Question

我有适用于iPhone和iPad的通用应用程序。使用下面的代码我试图从照片库或相机中获取图片。对于iphone它的工作正常，但对于iPad，当我点击警报视图中的任何按钮时，它不会显示任何内容。可能是什么问题？

-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex {

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {

    if (buttonIndex == 0) {
        UIImagePickerController* picker = [[UIImagePickerController alloc] init];
        picker.allowsEditing = YES;
        picker.delegate   = self;
        camera = NO;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

        [self presentModalViewController:picker animated:YES];


    } else if (buttonIndex == 1) {

        BOOL hasCamera = [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera];
        camera = YES;
        UIImagePickerController* picker = [[UIImagePickerController alloc] init];
        picker.allowsEditing = YES;
        picker.delegate   = self;
        picker.sourceType = hasCamera ? UIImagePickerControllerSourceTypeCamera : UIImagePickerControllerSourceTypePhotoLibrary;

        [self presentModalViewController:picker animated:YES];

        }
    }else {
    // We are using an iPad
    UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
    imagePickerController.delegate = self;
    popoverController=[[UIPopoverController alloc] initWithContentViewController:imagePickerController];
    popoverController.delegate=self;
    [popoverController presentPopoverFromRect:[self.view bounds] inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    }

}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    if (clickedButton == YES) {

            UIImage *originalImage, *editedImage;

            editedImage = (UIImage *) [info objectForKey: UIImagePickerControllerEditedImage];

            originalImage = (UIImage *) [info objectForKey: UIImagePickerControllerOriginalImage];

            if (editedImage) {

                thisImage = editedImage;

            } else {

                thisImage = originalImage;

            }

            imageThis.image = thisImage;

        NSData *imageData = UIImageJPEGRepresentation(thisImage, 30);

        [defaults setObject:imageData forKey:@"thisImage"];

        [defaults synchronize];

     //   [[NSUserDefaults standardUserDefaults] setObject:UIImagePNGRepresentation(thisImage) forKey:@"thisImage"];

    }
    else {

        UIImage *originalImage, *editedImage;

        editedImage = (UIImage *) [info objectForKey: UIImagePickerControllerEditedImage];

        originalImage = (UIImage *) [info objectForKey: UIImagePickerControllerOriginalImage];

        if (editedImage) {

            thatImage = editedImage;

        } else {

            thatImage = originalImage;

        }

        imageThat.image = thatImage;

        NSData *imageData = UIImageJPEGRepresentation(thatImage, 30);

        [defaults setObject:imageData forKey:@"thatImage"];

        [defaults synchronize];

        //[[NSUserDefaults standardUserDefaults] setObject:UIImagePNGRepresentation(thatImage) forKey:@"thatImage"];

    }

    [picker dismissModalViewControllerAnimated:YES];
}

Answer 1

那是因为你在iPad上使用UIActionSheet。在iPad上，UIActionSheet使用UIPopoverController呈现工作表，而在UIActionSheetDelegate方法中，当UIActionsheet使用的第一个UIPopoverController未被隐藏时，您使用另一个UIPopoverController。您需要知道的是，任何时候屏幕上都只能显示一个UIPopoverController。

Answer 2

就是这一行：

[popoverController presentPopoverFromRect:[self.view bounds] inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

您需要从控制器视图中的矩形出现（我假设self是视图控制器），否则您会得到奇怪的结果。刚刚进行测试时，我有一个弹出窗口拒绝出现，其中一个弹出窗口以箭头为中心出现在屏幕上。例如：

[popoverController presentPopoverFromRect:[myButtonOutlet frame] inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

UIPopoverController不会出现在iPad上

2 个答案: