如何让自定义 UITableView 自动滚动到选定的文本字段？

Question

我有一个UITableView，我通过自定义UIViewController 控制它。当用户单击“添加”按钮时，我向UITableView 添加一行，其中包含一个文本字段，并使其成为第一响应者。问题是，当表格底部不可见（或被键盘隐藏）时，UITableView 不会滚动以显示文本字段。

UITableViewController 自动执行此操作，但我的视图控制器不能是 UITableViewController 的子类。

Answer 1

当键盘出现或消失时，我通过在 UITableView 上旋转 contentInset 来解决此问题。

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

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasHidden:)
                                                 name:UIKeyboardDidHideNotification object:nil];
}

- (void)keyboardWasShown:(NSNotification *)aNotification {
    CGRect keyboardBounds;
    [[aNotification.userInfo valueForKey:UIKeyboardBoundsUserInfoKey] getValue: &keyboardBounds];
    keyboardHeight = keyboardBounds.size.height;
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationBeginsFromCurrentState:YES];
    tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardBounds.size.height, 0);
    [UIView commitAnimations];
    [tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:[items count] inSection:0]
                     atScrollPosition:UITableViewScrollPositionMiddle
                             animated:YES];
}

- (void)keyboardWasHidden:(NSNotification *)aNotification {
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationBeginsFromCurrentState:YES];
    tableView.contentInset = UIEdgeInsetsZero;
    [UIView commitAnimations];
}

在加载UITableView 时调用registerForKeyboardNotifications，其他一切都应该正常工作。

Answer 2

我找到了-scrollToRowAtIndexPath:atScrollPosition:animated:，我猜这会满足你的要求。

Answer 3

我遇到了类似的问题，这是我的解决方案：http://www.passiondeveloper.com/discussion/8/uitableview-inline-editing-with-a-textfield-inside-uitableview-not-scrolling-when-keyboard-is-shown

Answer 4

为 ios5 工作

UITextField *activeField;

// Called when the UIKeyboardDidShowNotification is sent.

-(void)textFieldDidBeginEditing:(UITextField *)textField
{
   activeField = textField;
}
- (void)textFieldDidEndEditing:(UITextField *)textField
{
   activeField = nil;
}

// Called when the UIKeyboardWillHideNotification is sent

- (void)keyboardWasShown:(NSNotification *)aNotification {


   id view = [activeField superview];
   while (view && ![view isKindOfClass:[UITableViewCell class]]) 
   {
      view = [view superview];
   }
   UITableViewCell *cell = view;
   NSIndexPath *indexPath = [tableview indexPathForCell:cell];
   CGRect keyboardBounds;
   [[aNotification.userInfo valueForKey:UIKeyboardBoundsUserInfoKey] getValue: &keyboardBounds];
   [UIView beginAnimations:nil context:nil];
   [UIView setAnimationBeginsFromCurrentState:YES];
   tableview.contentInset = UIEdgeInsetsMake(0, 0, keyboardBounds.size.height, 0);
   [UIView commitAnimations];
   [tableview scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];

}

- (void)keyboardWasHidden:(NSNotification *)aNotification {
   [UIView beginAnimations:nil context:nil];
   [UIView setAnimationBeginsFromCurrentState:YES];
    tableview.contentInset = UIEdgeInsetsZero;
   [UIView commitAnimations];
}