ios UILabel指定文字变色

NSString * noticeStr = [NSString stringWithFormat:@"将获得￥%@",[YZHttpmanager positiveFormat:amountStr]];
    NSArray *number = @[@"0",@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@".",@",",@"￥"];
    NSMutableAttributedString *attributeString  = [[NSMutableAttributedString alloc]initWithString:noticeStr];
    for (int i = 0; i < noticeStr.length; i ++) {
        //这里的小技巧，每次只截取一个字符的范围
        NSString *a = [noticeStr substringWithRange:NSMakeRange(i, 1)];
        //判断装有0-9的字符串的数字数组是否包含截取字符串出来的单个字符，从而筛选出符合要求的数字字符的范围NSMakeRange
        if ([number containsObject:a]) {
            [attributeString setAttributes:@{NSForegroundColorAttributeName:UIColorFromRGB(0xFF5A00),NSFontAttributeName:[UIFont boldSystemFontOfSize:25],NSUnderlineStyleAttributeName:[NSNumber numberWithInteger:0]} range:NSMakeRange(i, 1)];
        }
    }
    amountlab.attributedText=attributeString;