UITableView 滚动到错误的位置

Posted 2023-03-11

【中文标题】UITableView 滚动到错误的位置

【英文标题】：UITableView scrolls to wrong position

【发布时间】：2020-02-20 17:13:01

【问题描述】：

我有一个UITableView，我插入了很多单元格。每个单元格包含一个UITextField。我想自动滚动到焦点UITextField。但是如果我删除一个单元格，UITableView 无法滚动到正确的UITextField，键盘与焦点UITextField 重叠

    [super viewDidLoad];
    // Do any additional setup after loading the view.
    [self registerForKeyboardNotifications];
    cellArray = [[NSMutableArray alloc] initWithObjects:_cell0, _cell1, _cell2, _cell3, _cell4, _cell5, _cell6, _cell7, _cell8, _cell9, _cell10, _cell11, _cell12, _cell13, _cell14, _cell15, nil];


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
    return [cellArray count];

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    return [cellArray objectAtIndex:indexPath.row];


- (void)textFieldDidBeginEditing:(UITextField *)textField

    if (textField == _input0) 
        [cellArray removeObject:_cell1];
        [_tableView reloadData];
    
        activeField = textField;


- (void)textFieldDidEndEditing:(UITextField *)textField

    activeField = nil;



- (void)registerForKeyboardNotifications

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillBeHidden:)
                                                 name:UIKeyboardWillHideNotification object:nil];


- (void)keyboardWasShown:(NSNotification*)aNotification

    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;

    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height+100, 0.0);

    _tableView.contentInset = contentInsets;
    _tableView.scrollIndicatorInsets = contentInsets;

    // If active text field is hidden by keyboard, scroll it so it's visible
    // Your app might not need or want this behavior.
    CGRect aRect = self.view.frame;
    aRect.size.height -= kbSize.height;
    if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) 
        [_tableView scrollRectToVisible:activeField.frame animated:YES];
    


- (void)keyboardWillBeHidden:(NSNotification*)aNotification

     UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    _tableView.contentInset = contentInsets;
    _tableView.scrollIndicatorInsets = contentInsets;
```

【问题讨论】：

所以问题是由[cellArray removeObject:_cell1]; [_tableView reloadData];引起的，那不是如何删除单元格。当用户在其中编辑时删除一个单元格有点疯狂。如果你对我这样做，我会删除你的应用程序。

啊，是的，我疯了，谢谢！

【参考方案1】：

// 删除索引路径处的行 [m_tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];

// 在索引路径插入行 [m_tableView insertRowsAtIndexPaths:@[m_indexPath] withRowAnimation:UITableViewRowAnimationFade];