UILabel * countentLable = [[UILabel alloc]initWithFrame:CGRectMake(100, 100, 100, 20)];
countentLable.font = [UIFont systemFontOfSize:10];
NSString * CommentStr = @"10楼的回复（23条）";
NSMutableAttributedString * attributeStr = [[NSMutableAttributedStringalloc]initWithString:CommentStr];
NSRange colorFondRange = NSMakeRange([[contentStr string] rangeOfString:@"（23条）"].location, [[attributeStr string] rangeOfString@"（23条）"].length);
//[CommentStr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:colorFondRange];如果只需修改颜色就用这个
//[CommentStr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:25] range:colorFondRange];如果只需修改大小就用这个
[countentLable setAttributedText:CommentStr];
[self.view addSubview:countentLable];