ios - UIKeyboardWillShow 来自其他应用程序的通知

Question

我的应用程序使用 UIKeyboardWillShow 和 UIKeyboardWillHide 通知监视键盘的变化以动画化 UI 的特定部分。

我遇到的问题是，当我使用应用程序切换器(在不需要键盘的状态下)从显示键盘的消息应用程序切换到我的应用程序时，它将触发 UIKeyboardWillShow 通知，然后是 UIKeyboardWillHide 通知，这导致我的 UI 稍微上下跳动。

有没有办法只为您自己的应用监听键盘通知？

ViewWillAppear

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillChange:", name: UIKeyboardWillChangeFrameNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)

ViewWillDisappear

    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillChangeFrameNotification, object: nil)

Answer 1

有代码吗？ 您是在整个应用程序中还是仅在 viewcontroller 中观察键盘？

每当你不想听变化你可以removeObserver

- (void)applicationDidEnterBackground:(UIApplication *)application
{
    [[NSNotificationCenter defaultCenter] removeObserver:yourClass name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:yourClass name:UIKeyboardWillHideNotification object:nil];
}

但是要小心，你需要正确使用NSNotificationCenter。