iOS 实现隐藏系统键盘

实现隐藏系统键盘，显示自定义键盘吧；

UITextfield获取焦点时，进入textFieldShouldBeginEditing方法，在这个方法中注册两个通知：

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

//隐藏系统键盘

- (void)keyboardWillShow:(NSNotification *)Notification{
    UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
    [tempWindow setAlpha:0];
}

//显示自定义键盘

- (void)keyboardWasShown:(NSNotification *) Notification{
// 添加显示你的自定义键盘 }