Question

在我的UINavigationController个观看次数中，用户可以按“添加”按钮，使用UIImagePickerController从相册中选择照片。当用户选择所需照片时，我想将他移至AddPhotoViewController视图，在那里他可以添加标题和说明，而不是按“保存”按钮保存数据，取消AddPhotoViewController视图并返回上一个{{ 1}}查看。到目前为止，我只能推动UINavigationController视图，我不能将其作为模态视图。这就是我这样做的方式：

AddPhotoViewController

上面的代码工作正常，但我想添加AddPhotoViewController作为模态视图。我想使用-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info { AddPhotoViewController *apvc = [self.storyboard instantiateViewControllerWithIdentifier:@"addPhoto"]; apvc.info = info; [self.navigationController pushViewController:apvc animated:YES]; [self dismissViewControllerAnimated:YES completion:nil]; }，但在iOS 6.0中已经过折旧。比我尝试过：

presentModalViewController:animated:

而不是：

   [self presentViewController:apvc animated:YES completion:nil];

但是我收到了这个错误：

   [self.navigationController pushViewController:apvc animated:YES];

在我解除Warning: Attempt to present <AddPhotoViewController: 0x1e183fc0> on <UINavigationController: 0x1d594a70> whose view is not in the window hierarchy!视图后，是否可以在UINavigationController视图的顶部添加模态视图？

Answer 1

首先关闭当前模态控制器，然后再显示另一个控制器。即

    -(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
          AddPhotoViewController *apvc = [self.storyboard instantiateViewControllerWithIdentifier:@"addPhoto"];
          apvc.info = info;
          [self dismissViewControllerAnimated:YES completion:nil];

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

Answer 2

你为什么不使用segue？在故事板中设置你的segue，当从imagepickercontroller返回时，只需从代码中触发seque。

您可以参考seque的http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/CreatingCustomSegues/CreatingCustomSegues.html

Answer 3

与@ nkongara的答案类似，但通过使用完成块来避免任何奇怪的竞争条件更加强大。此外，通过在dismissViewControllerAnimated:completion上调用[picker presentingViewController]而不是假设self始终是呈现视图控制器，代码更具有前瞻性/防弹性。

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    AddPhotoViewController *apvc = [self.storyboard instantiateViewControllerWithIdentifier:@"addPhoto"];
    apvc.info = info;
    [[picker presentingViewController] dismissViewControllerAnimated:YES completion:^{
        [self presentViewController:apvc animated:YES completion:nil];
    }];
}

Answer 4

由于放松赛道的魔力，你可以获得你想要的导航......

在第一个viewController中，实现一个展开segue

- (IBAction)unwindSegue:(UIStoryboardSegue*)segue
{
    NSLog (@"unwound");
       //you can extract data from your "addPhoto" viewController here
       //via segue.sourceViewController
}

请务必在头文件中声明它。

在“addPhoto”viewController中，添加某种类型的消除按钮，然后按住CTRL键拖动到控制器底部的“退出”符号。展开segue应该是可选择的。

要访问addPhoto，您可以以模态方式呈现它 - 但请imagePickerController进行演示：

- (void) imagePickerController:(UIImagePickerController *)picker
 didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIViewController* addPhotoController = 
                [self.storyboard instantiateViewControllerWithIdentifier:@"addPhoto"];

    addPhotoController.infoDict = info; //passing the image data to addPhoto

    [picker presentViewController:addPhotoController 
                         animated:YES 
                       completion:nil];
}

所以你确实得到了两层呈现，但在每种情况下都是前一个控制器来进行呈现。 DON“T关闭imagePickerController。当执行unwind segue时，它将为你解雇。

Answer 5

正如其他人在此提到的那样，无法在当前模态视图和父视图之间添加第二个模态视图。我解决了我的问题但它更像是一个黑客而不是真正的解决方案。如果有人想要做类似的事情，这是解释的链接：http://xissburg.com/presenting-multiple-modal-view-controllers-at-once/

如何以编程方式在UINavigationController中显示第二个模态ViewController

5 个答案: