iOS 改变UILabel部分颜色

//协议

UILabel *xieLabel = [[UILabel alloc] init];

xieLabel.textColor = TextGrayColor;

xieLabel.font = [UIFont systemFontOfSize:12];

NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"我已阅读并同意《存工资服务协议》"];

[string addAttribute:NSForegroundColorAttributeName value:[UIColor lightGrayColor] range:NSMakeRange(0, 7)];

[string addAttribute:NSForegroundColorAttributeName value:[UIColor orangeColor] range:NSMakeRange(7, string.length - 7)];

xieLabel.attributedText = string;

xieLabel.userInteractionEnabled = YES;

UITapGestureRecognizer *xieyitap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(xiyiAction)];

[xieLabel addGestureRecognizer:xieyitap];