获取UITableView以滚动到所选的UITextField并避免被键盘隐藏

Question

我有一个(不是a )UITextField表格视图.如果表格视图位于a上,则表格将自动滚动到正在编辑的页面,以防止它被键盘隐藏.但事实并非如此.UIViewControllerUITableViewControllerUITableViewControllertextFieldUIViewController

我已经尝试了几天阅读多种方法来尝试实现这一点,我无法让它工作.实际滚动的最接近的是:

-(void) textFieldDidBeginEditing:(UITextField *)textField {

// SUPPOSEDLY Scroll to the current text field

CGRect textFieldRect = [textField frame];
[self.wordsTableView scrollRectToVisible:textFieldRect animated:YES];

}

但是,这只会将表格滚动到最顶行.看似简单的任务是几天的挫败感.

我使用以下来构造tableView单元格:

- (UITableViewCell *)tableView:(UITableView *)aTableView
    cellForRowAtIndexPath:(NSIndexPath *)indexPath {

NSString *identifier = [NSString stringWithFormat: @"%d:%d", [indexPath indexAtPosition: 0], [indexPath indexAtPosition:1]];

UITableViewCell *cell = [aTableView dequeueReusableCellWithIdentifier:identifier];

    if (cell == nil) {

        cell = [[[UITableViewCell alloc] 
        initWithStyle:UITableViewCellStyleDefault 
        reuseIdentifier:identifier] autorelease];

        cell.accessoryType = UITableViewCellAccessoryNone;

        UITextField *theTextField = [[UITextField alloc] initWithFrame:CGRectMake(180, 10, 130, 25)];

        theTextField.adjustsFontSizeToFitWidth = YES;
        theTextField.textColor = [UIColor redColor];
        theTextField.text = [textFieldArray objectAtIndex:indexPath.row];
        theTextField.keyboardType = UIKeyboardTypeDefault;
        theTextField.returnKeyType = UIReturnKeyDone;
        theTextField.font = [UIFont boldSystemFontOfSize:14];
        theTextField.backgroundColor = [UIColor whiteColor];
        theTextField.autocorrectionType = UITextAutocorrectionTypeNo;
        theTextField.autocapitalizationType = UITextAutocapitalizationTypeNone;
        theTextField.clearsOnBeginEditing = NO;
        theTextField.textAlignment = UITextAlignmentLeft;

        //theTextField.tag = 0;
        theTextField.tag=indexPath.row;

        theTextField.delegate = self;

        theTextField.clearButtonMode = UITextFieldViewModeWhileEditing;
        [theTextField setEnabled: YES];

        [cell addSubview:theTextField];

        [theTextField release];


}

return cell;
}

我怀疑我能得到的tableView到正常滚动,如果我能以某种方式传递indexPath.row的textFieldDidBeginEditing方法是什么？

任何帮助表示赞赏.

Answer 1

在我的应用程序,我已经成功地使用的组合contentInset和scrollToRowAtIndexPath这样的:

当您想要显示键盘时,只需在底部添加一个contentInset,其中您的表格具有所需的高度:

tableView.contentInset =  UIEdgeInsetsMake(0, 0, height, 0);

然后,您可以安全地使用

[tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:cell_index inSection:cell_section] animated:YES];

通过添加contentInset,即使您专注于最后一个单元格,tableView仍然可以滚动.只需确保在解除键盘时重置contentInset.

编辑:
如果您只有一个部分(可以替换cell_section为0)并使用textView标记来通知单元格行.

在UITableView或UIScrollView中检查此键盘上的Scroll UITextField

Answer 2

- (void)keyboardWillShow:(NSNotification *)sender
{
    CGFloat height = [[sender.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;
    NSTimeInterval duration = [[sender.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationOptions curveOption = [[sender.userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] unsignedIntegerValue] << 16;

    [UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionBeginFromCurrentState|curveOption animations:^{
        UIEdgeInsets edgeInsets = UIEdgeInsetsMake(0, 0, height, 0);
        tableView.contentInset = edgeInsets;
        tableView.scrollIndicatorInsets = edgeInsets;
    } completion:nil];
}

- (void)keyboardWillHide:(NSNotification *)sender
{
    NSTimeInterval duration = [[sender.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationOptions curveOption = [[sender.userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] unsignedIntegerValue] << 16;

    [UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionBeginFromCurrentState|curveOption animations:^{
        UIEdgeInsets edgeInsets = UIEdgeInsetsZero;
        tableView.contentInset = edgeInsets;
        tableView.scrollIndicatorInsets = edgeInsets;
    } completion:nil];
}

并在 - (void)viewDidLoad中

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

然后

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

Answer 3

这是对FunkyKat答案的一个调整(非常感谢FunkyKat!).将UIEdgeInsetsZero硬编码以用于未来的iOS兼容性可能会有所帮助.

相反,我要求当前的插入值并根据需要调整底部值.

- (void)keyboardWillShow:(NSNotification *)sender {
    CGSize kbSize = [[[sender userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
    NSTimeInterval duration = [[[sender userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    CGFloat height = UIDeviceOrientationIsPortrait([[UIDevice currentDevice] orientation]) ? kbSize.height : kbSize.width;
    if (isIOS8()) height = kbSize.height;

    [UIView animateWithDuration:duration animations:^{
        UIEdgeInsets edgeInsets = [[self tableView] contentInset];
        edgeInsets.bottom = height;
        [[self tableView] setContentInset:edgeInsets];
        edgeInsets = [[self tableView] scrollIndicatorInsets];
        edgeInsets.bottom = height;
        [[self tableView] setScrollIndicatorInsets:edgeInsets];
    }];
}

- (void)keyboardWillHide:(NSNotification *)sender {
    NSTimeInterval duration = [[[sender userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    [UIView animateWithDuration:duration animations:^{
        UIEdgeInsets edgeInsets = [[self tableView] contentInset];
        edgeInsets.bottom = 0;
        [[self tableView] setContentInset:edgeInsets];
        edgeInsets = [[self tableView] scrollIndicatorInsets];
        edgeInsets.bottom = 0;
        [[self tableView] setScrollIndicatorInsets:edgeInsets];
    }];
}

Answer 4

为了遇到这个问题的其他人,我在这里发布了必要的方法:

- (UITableViewCell *)tableView:(UITableView *)aTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    NSString *identifier = [NSString stringWithFormat: @"%d:%d", [indexPath indexAtPosition: 0], [indexPath indexAtPosition:1]];

    UITableViewCell *cell = [aTableView dequeueReusableCellWithIdentifier:identifier];

    if (cell == nil) {

        cell = [[[UITableViewCell alloc]  initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier] autorelease];

        UITextField *theTextField = [[UITextField alloc] initWithFrame:CGRectMake(180, 10, 130, 25)];

        theTextField.keyboardType = UIKeyboardTypeDefault;
        theTextField.returnKeyType = UIReturnKeyDone;
        theTextField.clearsOnBeginEditing = NO;
        theTextField.textAlignment = UITextAlignmentLeft;

        // (The tag by indexPath.row is the critical part to identifying the appropriate
        // row in textFieldDidBeginEditing and textFieldShouldEndEditing below:)

        theTextField.tag=indexPath.row;

        theTextField.delegate = self;

        theTextField.clearButtonMode = UITextFieldViewModeWhileEditing;
        [theTextField setEnabled: YES];

        [cell addSubview:theTextField];

        [theTextField release];

    }

    return cell;
}

-(void) textFieldDidBeginEditing:(UITextField *)textField {

    int z = textField.tag;                                              

    if (z > 4) {

        // Only deal with the table row if the row index is 5 
        // or greater since the first five rows are already 
        // visible above the keyboard   

        // resize the UITableView to fit above the keyboard

        self.wordsTableView.frame = CGRectMake(0.0,44.0,320.0,200.0);       

        // adjust the contentInset

        wordsTableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 10);        

        // Scroll to the current text field

        [wordsTableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:z inSection:0] atScrollPosition:UITableViewScrollPositionBottom animated:YES];

    }
}


- (BOOL)textFieldShouldEndEditing:(UITextField *)textField {

    // Determine which row is being edited

    int z = textField.tag;  

    if (z > 4) {

        // resize the UITableView to the original size

        self.wordsTableView.frame = CGRectMake(0.0,44.0,320.0,416.0);       

        // Undo the contentInset
        wordsTableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0);         

    }

    return YES;

}

- (BOOL)textFieldShouldReturn:(UITextField *)textField {

    // Dismisses the keyboard when the "Done" button is clicked

    [textField resignFirstResponder];

    return YES;                                 

}