Question

你能看到iPad键盘右下角的按钮吗？

iPad UIKeyboard

我想要访问该按钮的事件处理程序，因为，当我按下特定按钮时，我需要管理一些逻辑。

我尝试过的解决方案包括使用UIKeyboardWillHideNotification通知，如下所示：

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(hideKeyboardTapped:)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];

然而，这被称为每次键盘被解除，包括按下搜索取消按钮，手势点击背景等;所有这些逻辑略有不同。

所以我只需要在按下特定的“隐藏键盘”按钮时有一套逻辑。

UIKeyboard由UISearchBar激活（对于那些需要额外信息的人）。

非常感谢任何帮助;我会回答你的任何问题。

Answer 1

没有官方的，苹果认可的方式来做到这一点。

如果您不介意使用私人课程，可能会让您从App Store拒绝，则会有一种不受支持的方法。基本上，您会听取键盘activeKey属性的更改，如果新的活动键名称为"Dismiss-Key"，则会点击关闭键：

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self)
    {
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
    }
    return self;
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if ([keyPath isEqualToString:@"activeKey"])
    {
        id activeKey = [object valueForKey:keyPath];
        NSString *keyName = [activeKey valueForKey:@"name"];
        if ([keyName isEqualToString:@"Dismiss-Key"])
        {
            [self didTapDismissKey];
        }
    }
    else
    {
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)keyboardDidShow:(NSNotification *)notification
{
    // Search for the UIKeyboardLayoutStar class, which seems to manage layout for the keyboard, and observe its activeKey property
    UIWindow *topWindow = [UIApplication sharedApplication].windows.lastObject;
    [self traverseViewHierarchyWithView:topWindow block:^(UIView *view, BOOL *stop) {

        if ([view isKindOfClass:NSClassFromString(@"UIKeyboardLayoutStar")])
        {
            [view addObserver:self forKeyPath:@"activeKey" options:0 context:NULL];
        }
    }];
}

- (void)keyboardWillHide:(NSNotification *)notification
{
    // Don't forget to remove the controller as an observer!
    UIWindow *topWindow = [UIApplication sharedApplication].windows.lastObject;
    [self traverseViewHierarchyWithView:topWindow block:^(UIView *view, BOOL *stop) {

        if ([view isKindOfClass:NSClassFromString(@"UIKeyboardLayoutStar")])
        {
            [view removeObserver:self forKeyPath:@"activeKey"];
        }
    }];
}

- (BOOL)traverseViewHierarchyWithView:(UIView *)view block:(void (^)(UIView *, BOOL *))block
{
    BOOL stop = NO;
    block(view, &stop);

    if (stop)
    {
        return YES;
    }

    for (UIView *subview in view.subviews)
    {
        if ([self traverseViewHierarchyWithView:subview block:block])
        {
            return YES;
        }
    }

    return NO;
}

- (void)didTapDismissKey
{
    NSLog(@"Dismiss key tapped");
}

在iOS 7 iPad模拟器上测试，它可以正常工作。

Answer 2

我不知道你是否可以把听众放在键盘的一个按钮上，但你可以尝试在视图上设置一些布尔值，这可以打开/关闭你想要的事件或者不要＃ 39;我想处理（我会这样做），例如：

在您所在的班级添加自定义通知观察者/听众想要执行事件的方法。
在将触发通知的控制器上添加Apple默认键盘隐藏侦听器。
然后，在可以触发事件的视图上...设置布尔值以激活/停用事件动作

@Some Other Class

- （无效）viewWillAppear中：（BOOL）动画{

[[NSNotificationCenter defaultCenter]addObserver:self
                                        selector:@selector(doSomething)
                                            name:@"doSomethingNotification"
                                          object:nil];

}

- （无效）viewWillDisappear：（BOOL）动画{

[[NSNotificationCenter defaultCenter] removeObserver:self name:@"doSomethingNotification" object:nil];

}

@Trigger Class

-(void)viewWillAppear:(BOOL)animated{

        self.isNotificationNeeded = NO;
        [[NSNotificationCenter defaultCenter]addObserver:self
                                                selector:@selector(onKeyboardHide:)
                                                    name:UIKeyboardWillHideNotification
                                                  object:nil];
    }

    -(void)viewWillDisappear:(BOOL)animated{

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

    }

    -(void)onKeyboardHide:(id)sender{

        //When your event is Happening
        if (self.isNotificationNeeded == YES) {

            NSNotification *n = [NSNotification notificationWithName:@"doSomethingNotification" object:nil];
            [[NSNotificationCenter defaultCenter] postNotification:n];


            self.isNotificationNeeded = NO;
        }


    }

    -(void)userClickedCancelButton{

        //If this is a keyboard hide event that you don't want to trigger
        self.isNotificationNeeded = NO; 

    }

    //SearchBarDelegate
    -(BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar{

        self.isNotificationNeeded = YES; //If your event can happen from here

        return YES;


    }

iPad UIKeyboard隐藏/退出/关闭按钮事件处理程序？

2 个答案: