这个使用uilabel自调节高度发现的问题，代码如下：

 //content label
            
            NSString *contentValue = ((MessageDetailRecord *)[self.entriesArray objectAtIndex:indexPath.row]).content;
            CGFloat width = 0.0f;
            CGSize orignalSize;
            
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
            if ([GeneralInfo getDeviceSystemVer]){
                
                orignalSize = [contentValue sizeWithAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:20.0f]}];
                width = orignalSize.width;
                
            }else{
                width =  [contentValue sizeWithFont:[UIFont systemFontOfSize:20.0f ]].width;
                
            }
#pragma clang diagnostic pop
            
            //set the most large width
            if (width > cell.frame.size.width - 90.0f) {
                
                width = cell.frame.size.width - 90.0f;
            }

UILabel *content = [[UILabel alloc]initWithFrame:CGRectMake(0.0f, 0.0f, width, 0.0f)];
            self.messageContentLabel = content;
            self.messageContentLabel.font = [UIFont systemFontOfSize:20.0];
            self.messageContentLabel.backgroundColor = [UIColor clearColor];
            self.messageContentLabel.numberOfLines = 0;
            self.messageContentLabel.adjustsFontSizeToFitWidth = YES;
            self.messageContentLabel.lineBreakMode = NSLineBreakByWordWrapping;
            self.messageContentLabel.backgroundColor = [UIColor colorWithRed:241/255.0f green:241/255.0f blue:241/255.0f alpha:1.0];
            CGRect labelFrameContent = self.messageContentLabel.frame;
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
            
            if ([GeneralInfo getDeviceSystemVer]) {
                NSDictionary *stringAttributes = [NSDictionary dictionaryWithObject:self.messageContentLabel.font forKey: NSFontAttributeName];
                
                labelFrameContent.size = [contentValue boundingRectWithSize:CGSizeMake(width, CGFLOAT_MAX)
                                                                    options:NSStringDrawingTruncatesLastVisibleLine|NSStringDrawingUsesLineFragmentOrigin
                                                                 attributes:stringAttributes context:nil].size;
            }else{
                
                labelFrameContent.size = [contentValue sizeWithFont:self.messageContentLabel.font
                                                  constrainedToSize:CGSizeMake(width, CGFLOAT_MAX)
                                                      lineBreakMode:self.messageContentLabel.lineBreakMode];
            }
#pragma clang diagnostic pop
            
            //adjust the height
            if (labelFrameContent.size.height < 50.0f) {
                
                labelFrameContent.size.height = 50.0f;
            }
            
            labelFrameContent.size.width += 10.0f;
            if (labelFrameContent.size.width > cell.frame.size.width - 90.0f) {
                
                labelFrameContent.size.width = cell.frame.size.width - 90.0f;
            }
            
            labelFrameContent.origin.x = 70.0f;
            labelFrameContent.origin.y = self.cellDateLabel.frame.size.height + 10.0f;
            self.messageContentLabel.frame = labelFrameContent;
            [cell.contentView addSubview:self.messageContentLabel];

解决方法是使用uitextview来替换即可

UITextView *content = [[UITextView alloc]initWithFrame:CGRectMake(0.0f, 0.0f, width, 0.0f)];
                    self.messageContentLabel = content;
                    [content release];
                    self.messageContentLabel.font = [UIFont systemFontOfSize:16.0f];
                    self.messageContentLabel.backgroundColor = [UIColor clearColor];
                    self.messageContentLabel.scrollEnabled = NO;
                    self.messageContentLabel.userInteractionEnabled = NO;
                    //self.messageContentLabel.numberOfLines = 0;
                    //self.messageContentLabel.adjustsFontSizeToFitWidth = YES;
                    // self.messageContentLabel.lineBreakMode = NSLineBreakByWordWrapping;
                    self.messageContentLabel.backgroundColor = [UIColor colorWithRed:241/255.0f green:241/255.0f blue:241/255.0f alpha:1.0];
                    self.messageContentLabel.text = contentValue;
                    self.messageContentLabel.textColor = [UIColor grayColor];
                    CGRect labelFrameContent = self.messageContentLabel.frame;
                    
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
                    
                    if ([GeneralInfo getDeviceSystemVer])
                    {
                        labelFrameContent.size = [contentValue boundingRectWithSize:CGSizeMake(width, CGFLOAT_MAX)
                                                                            options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading)
                                                                         attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:17.0f]}
                                                                            context:nil].size;
                    }
                    else
                    {
                        labelFrameContent.size = [contentValue sizeWithFont:self.messageContentLabel.font constrainedToSize:CGSizeMake(width, CGFLOAT_MAX)];
                    }
#pragma clang diagnostic pop

使用uilabel重新自调整高度后显示横线和竖线问题