This document provides code samples for working with photos and the camera in iOS. It includes code to: 1. Request camera and photo library permissions. 2. Open the camera or photo library using UIImagePickerController. 3. Display selected photos and handle the delegate callbacks. 4. Save photos to the camera roll or a custom album using Photos framework APIs. 5. Retrieve metadata from photos using Photos framework objects like PHAsset. It also discusses using CoreImage for features like adding stickers to photos and face detection.

1. Camera·Photo
卡麥拉·佛托的廣角鏡頭
Swift Girls Part 7
20170807
張筱姍

2. 張筱姍
HsiaoShan Chang
目前最愛寫程式跟織毛線。
目標是開發出手作相關工具或平台讓大家可以快樂
的做手作！
KCCounter-棒針鉤針必備編織計數器
創業歐北共 紛絲專頁

3. Instagram

4. Line

5. 影像編輯

6. 最基本3件事情
拍照
從手機取出照片
儲存照片至手機

7. info.plist
設定Usage Description
取用相機說明:
Privacy - Camera Usage Description
取用照片說明:
Privacy - Photo Usage Description
ata without a usage description. The app's Info.plist must contain an NSCameraUsageDescription
Error

8. UIImagePickerController
sourceType:
UIImagePickerControllerSourceType camera -
相機
photoLibrary - 所有相簿 (預設值)
savedPhotoAlbum - 所有照片
delegate: UIImagePickerControllerDelegate &
UINavigationControllerDelegate

9. UIImagePickerControllerDelega
te
func imagePickerController(_ picker:
UIImagePickerController,
didFinishPickingMediaWithInfo info: [String :
Any])
func imagePickerControllerDidCancel(_ picker:
UIImagePickerController)

10. Important
The Assets Library framework is deprecated as of iOS
9.0. Instead, use the Photos framework instead, which in
iOS 8.0 and later provides more features and better
performance for working with a user’s photo library.
PhotosAssetsLibrary
iOS 8.0+

11. Photos Framework iOS 8.0+

12. Photos Framework
Model Object
PHAssetCollection
PHAsset
PHCollectionList

13. Photos Framework iOS 8.0+

14. 實作
1. 打開相機拍照
2. 打開相簿
3. 將照片顯示在畫面上
4. 儲存至相機膠卷
5. 取得照片內容metadata
6. 將照片儲存至自訂相簿

15. 實作 - 1.打開相機拍照-1
override func viewDidLoad() {
super.viewDidLoad()
//請求相機權限
AVCaptureDevice.requestAccess(forMediaType: AVMediaTypeVideo)
{ granted in
print("camera access:(granted)")
}
}

16. 實作 - 1.打開相機拍照-2
@IBAction func goCamera(_ sender: Any) {
guard AVCaptureDevice.authorizationStatus(forMediaType: AVMediaTypeVideo) ==
.authorized else {
print("not authorized....")
return
}
guard UIImagePickerController.isSourceTypeAvailable(.camera) else {
print("Camera not available.”)
return
}
let controller = UIImagePickerController()
controller.sourceType = .camera
controller.delegate = self
self.present(controller, animated: true, completion: nil)
}

17. 實作 - 2.打開相簿-1
override func viewDidLoad() {
super.viewDidLoad()
//請求照片權限
PHPhotoLibrary.requestAuthorization { (status) in
switch status {
case .authorized:
print("authorized..")
case .denied:
print("denied..")
case .notDetermined:
print("notDetermined..")
case .restricted:
print("restricted..")
}
}
}

18. 實作 - 2.打開相簿-2
@IBAction func goPhoto(_ sender: Any) {
guard PHPhotoLibrary.authorizationStatus() == .authorized else {
print("PHPhotoLibrary not available.")
return
}
guard UIImagePickerController.isSourceTypeAvailable(.camera) else {
print("Camera not available.")
return
}
let controller = UIImagePickerController()
controller.sourceType = .photoLibrary
controller.delegate = self
self.present(controller, animated: true, completion: nil)
}

19. 實作 - 3.將照片顯示在畫面
func imagePickerController(_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [String : Any]) {
print(".....info.....n(info)")
//從info取出拍好的照片
if let pickedPhoto =
info[UIImagePickerControllerOriginalImage] as? UIImage
{
img.image = pickedPhoto
}
//把相機畫面關掉
picker.dismiss(animated: true, completion: nil)
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
print("Cancel imagePickerController.”)
picker.dismiss(animated: true, completion: nil)
}

20. 實作 - 4.儲存至相機膠卷
//1. UIKit method, iOS 2.0+
UIImageWriteToSavedPhotosAlbum(pickedPhoto, nil, nil, nil)
//2. Use Photos Library ,iOS 8.0+
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAsset(from: pickedPhoto)
}, completionHandler: {success, error in
if success {
print("save success.")
} else {
print("error creating asset: (String(describing: error))")
}
})

21. 實作 - 5.取得照片內容metadata
//取得PHAsset, iOS 4.1-11.0, Deprecated
if let assetURL = info[UIImagePickerControllerReferenceURL] as? NSURL {
let asset = PHAsset.fetchAssets(withALAssetURLs: [assetURL as URL], options: nil)
guard let result = asset.firstObject else {
return
}
//取得ImageData
PHImageManager.default().requestImageData(for: result , options: nil, resultHandler:{
(data, responseString, imageOriet, info) -> Void in
let imageData: NSData = data! as NSData
if let imageSource = CGImageSourceCreateWithData(imageData, nil) {
let imgprop = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil)! as NSDictionary
print(“....metadata....(imgprop)")
let pixelHeight = imgprop["PixelHeight"] as? Int
let pixelWidth = imgprop["PixelWidth"] as? Int
print("Height:(pixelHeight ?? 0)")
print("Width:(pixelWidth ?? 0)")
}
})
}
//取得PHAsset, iOS 11.0+
if let result = info[UIImagePickerControllerPHAsset] as? PHAsset {

22. 實作 - 6.將照片儲存至
自訂相簿-1
var myAlbum: PHAssetCollection?
override func viewDidLoad() {
super.viewDidLoad()
//取得自訂相簿,不存在則建立自定相簿
if let collection = fetchAssetCollection(with: "SwiftGirls") {
myAlbum = collection
} else {
PHPhotoLibrary.shared().performChanges({
PHAssetCollectionChangeRequest
.creationRequestForAssetCollection(withTitle: "SwiftGirls")
}) { success, error in
if success {
print("Custom album create success.")
if let album = self
.fetchAssetCollection(with: "SwiftGirls") {
self.myAlbum = album
}
} else {
print("error creating album: (String(describing: error))")
}
}
}
}

23. 實作 - 6.將照片儲存至
自訂相簿-2
//依照相簿名稱取得相簿,不存在則回nil
func fetchAssetCollection(with name: String) -> PHAssetCollection? {
let fetchOptions = PHFetchOptions()
fetchOptions.predicate =
NSPredicate(format: "title = %@", name)
let collections = PHAssetCollection
.fetchAssetCollections(with: .album, subtype: .any, options: fetchOptions)
if let collection = collections.firstObject {
return collection
}
return nil
}

24. 實作 - 6.將照片儲存至
自訂相簿-3
//儲存照片至自訂相簿
@IBAction func saveToCustomAlbum(_ sender: Any) {
if self.img.image == nil {
return
}
guard myAlbum != nil else {
print("Custom album not found.")
return
}
//儲存照片至指定相簿
PHPhotoLibrary.shared().performChanges({
let assetChangeRequest = PHAssetChangeRequest
.creationRequestForAsset(from: self.img.image!)
let assetPlaceHolder = assetChangeRequest.placeholderForCreatedAsset
let albumChangeRequest = PHAssetCollectionChangeRequest(for: self.myAlbum!)
let enumeration: NSArray = [assetPlaceHolder!]
albumChangeRequest!.addAssets(enumeration)
}, completionHandler: {success, error in
if success {
print("save success.")
} else {
print("error creating asset: (String(describing: error))")
}
})
}

25. 進階實作
加貼圖

26. myImageView
放原來照片
(UIImageView)
myImageView.subviews

27. 進階實作
CoreImage
臉部辨識
Content Mode:
Aspect Fit

29. Homework
完成
6個實作＋2個進階實作