Camera and photo library in iOS Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of UIImagePickerController in iOS development?

UIImagePickerController is a built-in class that lets users pick images or videos from their photo library or take new photos or videos using the camera.

beginner

Which privacy key must be added to Info.plist to access the camera?

You must add the key NSCameraUsageDescription with a message explaining why your app needs camera access.

beginner

How do you check if the camera is available on an iOS device?

Use UIImagePickerController.isSourceTypeAvailable(.camera) to check if the device has a camera before trying to use it.

intermediate

What delegate protocol must your class conform to when using UIImagePickerController?

Your class must conform to <strong>UIImagePickerControllerDelegate</strong> and <strong>UINavigationControllerDelegate</strong> to handle image picking results and navigation events.

beginner

Why is it important to dismiss UIImagePickerController after picking an image?

Dismissing UIImagePickerController returns control to your app's interface and prevents the picker from blocking user interaction.

Which source type allows users to select photos from their library?

A .camera

B .photoLibrary

C .savedPhotosAlbum

D .video

The .photoLibrary source type lets users pick images or videos from their photo library.

What must you do before accessing the camera in your app?

A Enable background modes

B Request microphone permission

C Add NSCameraUsageDescription in Info.plist

D Nothing special is needed

You must add NSCameraUsageDescription in Info.plist to explain why your app needs camera access.

Which delegate method handles the event when a user finishes picking an image?

A imagePickerController(_:didFinishPickingMediaWithInfo:)

B imagePickerControllerDidCancel(_:)

C viewDidLoad()

D applicationDidBecomeActive()

imagePickerController(_:didFinishPickingMediaWithInfo:) is called when the user picks an image or video.

How do you check if the device supports taking photos?

A UIImagePickerController.isSourceTypeAvailable(.camera)

B UIDevice.current.hasCamera

C AVCaptureDevice.isAvailable()

D No check is needed

UIImagePickerController.isSourceTypeAvailable(.camera) returns true if the device has a camera.

What happens if you don't dismiss UIImagePickerController after use?

A The app automatically dismisses it

B The app crashes

C Nothing happens

D The picker stays on screen and blocks interaction

If you don't dismiss the picker, it remains visible and blocks user interaction with your app.

Explain the steps to let a user take a photo and use it in your app.

Think about permissions, presenting the camera, and handling the result.

Describe how to allow users to pick an existing photo from their library.

Focus on the photo library source and delegate handling.