Programming iOS 6, 3rd Edition

UIImagePickerController

UIImagePickerController is a view controller (UINavigationController) whose view provides a navigation interface, similar to the Photos app, in which the user can choose an item from the photo library. Alternatively, it can provide an interface, similar to the Camera app, for taking a video or still photo if the necessary hardware is present.

How you display the UIImagePickerController depends on what kind of device this is:

On the iPhone

You will typically display the view controller’s view as a presented view controller. This presented view controller will appear in portrait orientation, regardless of your app’s rotation settings.

On the iPad

If you’re letting the user choose an item from the photo library, you’ll show it in a popover; attempting to display it as a presented view controller causes a runtime exception. (To see how to structure your universal app code, look at Example 29-1). But if you’re letting the user take a video or still photo, you’ll probably treat UIImagePickerController as a presented view controller on the iPad, just as on the iPhone.

Choosing from the Photo Library

To let the user choose an item from the photo library, instantiate UIImagePickerController and assign its sourceType one of these values:

UIImagePickerControllerSourceTypeSavedPhotosAlbum

The user is confined to the contents of the Camera Roll / Saved Photos album.

UIImagePickerControllerSourceTypePhotoLibrary

The user is shown a table of all albums, and can navigate ...