[UIColor colorWithRed:(r)/255.0 green:(g)/255.0 blue:(b)/255.0 alpha:1];
UIColor只提供了上面的方法用于创建一个RGBA的颜色值，但是开发中大部分用的是喜闻乐见的16进制的字符串或者整数，例如：
LightPink 浅粉红 #FFB6C1 255,182,193
Indigo 靛青 #4B0082 75,0,130
所以使用分类去增加一些方法让颜色的转换更加方便势在必行。
使用示例：
#import "UIColor+Utils.h"
- (void)testColors {
UIColor *color = RGBHex(0x334422);
ARGBHex(0xffccaabb);
// UIColor *color = [UIColor colorWithHexRGB:(0xFFC0CB)];
UIColor *colorTest = [UIColor colorWithHexARGB:0xFFCACBCE];
NSLog(@"%@",color);
NSLog(@" RGB:%@, ARGB:%@",[color toHexRGB], [color toHexARGB]);
NSLog(@"A:%0x, R:%0x, G:%0x, B:%0x ", [color toRGBA].a, [color toRGBA].r, [color toRGBA].g,[color toRGBA].b);
}
具体实现代码如下：
//
// UIColor+Utils.h
//
// Created by Jokerlee on 2018/6/28.
// Copyright © 2018年 Jokerlee. All rights reserved.
//
#import <UIKit/UIKit.h>
struct RGBA {
UInt8 r;
UInt8 g;
UInt8 b;
UInt8 a;
};
@interface UIColor (Utils)
//---------------------------------------------------------------------------
#pragma mark macros for generating colors
//---------------------------------------------------------------------------
#define RGBInt(r,g,b) [UIColor colorWithRed:(r)/255.0 green:(g)/255.0 blue:(b)/255.0 alpha:1]
#define RGBAInt(r,g,b,a) [UIColor colorWithRed:(r)/255.0 green:(g)/255.0 blue:(b)/255.0 alpha:(a)/255.0]
#define RGBHex(rgb) [UIColor colorWithHexRGB:rgb]
#define RGBAHex(rgba) [UIColor colorWithHexRGBA:rgba]
#define ARGBHex(argb) [UIColor colorWithHexARGB:argb]
//---------------------------------------------------------------------------
#pragma mark methods for generating colors
//---------------------------------------------------------------------------
+ (UIColor *)colorWithHexRGB:(NSUInteger)hexRGB;
+ (UIColor *)colorWithHexRGBA:(NSUInteger)hexRGBA;
+ (UIColor *)colorWithHexARGB:(NSUInteger)hexARGB;
+ (UIColor *)colorWithHexStringRGB:(NSString *)hexRGB;
//---------------------------------------------------------------------------
#pragma mark methods for color converting
//---------------------------------------------------------------------------
- (NSString *)toHexRGB;
- (NSString *)toHexRGBA;
- (NSString *)toHexARGB;
- (struct RGBA)toRGBA;
@end
//
// UIColor+Utils.m
//
// Created by Jokerlee on 2018/6/28.
// Copyright © 2018年 Jokerlee. All rights reserved.
//
#import "UIColor+Utils.h"
@implementation UIColor (Utils)
+ (UIColor *)colorWithIntegerRed:(NSUInteger)red green:(NSUInteger)green blue:(NSUInteger)blue {
return [UIColor colorWithRed:red/255.0f green:green/255.0f blue:blue/255.0f alpha:1.0f];
}
+ (UIColor *)colorWithIntegerRed:(NSUInteger)red green:(NSUInteger)green blue:(NSUInteger)blue alpha:(CGFloat)alpha {
return [UIColor colorWithRed:red/255.0f green:green/255.0f blue:blue/255.0f alpha:alpha];
}
+ (UIColor *)colorWithHexRGB:(NSUInteger)hexRGB {
return [UIColor colorWithIntegerRed:((hexRGB & 0xFF0000) >> 16) green:((hexRGB & 0x00FF00) >> 8) blue:(hexRGB & 0x0000FF) alpha:1.0f];
}
+ (UIColor *)colorWithHexRGBA:(NSUInteger)hexRGBA {
return [UIColor colorWithIntegerRed:((hexRGBA & 0xFF000000) >> 24) green:((hexRGBA & 0x00FF0000) >> 16) blue:((hexRGBA & 0x0000FF00) >> 8) alpha:(hexRGBA & 0x000000FF)/255.0f];
}
+ (UIColor *)colorWithHexARGB:(NSUInteger)hexARGB {
return [UIColor colorWithIntegerRed:((hexARGB & 0x00FF0000) >> 16) green:((hexARGB & 0x0000FF00) >> 8) blue:(hexARGB & 0x000000FF) alpha:((hexARGB & 0xFF000000) >> 24)/255.0f];
}
- (NSString *)toHexRGB {
CGColorRef color = self.CGColor;
size_t count = CGColorGetNumberOfComponents(color);
const CGFloat *components = CGColorGetComponents(color);
static NSString *stringFormat = @"%02x%02x%02x";
if (count == 2) {
// Grayscale
NSUInteger grey = (NSUInteger)(components[0] * (CGFloat)255);
return [NSString stringWithFormat:stringFormat, grey, grey, grey];
}
else if (count == 4) {
// RGB
return [NSString stringWithFormat:stringFormat,
(NSUInteger)(components[0] * (CGFloat)255),
(NSUInteger)(components[1] * (CGFloat)255),
(NSUInteger)(components[2] * (CGFloat)255)];
}
// Unsupported color space
return nil;
}
- (NSString *)toHexARGB {
CGColorRef color = self.CGColor;
size_t count = CGColorGetNumberOfComponents(color);
const CGFloat *components = CGColorGetComponents(color);
static NSString *stringFormat = @"%02x%02x%02x%02x";
if (count == 2) {
// Grayscale
NSUInteger grey = (NSUInteger)(components[0] * (CGFloat)255);
NSUInteger alpha = (NSUInteger)(components[3] * (CGFloat)255);
return [NSString stringWithFormat:stringFormat, grey, grey, grey, alpha];
}
else if (count == 4) {
// RGBA
return [NSString stringWithFormat:stringFormat,
(NSUInteger)(components[3] * (CGFloat)255),
(NSUInteger)(components[0] * (CGFloat)255),
(NSUInteger)(components[1] * (CGFloat)255),
(NSUInteger)(components[2] * (CGFloat)255)];
}
// Unsupported color space
return nil;
}
- (NSString *)toHexRGBA {
CGColorRef color = self.CGColor;
size_t count = CGColorGetNumberOfComponents(color);
const CGFloat *components = CGColorGetComponents(color);
static NSString *stringFormat = @"%02x%02x%02x%02x";
if (count == 2) {
// Grayscale
NSUInteger grey = (NSUInteger)(components[0] * (CGFloat)255);
NSUInteger alpha = (NSUInteger)(components[3] * (CGFloat)255);
return [NSString stringWithFormat:stringFormat, grey, grey, grey, alpha];
}
else if (count == 4) {
// RGBA
return [NSString stringWithFormat:stringFormat,
(NSUInteger)(components[0] * (CGFloat)255),
(NSUInteger)(components[1] * (CGFloat)255),
(NSUInteger)(components[2] * (CGFloat)255),
(NSUInteger)(components[3] * (CGFloat)255)];
}
// Unsupported color space
return nil;
}
- (struct RGBA)toRGBA {
struct RGBA rgba = {0,0,0,0};
CGColorRef color = self.CGColor;
size_t count = CGColorGetNumberOfComponents(color);
const CGFloat *components = CGColorGetComponents(color);
if (count == 2) {
// Grayscale
NSUInteger grey = (NSUInteger)(components[0] * (CGFloat)255);
NSUInteger alpha = (NSUInteger)(components[3] * (CGFloat)255);
rgba.a = alpha;
rgba.r = grey;
rgba.g = grey;
rgba.b = grey;
return rgba;
} else if (count == 4) {
// RGBA
rgba.a = (NSUInteger)(components[3] * (CGFloat)255);
rgba.r = (NSUInteger)(components[0] * (CGFloat)255);
rgba.g = (NSUInteger)(components[1] * (CGFloat)255);
rgba.b = (NSUInteger)(components[2] * (CGFloat)255);
return rgba;
}
// Unsupported color space
return rgba;
}
+ (UIColor *)colorWithHexStringRGB:(NSString *)hexColor {
if(!hexColor || [hexColor isKindOfClass:[NSNull class]]){
return [UIColor blackColor];
}
hexColor = [[hexColor stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
// String should be 6 or 7 characters if it includes '#'
if ([hexColor length] < 6)
return [UIColor blackColor];
// strip # if it appears
if ([hexColor hasPrefix:@"#"])
hexColor = [hexColor substringFromIndex:1];
// if the value isn't 6 characters at this point return
// the color black
if ([hexColor length] != 6)
return [UIColor blackColor];
// Separate into r, g, b substrings
NSRange range;
range.location = 0;
range.length = 2;
NSString *rString = [hexColor substringWithRange:range];
range.location = 2;
NSString *gString = [hexColor substringWithRange:range];
range.location = 4;
NSString *bString = [hexColor substringWithRange:range];
// Scan values
unsigned int r, g, b;
[[NSScanner scannerWithString:rString] scanHexInt:&r];
[[NSScanner scannerWithString:gString] scanHexInt:&g];
[[NSScanner scannerWithString:bString] scanHexInt:&b];
return [UIColor colorWithRed:((float) r / 255.0f)
green:((float) g / 255.0f)
blue:((float) b / 255.0f)
alpha:1.0f];
}
@end
