Question

其他人在iOS 8中遇到UIImagePickerController的问题吗？下面的方法在iPad上的iOS 7中运行得非常好，但是当我尝试呈现选择器（最后一行）时，我在XCode 6（Beta 3或4）中运行时会出现以下错误。如果重要，那么sourceType的选择来自于在同一个地方呈现的alertView。

Warning: Attempt to present <UIImagePickerController: 0x7c0ae400>  on <CAGUCreateContactViewController: 0x7bf61a00> which is already presenting (null)

打开imagePicker的方法。

- (void)openPhotoPicker:(UIImagePickerControllerSourceType)sourceType
{
    if ([UIImagePickerController isSourceTypeAvailable:sourceType]) {
        NSArray *availableMediaTypes = [UIImagePickerController availableMediaTypesForSourceType:sourceType];
        if ([availableMediaTypes containsObject:(NSString *)kUTTypeImage]) {
            UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
            imagePickerController.modalPresentationStyle = UIModalPresentationFullScreen;
            imagePickerController.sourceType = sourceType;
            imagePickerController.mediaTypes = @[(NSString *)kUTTypeImage];
            imagePickerController.delegate = self;

            self.imagePickerController = imagePickerController;

            if (sourceType == UIImagePickerControllerSourceTypeCamera) {
                [self presentViewController:self.imagePickerController animated:YES completion:nil];
            } else {                    
                if (self.popoverVC) {
                    [self.popoverVC dismissPopoverAnimated:YES];
                    self.popoverVC = nil;
                }

                self.popoverVC = [[UIPopoverController alloc] initWithContentViewController:imagePickerController];
                [self.popoverVC presentPopoverFromRect:self.nameAndPicCell.picture.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];
            }
        }
    }
}

Answer 1

我认为这是因为在iOS 8中，警报视图和操作表实际上是视图控制器（UIAlertController）。因此，如果您正在呈现新的视图控制器以响应UIAlertView中的操作，则会在UIAlertController被解雇时显示该视图。我通过将UIImagePickerController的表示延迟到runloop的下一次迭代来解决这个问题，通过这样做：

[[NSOperationQueue mainQueue] addOperationWithBlock:^{
    [self openPhotoPicker:sourceType];
}];

但是，解决此问题的正确方法是在iOS 8上使用新的UIAlertController API（即使用if ([UIAlertController class]) ...来测试它）。如果您尚未使用新API，这只是一种解决方法。

Answer 2

我同意Ben Lings的问题检测。在使用UIActionSheet时，我会建议一个更简单的解决方案。我只是简单地移动了我的代码，该代码对Action Sheet的选择做出了反应：

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex;
{
// my code
}

成：

- (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex;  // after animation
{
// my code
}

这样，应用程序可以保证在UIActionSheet动画完成后将执行代码。

由于UIAlertView具有类似的委托方法：

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex;  // after animation
{
// my code
}

我认为类似的解决方案可能适用。

Answer 3

这是一个适合我的解决方案

if([[[UIDevice currentDevice] systemVersion] floatValue]>=8.0)
{
    [[NSOperationQueue mainQueue] addOperationWithBlock:^{

        [self presentViewController:cameraUI animated:NO completion:nil];
    }];

}
else{

    [controller presentViewController:cameraUI animated:NO completion:nil];
}

请记得分配cameraUI

UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;

Build and Go！

Answer 4

我在iOS 8中遇到了同样的问题。然后我看到了iOS上最新更新的更改日志，即设备上的8.0.2。

本次更新中提到_

＆＃34;修复了导致某些应用无法访问照片库中的照片的问题＆＃34;

因此，在iOS 8.0.2版本的设备上使用XCode 6测试您的应用程序，它可以正常工作不要在iOS 8.0模拟器上测试它。

这对我有所帮助，希望对你有同感。

Screen-shot of iOS 8.0.2 Update change log

Answer 5

UIImagePickerController *imagePickerController= [[UIImagePickerController alloc] init];
[imagePickerController setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];

// image picker needs a delegate so we can respond to its messages
[imagePickerController setDelegate:self];
self.shouldCallViewWillAppear = NO;

if(IS_IOS8)
{
    [[NSOperationQueue mainQueue] addOperationWithBlock:^{
        // Place image picker on the screen
        [self presentViewController:imagePickerController animated:YES completion:nil];
    }];
}
else
{
    [self presentViewController:imagePickerController animated:YES completion:nil];
}

Answer 6

您可以使用

关闭呈现的视图控制器（如果有）

[self.presentedViewController dismissViewControllerAnimated:YES completion:nil];

这对我有用。

Answer 7

您需要做的就是解雇已经呈现的ViewController：

if (self.presentedViewController) {
    [self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
}

[self openPhotoPicker:sourceType];

如果仍然产生错误，请将openPhotoPicker：放入完成处理程序

Answer 8

在iOS 8上，您应该使用新的API：

if (SYSTEM_VERSION_IOS_8) {
    self.imagePickerController.modalPresentationStyle = UIModalPresentationPopover;
    UIPopoverPresentationController *popPC = self.imagePickerController.popoverPresentationController;
    popPC.barButtonItem = self.popoverItem;
    popPC.permittedArrowDirections = UIPopoverArrowDirectionAny;
    [self presentViewController:self.imagePickerController animated:YES completion:nil]
}

我建议您观看2014 WWDC session 228 a look in side presentation controllers

Answer 9

我只是这样做了：

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND,
                                         (unsigned long)NULL), ^(void) {

    [self retractActivePopover];

    dispatch_async(dispatch_get_main_queue(), ^ {

        _activePopover=imagePickerPopover;

        UIBarButtonItem *callingButton = (UIBarButtonItem*) sender;

        [imagePickerPopover presentPopoverFromBarButtonItem:callingButton permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];

    });

});

Answer 10

我经历了很多痛苦，提出了一个适用于iPad和iPhone的解决方案，这是最终的代码，其中一些来自其他人的评论：代码有一些错误，但它是一个非常好的起点:)

定义：

__weak IBOutlet UIButton *attachButton;
UIImage *image;

按钮的操作：

    - (IBAction)doAttach:(id)sender {
    UIActionSheet *action = [[UIActionSheet alloc] initWithTitle:@"Select image from" delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:@"From library",@"From camera", nil] ;
    [action showInView:self.view];
  }



#pragma mark - ActionSheet delegates

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
    if( buttonIndex == 1 ) {
        AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
        if(authStatus == AVAuthorizationStatusAuthorized)
        {
            NSLog(@"%@", @"You have camera access");
        }
        else if(authStatus == AVAuthorizationStatusDenied)
        {
            NSLog(@"%@", @"Denied camera access");

            [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
                if(granted){
                    NSLog(@"Granted access to %@", AVMediaTypeVideo);
                } else {
                    [self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
                    UIAlertController* alert = [UIAlertController alertControllerWithTitle:@“no camera access“
                                                                                   message: @“if you need to use camera in this application go to settings -> appName -> and turn on camera.”
                                                                            preferredStyle:UIAlertControllerStyleAlert];

                    UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@“ok” style:UIAlertActionStyleDefault
                                                                          handler:^(UIAlertAction * action) {
                                                                          }];
                    [alert addAction:defaultAction];

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


                    NSLog(@"Not granted access to %@", AVMediaTypeVideo);
                    return ;
                }
            }];
        }
        else if(authStatus == AVAuthorizationStatusRestricted)
        {
            [self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
            UIAlertController* alert = [UIAlertController alertControllerWithTitle:@“no camera access“
                                                                                   message: @“if you need to use camera in this application go to settings -> appName -> and turn on camera.”
                                                                            preferredStyle:UIAlertControllerStyleAlert];

            UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@“ok” style:UIAlertActionStyleDefault
                                                                  handler:^(UIAlertAction * action) {
                                                                  }];
            [alert addAction:defaultAction];

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


            NSLog(@"%@", @"Restricted, normally won't happen");
        }
        else if(authStatus == AVAuthorizationStatusNotDetermined)
        {
            NSLog(@"%@", @"Camera access not determined. Ask for permission.");

            [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
                if(granted){
                    NSLog(@"Granted access to %@", AVMediaTypeVideo);
                } else {
                    NSLog(@"Not granted access to %@", AVMediaTypeVideo);
                    return ;
                }
            }];
        }
        else
        {
            [self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
            UIAlertController* alert = [UIAlertController alertControllerWithTitle:@“No camera access“
                                                                           message: @“error accusing camera”
                                                                    preferredStyle:UIAlertControllerStyleAlert];

            UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@“ok” style:UIAlertActionStyleDefault
                                                                  handler:^(UIAlertAction * action) {
                                                                  }];
            [alert addAction:defaultAction];

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


            return;
            //NSLog(@"%@", @"Camera access unknown error.");
        }

        if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {


            UIImagePickerController *pickerView =[[UIImagePickerController alloc]init];
            pickerView.allowsEditing = YES;
            pickerView.delegate = self;
            pickerView.sourceType = UIImagePickerControllerSourceTypeCamera;


            if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {

                [ self.presentedViewController dismissViewControllerAnimated:YES completion:nil ];

                pickerView.modalPresentationStyle = UIModalPresentationPopover;
                UIPopoverPresentationController *popPC = pickerView.popoverPresentationController;
                popPC.sourceView = attachButton;
                popPC.permittedArrowDirections = UIPopoverArrowDirectionAny;
                [self presentViewController:pickerView animated:YES completion:nil];
            } else {
                [self presentModalViewController:pickerView animated:YES ];
            }
        }

    }else if( buttonIndex == 0 ) {

        ALAuthorizationStatus status = [ALAssetsLibrary authorizationStatus];
        switch (status) {
            case ALAuthorizationStatusRestricted:
            case ALAuthorizationStatusDenied:
            {
                [self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
                UIAlertController* alert = [UIAlertController alertControllerWithTitle:@“no access to library”
                                                                               message: @“if you wish to access photos in this app go to settings -> appName-> and turn on photos .”
                                                                        preferredStyle:UIAlertControllerStyleAlert];

                UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@“ok” style:UIAlertActionStyleDefault
                                                                      handler:^(UIAlertAction * action) {
                                                                      }];
                [alert addAction:defaultAction];

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

            }
                break;

            default:
            {
                UIImagePickerController *pickerView = [[UIImagePickerController alloc] init];
                pickerView.allowsEditing = YES;
                pickerView.delegate = self;

                [pickerView setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];


                if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {

                    [ self.presentedViewController dismissViewControllerAnimated:YES completion:nil ];

                    pickerView.modalPresentationStyle = UIModalPresentationPopover;
                    UIPopoverPresentationController *popup = pickerView.popoverPresentationController;
                    popup.sourceView = attachButton;
                    popup.permittedArrowDirections = UIPopoverArrowDirectionAny;
                    [self presentViewController:pickerView animated:YES completion:nil];
                } else {
                    [self presentModalViewController:pickerView animated:YES ];
                }
            }
                break;
        }



    }
}

#pragma mark - PickerDelegates

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{

    [self dismissModalViewControllerAnimated:true];

    UIImage * img = [info valueForKey:UIImagePickerControllerEditedImage];
    image = img;

}

Answer 11

performSelector：withObject：afterDelay解决了我的问题。

还有didDismissWithButtonIndex可以做到这一点。

最高

Answer 12

这是一个Xamarin解决方案。对我有用的是将我的动作添加到Dismissed事件处理程序。

this.btnPhoto.TouchUpInside += (sender, e) =>
{
    actionSheet = new UIActionSheet ("Add Photo");
    actionSheet.AddButton ("Take Photo");
    actionSheet.AddButton ("Select from Library");
    actionSheet.AddButton ("Cancel");
    actionSheet.DestructiveButtonIndex = -1; // red
    actionSheet.CancelButtonIndex = 3;  // black
    actionSheet.Clicked += delegate(object a, UIButtonEventArgs b)
    {
        actionSheet.Dismissed += (object aSender, UIButtonEventArgs dismissArgs) => 
        {
            switch (dismissArgs.ButtonIndex)
            {
                case 0:
                    showCamera ();
                    break;
                case 1:
                    showPhotoLibrary ();
                    break;
            }
        };
    };
    actionSheet.ShowInView (view);
};

UIImagePickerController没有在iOS 8中呈现

12 个答案: