Question

我正在开发一个聊天应用程序，其中我有一个textview（而不是textfield），当我点击它时，键盘应该显示，一切都应该向上移动。

到目前为止，我已设法将表格视图和textview的框架向上移动并使用以下代码显示键盘。

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

    NSDictionary* info = [notification userInfo];

    keyboardSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    CGPoint contentViewOrigin = self.contentView.frame.origin;

    CGFloat contentViewHeight = self.contentView.frame.size.height;

    CGRect visibleRect = self.view.frame;

    visibleRect.size.height -= keyboardSize.height;
    BOOL up = CGRectContainsPoint(visibleRect, contentViewOrigin);

    if (!up){


    self.tableView.frame = CGRectMake(self.tableView.frame.origin.x,self.tableView.frame.origin.y,self.tableView.frame.size.width,280.0f);


    self.contentView.frame = CGRectOffset(self.contentView.frame, 0, 0 - keyboardSize.height);

    if([self.tableView numberOfRowsInSection:0]!=0)
    {
        NSIndexPath* ip = [NSIndexPath indexPathForRow:[self.tableView numberOfRowsInSection:0]-1 inSection:0];
        [self.tableView scrollToRowAtIndexPath:ip atScrollPosition:UITableViewScrollPositionBottom animated:UITableViewRowAnimationLeft];
    }


}

}

- (void)keyboardWillBeHidden:(NSNotification *)notification {

self.contentView.frame = originalContentView;
self.tableView.frame = originalTable;
}


- (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)deregisterFromKeyboardNotifications {

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

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

}

但是当我看到whatsapp如何做到这一点时，我的看起来就像一个黑客。 Whatsapp的键盘与所有元素一起向上移动，而我的工作方式如下：首先显示键盘，向应用程序发送通知，收到通知，代码计算键盘高度并根据高度向上移动元素。

我搜索并找到了我已实施的解决方案。

有人可以帮忙吗？

Answer 1

我在我的应用程序中经常使用这个技巧。您想收听UIKeyboardWillShowNotification和UIKeyboardWillHideNotification。在我看来，处理动画的最佳方法是使用autolayout。当你调用[self.view layoutIfNeeded]时;您的视图将随键盘动画一起移动。不需要动画块。

我为任何人设置了一个简单的project，试着看看它是如何运作的！

- (void)addKeyboardNotificationsObserver {

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

}

- (void)handleKeyboardWillShow:(NSNotification *)paramNotification

{

    NSDictionary* info = [paramNotification userInfo];

    //when switching languages keyboard might change its height (emoji keyboard is higher than most keyboards). 
    //You can get both sizes of the previous keyboard and the new one from info dictionary. 

    // size of the keyb that is about to disappear
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    // size of the keyb that is about to appear
    CGSize kbSizeNew = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;

    //make adjustments to constraints here...

    //and here where's magick happen!

    [self.view layoutIfNeeded];

}

- (void)handleKeyboardWillHide:(NSNotification *)paramNotification

{
    //adjust constraints

    [self.view layoutIfNeeded];

}

Answer 2

您可以使用UIKeyboardWillShowNotification和UIKeyboardWillHideNotification
从这里尝试TPKeyboardAvoidingScrollView：https://github.com/michaeltyson/TPKeyboardAvoiding（我的选择）

iOS键盘显示事件处理

2 个答案: