ios - didMoveToParentViewController调用了两次

我做了一个简单的测试，以了解有关包含 View Controller 的更多信息。
我有一个 View Controller ，使用两个按钮的 Action 在其中添加/删除了 View Controller :

- (IBAction)myInfoAddAction:(id)sender {
    profileViewController = [[ProfileViewController alloc] init];
    [self addChildViewController: profileViewController];
    UIView *__view = profileViewController.view;
    [self.view addSubview: __view];
    [profileViewController didMoveToParentViewController: self];
}

- (IBAction)myInfoRemoveAction:(id)sender {
    [profileViewController willMoveToParentViewController: nil];
    [profileViewController.view removeFromSuperview];
    [profileViewController removeFromParentViewController];
}

ProfileViewController类扩展了UIViewController并覆盖了willMoveToParentViewController和didMoveToParentViewController方法

-( void)willMoveToParentViewController:(UIViewController *)parent
{
    [super willMoveToParentViewController: parent];
    NSLog(@"willMoveToParentViewController -> %@", self);
}

-( void) didMoveToParentViewController:(UIViewController *)parent
{
    [super didMoveToParentViewController: parent];
    NSLog(@"didMoveToParentViewController -> %@", self);
}

-( void)viewWillAppear:(BOOL)animated
{
    NSLog(@"viewWillAppear -> %@", self);
}

-( void)viewDidDisappear:(BOOL)animated
{
    NSLog(@"viewDidDisappear -> %@", self);
}

当添加 View Controller 时，得到以下日志:

willMoveToParentViewController -> <ProfileViewController: 0x8c52ea0>
viewWillAppear -> <ProfileViewController: 0x8c52ea0>
didMoveToParentViewController -> <ProfileViewController: 0x8c52ea0>
didMoveToParentViewController -> <ProfileViewController: 0x8c52ea0>

当我删除 View Controller 时:

willMoveToParentViewController -> <ProfileViewController: 0x8c52ea0>
didMoveToParentViewController -> <ProfileViewController: 0x8c52ea0>
viewDidDisappear -> <ProfileViewController: 0x8c52ea0>
didMoveToParentViewController -> <ProfileViewController: 0x8c52ea0>

我想知道为什么didMoveToParentViewController被调用两次？

谢谢!

最佳答案

我也遇到过同样的问题。此外，我发现在viewDidLoad期间添加 subview Controller 时，只有一条消息。我通过删除对[super didMoveToParentViewController:]的调用来解决此问题。我认为问题与在通过按钮进行回调时添加 subview Controller 有关，但是我不确定为什么这会引起问题。

关于ios - didMoveToParentViewController调用了两次，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/18313888/