iOS 分类之UIColor+Hex

//
//  UIColor+Hex.h
//  ColorDemo
//
//  Created by 黄健 on 16/7/22.
//  Copyright © 2016年 黄健. All rights reserved.
//

#import <UIKit/UIKit.h>

#define HexRandomColor         [UIColor hj_randomColor]
#define HexStringColor(string) [UIColor hj_colorWithHexString:string]
#define HexRGBColor(R, G, B)   [UIColor hj_colorWith8BitRed:R green:G blue:B]

@interface UIColor (Hex)

+ (UIColor *)hj_randomColor;

+ (UIColor *)hj_colorWithHexString:(NSString *)color;
+ (UIColor *)hj_colorWithHexString:(NSString *)color alpha:(CGFloat)alpha;

+ (UIColor *)hj_colorWith8BitRed:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue;
+ (UIColor *)hj_colorWith8BitRed:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue alpha:(CGFloat)alpha;

@end

//
//  UIColor+Hex.m
//  ColorDemo
//
//  Created by 黄健 on 16/7/22.
//  Copyright © 2016年 黄健. All rights reserved.
//

#import "UIColor+Hex.h"

@implementation UIColor (Hex)

+ (UIColor *)hj_randomColor
{
CGFloat R = arc4random_uniform(256) / 255.0;
CGFloat G = arc4random_uniform(256) / 255.0;
CGFloat B = arc4random_uniform(256) / 255.0;

return [[self class] colorWithRed:R green:G blue:B alpha:1];
}

+ (UIColor *)hj_colorWithHexString:(NSString *)color alpha:(CGFloat)alpha
{
NSString *cString = [[color stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];

if ([cString length] < 6)
{
return [UIColor clearColor];
}

if ([cString hasPrefix:@"0x"] || [cString hasPrefix:@"0X"])
{
cString = [cString substringFromIndex:2];
}

if ([cString hasPrefix:@"#"])
{
cString = [cString substringFromIndex:1];
}

if ([cString length] != 6)
{
return [UIColor clearColor];
}

NSRange range;
range.length = 2;

range.location = 0;
NSString *rString = [cString substringWithRange:range];

range.location = 2;
NSString *gString = [cString substringWithRange:range];

range.location = 4;
NSString *bString = [cString substringWithRange:range];

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:alpha];
}

+ (UIColor *)hj_colorWithHexString:(NSString *)color
{
return [[self class] hj_colorWithHexString:color alpha:1.f];
}

+ (UIColor *)hj_colorWith8BitRed:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue alpha:(CGFloat)alpha
{
return [UIColor colorWithRed:(float)red/255 green:(float)green/255 blue:(float)blue/255 alpha:alpha];
}

+ (UIColor *)hj_colorWith8BitRed:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue
{
return [[self class] hj_colorWith8BitRed:red green:green blue:blue alpha:1.f];
}

@end