
if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome)
{
const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);
CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]};
CGColorRef colorRef = CGColorCreate(colorSpaceRGB, components);
UIColor *color = [UIColor colorWithCGColor:colorRef];
CGColorRelease(colorRef);
return color;
}
else
{
const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);
CGFloat components[4] = {oldComponents[0], oldComponents[1], oldComponents[2], oldComponents[3]};
CGColorRef colorRef = CGColorCreate(colorSpaceRGB, components);
UIColor *color = [UIColor colorWithCGColor:colorRef];
CGColorRelease(colorRef);
return color;
}
};
UIColor *selfColor = convertColorToRGBSpace(self);
otherColor = convertColorToRGBSpace(otherColor);
CGColorSpaceRelease(colorSpaceRGB);
return [selfColor isEqual:otherColor];
}