属性字符串

属性字符串的使用：

 if(!_pwdButton) {        _pwdButton = [UIButton buttonWithType:UIButtonTypeSystem];        NSMutableDictionary *dic = [[NSMutableDictionary alloc]init];        //设置下划线的颜色        dic[NSUnderlineColorAttributeName] = [UIColor orangeColor];        //设置下划线可见        dic[NSUnderlineStyleAttributeName] = @YES;        //设置字体        dic[NSFontAttributeName] = [UIFont systemFontOfSize:12];        //设置字体颜色        dic[NSForegroundColorAttributeName] = [UIColor orangeColor];        NSAttributedString *title = [[NSAttributedString alloc]initWithString:@"密码登录" attributes:dic];        [_pwdButton setAttributedTitle:title forState:UIControlStateNormal];        [self.view addSubview:_pwdButton];         [_pwdButton mas_makeConstraints:^(MASConstraintMaker *make) {             make.top.equalTo(100);             make.centerX.equalTo(0);             make.height.equalTo(50);             make.width.equalTo(100);         }];        //        [_pwdButton setAttributedTitle:title forState:UIControlStateNormal];        //        [self.view addSubview:_pwdButton];        //        [_pwdButton mas_makeConstraints:^(MASConstraintMaker *make) {        //            make.right.equalTo(-25);        //            make.top.equalTo(self.codeLoginButton.mas_bottom).offset(15);        //        }];    }    return _pwdButton;}

效果如下图：