经过大量的试验和错误,我放弃了,并提出了这个问题。我见过很多人有类似的问题,但不能得到所有的答案工作正确。

我有一个由自定义单元格组成的UITableView。单元格由相邻的5个文本字段组成(有点像网格)。

当我试图滚动和编辑UITableView底部的单元格时,我不能设法让我的单元格正确地定位在键盘上方。

我看到过很多关于改变视图大小的回答……但到目前为止,没有一种效果很好。

谁能用一个具体的代码示例来阐明这样做的“正确”方式?


当前回答

如果你使用uitableview来放置你的文本字段(来自Jeff Lamarche),你可以像这样使用委托方法滚动tableview。

(注意:我的文本字段存储在一个数组中,索引与表视图中的行相同)

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

        int index;
        for(UITextField *aField in textFields){

            if (textField == aField){
                index = [textFields indexOfObject:aField]-1;
            }
        }

         if(index >= 0) 
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:index inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:YES];

        [super textFieldDidBeginEditing:textField];
    }

其他回答

看看我的版本:)

    - (void)keyboardWasShown:(NSNotification *)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    CGRect bkgndRect = cellSelected.superview.frame;
    bkgndRect.size.height += kbSize.height;
    [cellSelected.superview setFrame:bkgndRect];
    [tableView setContentOffset:CGPointMake(0.0, cellSelected.frame.origin.y-kbSize.height) animated:YES];
}


- (void)keyboardWasHidden:(NSNotification *)aNotification
{
    [tableView setContentOffset:CGPointMake(0.0, 0.0) animated:YES];
}

Swift 4.2的小变化…

在我的UITableView上,我有很多部分,但我必须避免浮动标题效果,所以我使用了“dummyViewHeight”方法,就像在Stack Overflow上看到的其他地方一样… 这就是我对这个问题的解决方案(它也适用于键盘+工具栏+建议):

将其声明为类常量:

let dummyViewHeight: CGFloat = 40.0

Then

override func viewDidLoad() {
    super.viewDidLoad()
    //... some stuff here, not needed for this example

    // Create non floating header
    tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: tableView.bounds.size.width, height: dummyViewHeight))
    tableView.contentInset = UIEdgeInsets(top: -dummyViewHeight, left: 0, bottom: 0, right: 0)

    addObservers()
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    removeObservers()
}

这里所有的魔法……

@objc func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue.size.height
        tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: self.tableView.bounds.size.width, height: dummyViewHeight))
        tableView.contentInset = UIEdgeInsets(top: -dummyViewHeight, left: 0, bottom: keyboardHeight, right: 0)
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.25) {
        self.tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: self.tableView.bounds.size.width, height: self.dummyViewHeight))
        self.tableView.contentInset = UIEdgeInsets(top: -self.dummyViewHeight, left: 0, bottom: 0, right: 0)
    }
}

我的方法:

我首先子类化UITextField并添加一个indexPath属性。在牢房里因为…方法我交出indexPath属性。

然后我添加以下代码:

UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:textField.indexPath];

CGPoint cellPoint = [cell convertPoint:textField.center toView:self.tableView];
[UIView animateWithDuration:0.3 animations:^(void){self.tableView.contentOffset = CGPointMake(0, cellPoint.y-50);}];

textFieldShould/WillBegin…等等。

当键盘消失时,你必须反转它:

[UIView animateWithDuration:0.3 animations:^(void){self.tableView.contentOffset = CGPointMake(0, 0);}];

以下是我的解决方案,灵感来自iOS7日历应用程序的“事件编辑”屏幕。

该解决方案的关键之一是当用户滚动表格时键盘被取消。

实现:

1)添加属性,将存储选定的文本字段:

@property (strong) UITextField *currentTextField;

和BOOL变量,我们将使用它来检查当用户滚动表时是否需要隐藏键盘。

BOOL hideKeyboardOnScroll;

2)处理UITextField委托回调:

#pragma mark - UITextFieldDelegate

- (void) textFieldDidBeginEditing: (UITextField *) textField {
    self.currentTextField = textField;
}

- (void) textFieldDidEndEditing: (UITextField *) textField {
    self.currentTextField = nil;
}

- (BOOL) textFieldShouldReturn: (UITextField *) textField {
   [textField resignFirstResponder];

    CGPoint newContentOffset = CGPointZero;
    if (tableView.contentSize.height > tableView.frame.size.height) {
        newContentOffset.y = MIN(tableView.contentOffset.y, tableView.contentSize.height - tableView.frame.size.height);
    }
    [tableView setContentOffset: newContentOffset animated: YES];

    return YES;
}

3)处理UIScrollViewDelegate方法来检查用户滚动视图。

#pragma mark - UIScrollViewDelegate

- (void) scrollViewDidScroll: (UIScrollView *) scrollView {
    if (hideKeyboardOnScroll == YES) {
        [self.currentTextField resignFirstResponder];
    }
}

4)在视图控制器的[viewWillAppear]方法中订阅键盘通知,并在[viewWillDisappear]方法中取消订阅。

- (void) viewWillAppear: (BOOL) animated {
    [super viewWillAppear: animated];

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

- (void) viewWillDisappear: (BOOL) animated {
    [super viewWillDisappear: animated];

    [ [NSNotificationCenter defaultCenter] removeObserver: self name: UIKeyboardDidShowNotification object: nil];
    [ [NSNotificationCenter defaultCenter] removeObserver: self name: UIKeyboardWillHideNotification object: nil];    
}

5)处理键盘通知:

- (void) keyboardWillShow: (NSNotification *) notification {
    CGRect keyboardFrame = [ [ [notification userInfo] objectForKey: UIKeyboardFrameBeginUserInfoKey] CGRectValue];

    // Find cell with textfield.
    CGRect textFieldFrame = [tableView convertRect: self.currentTextField.frame fromView: self.currentTextField];
    NSIndexPath *indexPath = [tableView indexPathForRowAtPoint: textFieldFrame.origin];
    UITableViewCell *cell = [tableView cellForRowAtIndexPath: indexPath];
    //

    // Shrink tableView size.
    CGRect tableViewFrame = tableView.frame;
    tableView.frame = CGRectMake(tableView.frame.origin.x, tableView.frame.origin.y, tableView.frame.size.width,
                             self.view.frame.size.height - tableView.frame.origin.y - keyboardFrame.size.height);
    //

    // Check if cell is visible in shrinked table size.
    BOOL cellIsFullyVisible = YES;
    if ( cell.frame.origin.y < tableView.contentOffset.y ||
        (cell.frame.origin.y + cell.frame.size.height) > (tableView.contentOffset.y + tableView.frame.size.height) ) {
        cellIsFullyVisible = NO;
    }
    //

    // If cell is not fully visible when scroll table to show cell;
    if (cellIsFullyVisible == NO) {
        CGPoint contentOffset = CGPointMake(tableView.contentOffset.x, CGRectGetMaxY(cell.frame) - tableView.frame.size.height);
        if (cell.frame.origin.y < tableView.contentOffset.y) {
            contentOffset.y = cell.frame.origin.y;
        }
        contentOffset.y = MAX(0, contentOffset.y);

        // For some reason [setContentOffset] is called without delay then
        // this code may not work for some cells. That why we call it with brief delay.
        dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC));
        dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
            [UIView animateWithDuration: 0.5 animations:^{
                [tableView setContentOffset: contentOffset animated: NO];
            } completion: ^(BOOL finished) {
                hideKeyboardOnScroll = YES;
            }];
        });
    } else {
        hideKeyboardOnScroll = YES;
    }
    //

    // Finally restore original table frame.
    tableView.frame = tableViewFrame;
    //
}

- (void) keyboardWillHide: (NSNotification *) notification {
    [super keyboardWillHide: notification];

    hideKeyboardOnScroll = NO;
}

基于bartjomiej semazynk解决方案的Swift 3最简单的解决方案:

override func viewDidLoad() {
    super.viewDidLoad()

    NotificationCenter.default.addObserver(self, selector: #selector(CreateEditRitualViewController.keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(CreateEditRitualViewController.keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardDidHide, object: nil)
}

deinit {
    NotificationCenter.default.removeObserver(self)
}

// MARK: Keyboard Notifications

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardHeight = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.height {
        tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardHeight, 0)
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.2, animations: {
        // For some reason adding inset in keyboardWillShow is animated by itself but removing is not, that's why we have to use animateWithDuration here
        self.tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0)
    })
}