微信聊天

1.要用到MVC代理模式

2.要根据消息内容计算单元格的高度

3.在输入框中输入内容添加到单元格上去

controller

//加载数据 NSString *filePath = [[NSBundle mainBundle] pathForResource:@"messages.plist" ofType:nil];        NSArray *array = [NSArray arrayWithContentsOfFile:filePath];        _data = [[NSMutableArray array] retain];        //将数据存储到model中    for (NSDictionary *dic in array) {                //创建model对象,将字典中的数据存储到model中        Message *message = [[Message alloc] init];        message.content = [dic objectForKey:@"content"];        message.icon = [dic objectForKey:@"icon"];        message.isSelf = [[dic objectForKey:@"self"] boolValue];        message.time = [dic objectForKey:@"time"];        

 //将message对象放在数组中        //一个message对象代表一条消息        [_data addObject:message];                    }

//创建tableView视图和textField输入框 _tabelView.separatorStyle = UITableViewCellSeparatorStyleNone;            //将键盘上的return按钮改为send    _inputView.returnKeyType = UIReturnKeySend;        _inputView.delegate = self;- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {    return _data.count;    }- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {    static NSString *intenty = @"UITableViewCell";        MessageCell *cell = [tableView dequeueReusableCellWithIdentifier:intenty];    if (cell == nil) {                cell = [[MessageCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:intenty];    }        Message *message =  _data[indexPath.row];        //将model交给视图去显示    [cell setMessage:message];        return cell;}

<pre name="code" class="objc">//返回单元格高度- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{        //取到message对象,计算高度    Message *message = _data[indexPath.row];    CGSize size = [message.content sizeWithFont:[UIFont systemFontOfSize:16] constrainedToSize:CGSizeMake(220, 9999) lineBreakMode:NSLineBreakByWordWrapping];        return size.height + 40;    }

<span style="font-size:32px;"></span>

<span style="font-size:32px;">View</span><span style="color:#003333;">//cell布局，赋值UIImage *image = [UIImage imageNamed:_message.icon]; //用户头像        userimage.image = image;//2.计算聊天信息所占用的空间大小    //此方法会显示警告,因为此方法在ios7中已不建议使用(但仍可以使用)    CGSize size = [_message.content sizeWithFont:[UIFont systemFontOfSize:16] constrainedToSize:CGSizeMake(220, 9999) lineBreakMode:NSLineBreakByWordWrapping];    //3.根据求得的大小设置lable的高度    _lable.text = _message.content;        //背景视图    UIImage *img1 = [UIImage imageNamed:@"chatfrom_bg_normal.png"]; //绿色背景    UIImage *img2 = [UIImage imageNamed:@"chatto_bg_normal.png"];  //白色 自己        UIImage *bgImg = _message.isSelf ?img2:img1;            bgImg = [bgImg stretchableImageWithLeftCapWidth:bgImg.size.width * .5 topCapHeight:bgImg.size.height * .7];        _bgImage.image = bgImg;            //布局子视图 需判断消息是否为自己发送    if (_message.isSelf) {                userimage.frame = CGRectMake(320 - 50, 10, 40, 40);        _bgImage.frame = CGRectMake(20, 10, size.width + 30, size.height + 30);        _lable.frame = CGRectMake(40, 20, size.width, size.height);            }else{            userimage.frame = CGRectMake(10, 10, 40, 40);        _bgImage.frame = CGRectMake(60, 10, size.width + 30, size.height + 30);        _lable.frame = CGRectMake(75, 20, size.width, size.height);        }</span>

最后

<p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><pre name="code" class="objc"><pre name="code" class="objc">//send按钮被点击时,调用的方法- (BOOL)textFieldShouldReturn:(UITextField *)textField {    //1.获取用户输入的内容    NSString *text = textField.text;        //2.创建一个message对象    Message *message = [[Message alloc] init];    message.content = text;    message.icon = @"icon01.jpg";    message.isSelf = YES;        //将message对象放入数组中    [_data addObject:message];    //    //刷新表视图//    [_tabelView reloadData];        //取得最后一个单元格的下标    NSInteger index =  _data.count - 1;    NSIndexPath*indexPath = [NSIndexPath indexPathForRow:index inSection:0];        //在表视图的最后插入一个单元格    [_tabelView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationRight];        //滚动到最后一个单元格    [_tabelView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];        //将输入框设为空    _inputView.text = nil;        return YES;}