objective-c - 如何以编程方式找出按下的键盘向下箭头键

Question

我知道当在键盘上按下向下箭头键时，我们可以获得键盘隐藏通知，但问题是，当我们旋转设备和键盘隐藏时，我们也会收到键盘隐藏通知，现在如何区分由于按下键而隐藏的键盘不是因为旋转。

Answer 1

在你的 AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
      [[NSNotificationCenter defaultCenter] 
      addObserver:self selector:@selector(keyboardWillHide) 
      name:UIKeyboardWillHideNotification object:nil];
      return YES;
}


-(void) keyboardWillHide {
  NSLog(@"Bye");
}

Answer 2

当我们点击of时，会自动调用以下Delegate方法。textfieldreturn or arrow buttonkeyboard

- (BOOL)textFieldShouldReturn:(UITextField *)textField