// 方法一

#define UIColorFromRGBValue(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 green:((float)((rgbValue & 0xFF00) >> 8))/255.0 blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]

使用

UIColorFromRGBValue（0xff9719）

// 方法二

右键点击new file--》选择objective-c file--》创建类 category--》起个名字HexadecimalColor--》class处选择UIColor--》点击create--》

.h文件实现方法--》

@interface UIColor (HexadecimalColor)

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

@end

--》在.m文件中实现方法具体如下--》

#import "UIColor+HexadecimalColor.h"

@implementation UIColor (HexadecimalColor)

//实现方法

+ (UIColor *)colorWithHexString:(NSString *)color alpha:(CGFloat)alpha

{

    //删除字符串中的空格

    //    NSString*cString = [[color stringByTrimmingCharactersInSet[NSCharacterSet         whitespaceAndNewlineCharacterSet]] uppercaseString];

    NSString*cString = [color stringByTrimmingCharactersInSet:[NSCharacterSetwhitespaceAndNewlineCharacterSet]];

    // String should be 6 or 8 characters

    if ([cString length] < 6)

    {

        return [UIColor clearColor];

    }

    // strip 0X if it appears

    //如果是0x开头的，那么截取字符串，字符串从索引为2的位置开始，一直到末尾

    if ([cString hasPrefix:@"0X"])

    {

        cString = [cString substringFromIndex:2];

    }

    //如果是#开头的，那么截取字符串，字符串从索引为1的位置开始，一直到末尾

    if ([cString hasPrefix:@"#"])

    {

        cString = [cString substringFromIndex:1];

    }

    if ([cString length] != 6)

    {

        return [UIColor clearColor];

    }

    // Separate into r, g, b substrings

    NSRange range;

    range.location = 0;

    range.length = 2;

    //r

    NSString *rString = [cString substringWithRange:range];

    //g

    range.location = 2;

    NSString *gString = [cString substringWithRange:range];

    //b

    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:alpha];

}

@end