IOS直接使用美工给的16位制颜色代码

加入一个分类：

#import <UIKit/UIKit.h>

@interface UIColor (ColorWithString)

+(UIColor *)colorWithString:(NSString *)string;

@end

#import "UIColor+ColorWithString.h"

@implementation UIColor (ColorWithString)

+(UIColor *)colorWithString:(NSString *)string{
    if ([string isKindOfClass:[NSString class]]) {
        string = [string stringByReplacingOccurrencesOfString:@"'" withString:@""];
        if ([string hasPrefix:@"#"]) {
            const char *s = [string cStringUsingEncoding:NSASCIIStringEncoding];
            if (*s == '#') {
                ++s;
            }
            unsigned long long value = strtoll(s, nil, 16);
            int r, g, b, a;
            switch (strlen(s)) {
                case 2:
                    // xx
                    r = g = b = (int)value;
                    a = 255;
                    break;
                case 3:
                    // RGB
                    r = ((value & 0xf00) >> 8);
                    g = ((value & 0x0f0) >> 4);
                    b = ((value & 0x00f) >> 0);
                    r = r * 16 + r;
                    g = g * 16 + g;
                    b = b * 16 + b;
                    a = 255;
                    break;
                case 6:
                    // RRGGBB
                    r = (value & 0xff0000) >> 16;
                    g = (value & 0x00ff00) >>  8;
                    b = (value & 0x0000ff) >>  0;
                    a = 255;
                    break;
                default:
                    // RRGGBBAA
                    r = (value & 0xff000000) >> 24;
                    g = (value & 0x00ff0000) >> 16;
                    b = (value & 0x0000ff00) >>  8;
                    a = (value & 0x000000ff) >>  0;
                    break;
            }
            return [UIColor colorWithRed:r/255.0f green:g/255.0f blue:b/255.0f alpha:a/255.0f];
        }
        else
        {
            string = [string stringByAppendingString:@"Color"];
            SEL colorSel = NSSelectorFromString(string);
            if ([UIColor respondsToSelector:colorSel]) {
                return [UIColor performSelector:colorSel];
            }
   return nil;
        }
    } else if([string isKindOfClass:[UIColor class]]){
        return (UIColor *)string;
    }
    return nil;
}

导入这个分类，然后直接使用：

//例子
view.backgroundColor =  [UIColor colorWithString:@"#EBEBF1"];