iOS8 : 当键盘出现并按下后退按钮时，此时下一个视图出现很慢

Question

我有 ViewController (v2) 和 UITextView 。我从 viewController (V1) 推送了那个视图。在 V2 上，当我点击 textview 时，键盘会出现，然后点击后退按钮并继续 V1。我重复此过程 15 到 20 次，发现我的应用程序的性能变得非常慢。

问题是当我点击后退按钮时键盘需要很长时间才能消失：

我正在使用以下代码行：

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

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

}

- (IBAction)back:(id)sender
{
    [self.navigationController popViewControllerAnimated:NO];
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    [noteView becomeFirstResponder];
}

- (void)viewWillDisappear:(BOOL)animated {

    [noteView resignFirstResponder];

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

    [super viewWillDisappear:animated];
 }

- (void)willShowKeyboard:(NSNotification *)notification
{
    [UIView setAnimationsEnabled:NO];
}
- (void)keyboardWillHide:(NSNotification *)notification
{
    [UIView setAnimationsEnabled:NO];
}

- (void)keyboardDidHide:(NSNotification *)notification
{
    [UIView setAnimationsEnabled:NO];
}

Answer 1

当用户按下后退按钮时，只需一行代码即可关闭键盘

- (IBAction)back:(id)sender
{
    [self.view endEditing:YES];
    [self.navigationController popViewControllerAnimated:NO];
}

iOS8 : 当键盘出现并按下后退按钮时，此时下一个视图出现很慢

iOS8 : When Keyboard appear and press Back button, at that time next view appear very slow

keyboard

popviewcontroller

ios8