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我正在尝试编写代码以从 iPad 上的照片库中选择图像。我正在使用的代码如下（取自 Apple 的网站），但它一直给我一个错误，说On iPad, UIImagePickerController must be presented via UIPopoverController. 我试过改变这一行：UIImagePickerController *mediaUI = [[UIImagePickerController alloc] init];使用 UIPopoverController，但显然我做错了什么，因为它不起作用。 

- (BOOL) selectImage: (UIViewController*) controller
       usingDelegate: (id <UIImagePickerControllerDelegate,
                       UINavigationControllerDelegate>) delegate {

    if (([UIImagePickerController isSourceTypeAvailable:
          UIImagePickerControllerSourceTypeSavedPhotosAlbum] == NO)
        || (delegate == nil)
        || (controller == nil))
        return NO;

    UIImagePickerController *mediaUI = [[UIImagePickerController alloc] init];
    mediaUI.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;

    // Displays saved pictures and movies, if both are available, from the
    // Camera Roll album.
    mediaUI.mediaTypes =
    [UIImagePickerController availableMediaTypesForSourceType:
     UIImagePickerControllerSourceTypeSavedPhotosAlbum];

    // Hides the controls for moving & scaling pictures, or for
    // trimming movies. To instead show the controls, use YES.
    mediaUI.allowsEditing = NO;

    mediaUI.delegate = delegate;

    [controller presentModalViewController: mediaUI animated: YES];
    return YES; }

Apple 开发人员页面还说：“在 iPad 上，您可以选择使用弹出框呈现浏览器界面，如 initWithContentViewController: 和 UIPopoverController 类参考中的“呈现和关闭弹出框”中所述。” 我读过它，但我仍然无法让它工作。任何帮助，将不胜感激。

4

4 回答 4

3

像这样的东西应该工作：

// create an image picker controller 
UIImagePickerController *imagePickerController = [[[UIImagePickerController alloc] init] autorelease];
imagePickerController.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
imagePickerController.delegate = self;

// present it in a popover
self.popoverController = [[[UIPopoverController alloc] initWithContentViewController:imagePickerController] autorelease];
self.popoverController.delegate = self;
// I was presenting the popover from a button, but you would set the rect to whatever is appropriate for your app
[self.popoverController presentPopoverFromRect:((UIButton *)sender).bounds inView:sender permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
于 2012-05-16T21:45:52.967 回答
1

声明一个 ivar，例如：

UIPopoverController *imagePopover;

然后：

imagePopover = [[UIPopoverController alloc] initWithContentViewController:mediaUI];
[imagePopover setDelegate:self];

[imagePopover presentPopoverFromRect:someRect
                              inView:someView
            permittedArrowDirections:UIPopoverArrowDirectionAny
                           animated:YES];

代替

[controller presentModal...];
于 2012-05-16T21:52:52.220 回答
1 
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];

imagePicker.delegate = self;

imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

popover = [[UIPopoverController alloc] initWithContentViewController:imagePicker];

[popover presentPopoverFromRect:CGRectMake(0.0, 0.0, 400.0, 400.0) 
                         inView:self.view
       permittedArrowDirections:UIPopoverArrowDirectionAny 
                       animated:YES];

参考下面的链接

http://www.techotopia.com/index.php/An_Example_iOS_4_iPad_Camera_and_UIImagePickerController_Application_%28Xcode_4%29

于 2012-05-17T05:58:49.793 回答
1

我经历了很多痛苦，想出了一个适用于 iPad 和 iPhone 的解决方案，这是最终代码，其中一些来自其他人的评论：代码有一些错误，但它是一个很好的起点： ) 它涵盖了所需的权限以及如何管理 ipad 上弹出的视图控制器。

需要以下进口：

#import <AVFoundation/AVFoundation.h>
#import <AssetsLibrary/AssetsLibrary.h>

并添加这个代表：

UIActionSheetDelegate, UIImagePickerControllerDelegate

定义：

__weak IBOutlet UIButton *attachButton;
UIImage *image;

按钮的作用：

    - (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;

}
于 2016-04-09T21:09:18.667 回答