Question

我有一个包含文字字段的视图。还配置键盘完成按钮以隐藏键盘。我已将代表附加到我的txtfield以在显示键盘时向上滚动。它工作正常，但当我点击完成隐藏键盘时，视图仍然向上滚动，用户必须手动滚动它..任何想法/指针如何解决这个问题..

下面是我的代码，用于实现向上滚动功能..

- (void)viewWillAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    keyboardIsShown = NO;

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification
                                               object:self.view.window];
    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification
                                               object:self.view.window];
}

- (void)viewWillDisappear:(BOOL)animated
{

    [super viewDidDisappear:animated];

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIKeyboardWillShowNotification
                                                  object:nil];

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


- (void)keyboardWillShow:(NSNotification *)n
{
    if (keyboardIsShown) {
        return;
    }

    NSDictionary* userInfo = [n userInfo];

    // get the size of the keyboard
    CGSize keyboardSize = [[userInfo objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    // resize the noteView
    CGRect viewFrame = self.scrollView.frame;
    // I'm also subtracting a constant kTabBarHeight because my UIScrollView was offset by the UITabBar so really only the portion of the keyboard that is leftover pass the UITabBar is obscuring my UIScrollView.
    viewFrame.size.height -= (keyboardSize.height - kTabBarHeight);

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    // The kKeyboardAnimationDuration I am using is 0.3
    [UIView setAnimationDuration:kKeyboardAnimationDuration];
    [self.scrollView setFrame:viewFrame];
    [UIView commitAnimations];

    scrollView.contentSize = formView.frame.size;


    keyboardIsShown = YES;
}

- (void)keyboardWillHide:(NSNotification *)n
{
    NSDictionary* userInfo = [n userInfo];

    // get the size of the keyboard
    CGSize keyboardSize = [[userInfo objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;


    // resize the scrollview
    CGRect viewFrame = self.scrollView.frame;
    // I'm also subtracting a constant kTabBarHeight because my UIScrollView was offset by the UITabBar so really only the portion of the keyboard that is leftover pass the UITabBar is obscuring my UIScrollView.
    viewFrame.size.height += (keyboardSize.height - kTabBarHeight);

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    // The kKeyboardAnimationDuration I am using is 0.3
    [UIView setAnimationDuration:kKeyboardAnimationDuration];
    [self.scrollView setFrame:viewFrame];
    [UIView commitAnimations];

    keyboardIsShown = NO;
}

Answer 1

此apple docs for Text Programming的链接可能很有用。

特别是与this SO question

结合使用时

Answer 2

如果你只想用动画回滚到顶部。

-(void)keyboardWillHide:(NSNotification *)notification {
        UIEdgeInsets contentInsets = UIEdgeInsetsZero;
        CGPoint top = CGPointMake(0, 0);
        [self.scrollView setContentOffset:top animated:YES];
        self.scrollView.scrollIndicatorInsets = contentInsets;
}

上述实现中不需要keyboardIsShown实例变量

Answer 3

试试这个：

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, 216, 0.0);
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
    CGRect frame = CGRectMake(0, textFieds.frame.origin.y + kOtherViewsHeightWhichMightNotBeInSameViewAsScrollView, 10, 10);

    [self.scrollView scrollRectToVisible:frame] animated:YES];
}

- (BOOL)textFieldShouldEndEditing:(UITextField *)textField
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
    return YES;
}

不要忘记将视图控制器设置为文本字段的代理

隐藏键盘时如何向下滚动视图

3 个答案: