Question

我正在尝试将视图控制器推到已推送的视图控制器上，如下所示。但是，当我试图推动newPersonViewController时，这个新控制器不会被推入堆栈。我不知道为什么Xcode抱怨我试图添加一个不属于层次结构的新控制器。我是否错误地展示了ABPeoplePickerViewController？这就是newPersonViewController无法被推入堆栈的原因吗？

来自控制台的消息：

警告：尝试显示其视图不在窗口层次结构中！

代码：

- (void)addPerson
{
    ABNewPersonViewController *newPersonVC = [[ABNewPersonViewController alloc] init];
    newPersonVC.newPersonViewDelegate = self;
    UINavigationController *uiNav = [[UINavigationController alloc] initWithRootViewController:newPersonVC];

    [self presentViewController:uiNav animated:YES completion:nil];
}

- (void)showPeoplePicker
{
    ABPeoplePickerNavigationController *picker = [[ABPeoplePickerNavigationController alloc] init];
    picker.peoplePickerDelegate = self;

    [self presentViewController:picker animated:YES completion:nil];
    [picker.topViewController setEditing:YES];
    picker.topViewController.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addPerson)];
    picker.topViewController.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(peoplePickerCancel)];
}

Answer 1

问题是addPerson试图从不是当前控制器的视图控制器模态呈现。 self（您的原始视图控制器）不是活动控制器。 ABPeoplePickerNavigationController是。

首先，定义一个类属性来跟踪picker：

@property (nonatomic, weak) ABPeoplePickerNavigationController *picker;

然后，

修改showPeoplePicker以设置该属性;和
修改addPerson以使用该属性：

因此：

- (void)addPerson
{
    ABNewPersonViewController *newPersonVC = [[ABNewPersonViewController alloc] init];
    newPersonVC.newPersonViewDelegate = self;
    UINavigationController *uiNav = [[UINavigationController alloc] initWithRootViewController:newPersonVC];

    [self.picker presentViewController:uiNav animated:YES completion:nil];
}

- (void)showPeoplePicker
{
    ABPeoplePickerNavigationController *picker = [[ABPeoplePickerNavigationController alloc] init];
    picker.peoplePickerDelegate = self;

    [self presentViewController:picker animated:YES completion:nil];
    [picker.topViewController setEditing:YES];
    picker.topViewController.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd    target:self action:@selector(addPerson)];
    picker.topViewController.navigationItem.leftBarButtonItem  = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(peoplePickerCancel)];

    self.picker = picker;
}

- (void)newPersonViewController:(ABNewPersonViewController *)newPersonView didCompleteWithNewPerson:(ABRecordRef)person
{
    [newPersonView dismissViewControllerAnimated:YES completion:nil];
}

iOS如何在已经堆叠的ViewController上调用presentViewController

1 个答案: