📸 Working with Camera and Photo Library (iOS – Xcode)

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✅ 1. Definition

🔹 Camera Access

Camera access allows an iOS app to capture photos or videos using the device camera.

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🔹 Photo Library Access

Photo Library access allows an app to select and use existing images/videos stored on the device.

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👉 In simple words:

• 📷 Camera = take new photos/videos
• 🖼️ Photo Library = choose existing media

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🧠 2. Key Concepts

🔹 UIImagePickerController

A built-in iOS class used to:

• Open camera
• Open photo library
• Select media

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🔹 Delegates Used

To handle results:

• UIImagePickerControllerDelegate
• UINavigationControllerDelegate

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🔹 Privacy Permissions (Important)

iOS requires user permission:

• Camera usage
• Photo library access

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⚙️ 3. Import Required Frameworks

import UIKit

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📷 4. Using the Camera

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🔹 Step 1: Check Camera Availability

if UIImagePickerController.isSourceTypeAvailable(.camera) {
    print("Camera available")
}

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🔹 Step 2: Open Camera

let picker = UIImagePickerController()
picker.sourceType = .camera
picker.delegate = self
present(picker, animated: true)

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🖼️ 5. Using Photo Library

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🔹 Step 1: Open Gallery

let picker = UIImagePickerController()
picker.sourceType = .photoLibrary
picker.delegate = self
present(picker, animated: true)

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📥 6. Handling Selected Image

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🔹 Delegate Method

func imagePickerController(_ picker: UIImagePickerController,
                           didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

    if let image = info[.originalImage] as? UIImage {
        imageView.image = image
    }

    picker.dismiss(animated: true)
}

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🔹 Cancel Action

func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
    picker.dismiss(animated: true)
}

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📊 7. Full Flow Diagram

User taps button
      ↓
UIImagePickerController opens
      ↓
Camera / Photo Library
      ↓
User selects or captures image
      ↓
Delegate returns image
      ↓
Image displayed in app

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🔐 8. Required Permissions (VERY IMPORTANT)

Add in Info.plist:

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🔹 Camera Permission

Privacy - Camera Usage Description
We need camera access to take photos.

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🔹 Photo Library Permission

Privacy - Photo Library Usage Description
We need access to your photos.

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💡 9. Example App

🎯 Profile App

• User taps “Change Profile Picture”
• Opens camera or gallery
• Selects image
• Image updates profile picture

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📌 10. Important Rules / Tips

• Always set delegate
• Always add permissions in Info.plist
• Test camera on real device (not simulator)
• Check camera availability before using
• Dismiss picker after selection

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⚠️ 11. Common Mistakes

• ❌ Missing privacy permissions → app crash
• ❌ Testing camera on simulator
• ❌ Not setting delegate
• ❌ Forgetting to dismiss image picker
• ❌ Force unwrapping image data

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🧠 12. Best Practices

• Always check source availability
• Use proper permission messages
• Handle cancel action properly
• Use image compression if needed
• Keep UI simple for media selection

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📝 13. Likely Exam Questions

1. What is UIImagePickerController?
2. How do you access the camera in iOS?
3. What is the difference between camera and photo library?
4. Why are permissions required in iOS apps?
5. Write code to select image from gallery.
6. What delegate methods are used for image picker?
7. Why can camera not work in simulator?
8. What must be added in Info.plist for camera access?

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📚 14. Quick Revision Summary

• Camera → capture new images

• Photo Library → select existing images

• Uses UIImagePickerController

• Requires permissions in Info.plist

• Delegate methods handle results

• Must test camera on real device

• Common in:

  • Social apps
  • Profile apps
  • Editing apps

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