Question

我有一个UISearchBar。现在当我点击搜索栏时，键盘出现了。

我需要在键盘出现之前做点什么。我的布局发生了变化。

那么在键盘显示之前有什么方法可以做某事吗？

我想也许是这样，但它不起作用：

-(BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar
{
    [_searchBar resignFirstResponder];

    return YES;
}

但键盘并没有隐藏。

有任何建议吗？

Answer 1

您可以在返回YES或NO之前在searchBarShouldBeginEditing中执行UI更改。如果您不想显示键盘返回NO。

-(BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar
{
   // Do the changes in UI

    return YES;
}

Answer 2

您可以使用NSNotificationCenter在键盘显示和隐藏时收到通知。

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

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

然后添加将被调用的两个方法：

- (void)onKeyboardWillShow:(NSNotification *)notification
{   
    NSLog(@"Keyboard will show!");
}

- (void)onKeyboardWillHide:(NSNotification *)notification
{
    NSLog(@"Keyboard will hide!");
}

离开视野时不要忘记停止听：

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

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

Answer 3

如果你想隐藏键盘：

上仅使用此viewwillAppear方法

[searchBarObje resignFirstResponsder];

您只需致电：以显示

[searchBarObje becomeFirstResponsder];

or you can use 
-(BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar
{
   // Do the changes in UI
   [searchBar becomeFirstResponsder];
    return YES;
}

我想。，这会对你有帮助。

Answer 4

您可以使用以下标准iOS通知执行此操作：

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

UISearchbar在键盘出现之前做了一些事情

4 个答案: