Using presentModalViewController with UIImagePicke

问题:

Using presentModalViewController with UIImagePickerController causing Crash on iOS 5 (its running fine on version<5), i am trying to get all the albums on the device, using 'UIImagePickerControllerSourceTypeSavedPhotosAlbum' is only getting the Camera images, so when i change the sourceType to 'UIImagePickerControllerSourceTypePhotoLibrary' it crashes, i appreciate any help, here is my code:

float version = [[[UIDevice currentDevice] systemVersion] floatValue];
    if(version < 5) 
        imgPicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    else                        
        imgPicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        //imgPicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;

    [self presentModalViewController:imgPicker animated:YES];

回答1:

From the official doc:

To use an image picker controller containing its default controls, perform these steps:

1. Verify that the device is capable of picking content from the desired source. Do this calling the isSourceTypeAvailable: class method, providing a constant from the “UIImagePickerControllerSourceType” enum.

2. Check which media types are available, for the source type you’re using, by calling the availableMediaTypesForSourceType: class method. This lets you distinguish between a camera that can be used for video recording and one that can be used only for still images.

3. Tell the image picker controller to adjust the UI according to the media types you want to make available—still images, movies, or both—by setting the mediaTypes property.

4. Present the user interface by calling the presentViewController:animated:completion: method of the currently active view controller, passing your configured image picker controller as the new view controller.

   On iPad, present the user interface using a popover. Doing so is valid only if the sourceType property of the image picker controller is set to UIImagePickerControllerSourceTypeCamera. To use a popover controller, use the methods described in “Presenting and Dismissing the Popover” in UIPopoverController Class Reference.

5. When the user taps a button to pick a newly-captured or saved image or movie, or cancels the operation, dismiss the image picker using your delegate object. For newly-captured media, your delegate can then save it to the Camera Roll on the device. For previously-saved media, your delegate can then use the image data according to the purpose of your app

Maybe point 4 is causing troubles.