实现汽泡聊天，动态计算高度和重新布局可以有在cell中实现，封装起来

来源：互联网发布：ubuntu g 升级编辑：程序博客网时间：2024/05/21 07:00

 1. (void)dealloc{    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];} 2. (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view.    _chatView = [[UIView alloc] initWithFrame:CGRectMake(0, 440, 320, 40)];    _chatView.backgroundColor = [UIColor grayColor];    [self.view addSubview:_chatView];    UITextField * f = [[UITextField alloc] initWithFrame:CGRectMake(20, 5, 240, 30)];    f.tag = 10;    f.borderStyle = UITextBorderStyleRoundedRect;    [_chatView addSubview:f];    UIButton * b = [UIButton buttonWithType:UIButtonTypeSystem];    [b setTitle:@"发送" forState:UIControlStateNormal];    [b addTarget:self action:@selector(send) forControlEvents:UIControlEventTouchUpInside];    b.frame = CGRectMake(270,5,40,30);    [_chatView addSubview:b];

当键盘即将抬起时触发当前对象中的keyboardWillShow方法

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];

// 必须在delloc中移除观察者身份

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHidden:) name:UIKeyboardWillHideNotification object:nil];_tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, 320, 480-40) style:UITableViewStylePlain];_tableView.delegate = self;_tableView.dataSource = self;

// 去掉分割线========    _tableView.separatorStyle = UITableViewCellSeparatorStyleNone;    [self.view addSubview:_tableView];

_dataArr = [NSMutableArray array];[self.view bringSubviewToFront:_chatView];UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap)];[self.view addGestureRecognizer:tap];

}

(void)tap
{
[self.view endEditing:YES];
}
(void)send
{
UITextField * f = (UITextField *)[_chatView viewWithTag:10];
[_dataArr addObject:f.text];
[_tableView reloadData];

// 滚动到最后一行

[_tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:_dataArr.count-1 inSection:0] atScrollPosition:UITableViewScrollPositionBottom animated:YES];

}

(void)keyboardWillShow:(id)note
{
CGFloat height = [[[note userInfo] objectForKey:@”UIKeyboardFrameEndUserInfoKey”] CGRectValue].size.height;

// 动画调整_chatView的位置与键盘同步

[UIView animateWithDuration:0.25 animations:^{    _chatView.frame = CGRectMake(0, 480-height-40, 320, 40);}];

}

(void)keyboardWillHidden:(NSNotification *)note
{
[UIView animateWithDuration:0.25 animations:^{
_chatView.frame = CGRectMake(0, 480-40, 320, 40);
}];
}

pragma mark - UITableViewDataSource

(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return _dataArr.count;
}
(UITableViewCell )tableView:(UITableView )tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString * cellId = @”cellID”;
TableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:cellId];
if (cell == nil) {
cell = [[TableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellId];
}
cell.content = _dataArr[indexPath.row];
cell.contentView.backgroundColor = [UIColor colorWithRed:211/255.0 green:219/255.0 blue:239/255.0 alpha:1.0];
return cell;
}

// 气泡的高度必须根据文字的内容高度+20

(CGFloat)tableView:(UITableView )tableView heightForRowAtIndexPath:(NSIndexPath )indexPath
{
NSString * str = _dataArr[indexPath.row];
return [str sizeWithFont:[UIFont systemFontOfSize:17] constrainedToSize:CGSizeMake(250, 2000)].height+20;
}
“`

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