UIColor各种颜色转换

1、Hex值颜色转换

#import <UIKit/UIKit.h>

@interface UIColor (Extension)

// 根据无符号的32位整数转换为对应的RGB颜色
+ (instancetype)sy_colorWithHex:(u_int32_t)hex;

@end

#import "UIColor+Extension.h"

@implementation UIColor (Extension)

+ (instancetype)sy_colorWithHex:(u_int32_t)hex{

    int red = (hex & 0xFF0000) >> 16;
    int green = (hex & 0x00FF00) >> 8;
    int blue = hex & 0x0000FF;

    return [UIColor colorWithRed:red/255.0 green:green/255.0 blue:blue/255.0 alpha:1.0];
}

@end

2、将UIColor转换为RGB值

- (NSMutableArray *) changeUIColorToRGB:(UIColor *)color
{
    NSMutableArray *RGBStrValueArr = [[NSMutableArray alloc] init];
    NSString *RGBStr = nil;  

    //获得RGB值描述
    NSString *RGBValue = [NSString stringWithFormat:@"%@",color];  

    //将RGB值描述分隔成字符串
    NSArray *RGBArr = [RGBValue componentsSeparatedByString:@" "];

    //获取红色值
    int r = [[RGBArr objectAtIndex:1] intValue] * 255;
    RGBStr = [NSString stringWithFormat:@"%d",r];
    [RGBStrValueArr addObject:RGBStr];  

    //获取绿色值
    int g = [[RGBArr objectAtIndex:2] intValue] * 255;
    RGBStr = [NSString stringWithFormat:@"%d",g];
    [RGBStrValueArr addObject:RGBStr];  

    //获取蓝色值
    int b = [[RGBArr objectAtIndex:3] intValue] * 255;
    RGBStr = [NSString stringWithFormat:@"%d",b];
    [RGBStrValueArr addObject:RGBStr];  

    //返回保存RGB值的数组
    return [RGBStrValueArr autorelease];
}

3、16进制颜色(html颜色值)字符串转为UIColor

+(UIColor *) hexStringToColor: (NSString *) stringToConvert
{
     NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
     // String should be 6 or 8 characters  

     if ([cString length] < 6) return [UIColor blackColor];
     // strip 0X if it appears
     if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];
     if ([cString hasPrefix:@"#"]) cString = [cString substringFromIndex:1];
     if ([cString length] != 6) return [UIColor blackColor];  

     // Separate into r, g, b substrings  

     NSRange range;
     range.location = 0;
     range.length = 2;
     NSString *rString = [cString substringWithRange:range];
     range.location = 2;
     NSString *gString = [cString substringWithRange:range];
     range.location = 4;
     NSString *bString = [cString 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];
}