Questions about removing ios photo asset in Swift - ios

Question

This source code is a photo app like the iPhone's photo app.
When you launch the app, each Asset that is a CollectionViewCell is shown.
What I would like to ask is the ability to select and delete an image asset. If you look at the iPhone photo app, you can press the select button to select photos and delete and share selected photos. You can choose as many photos as you want rather than just one. I have implemented #IBAction selectButtonPressed.
class PhotoCollectionViewController: UICollectionViewController {
#IBOutlet weak var sortButton: UIBarButtonItem!
#IBOutlet weak var selectButton: UIBarButtonItem!
#IBOutlet weak var actionButton: UIBarButtonItem!
#IBOutlet weak var trashButton: UIBarButtonItem!
// MARK:- Properties
var fetchResult: PHFetchResult<PHAsset>? {
didSet {
OperationQueue.main.addOperation {
self.collectionView?.reloadSections(IndexSet(0...0))
}
}
}
var assetCollection: PHAssetCollection?
// MARK:- Privates
private let cellReuseIdentifier: String = "photoCell"
private lazy var cachingImageManager: PHCachingImageManager = {
return PHCachingImageManager()
}()
// MARK:- Life Cycle
deinit {
PHPhotoLibrary.shared().unregisterChangeObserver(self)
}
#IBAction func sortButtonPressed(_ sender: UIBarButtonItem) {
let fetchOptions: PHFetchOptions = PHFetchOptions()
if (self.sortButton.title == "In the past") {
fetchOptions.sortDescriptors = [NSSortDescriptor(key: "modificationDate",
ascending: false)]
self.fetchResult = PHAsset.fetchAssets(in: assetCollection!, options: fetchOptions )
self.sortButton.title = "The latest"
} else if (self.sortButton.title == "The latest") {
fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate",
ascending: true)]
self.fetchResult = PHAsset.fetchAssets(in: assetCollection!, options: fetchOptions )
self.sortButton.title = "In the past"
}
}
#IBAction func seletButtonPressed(_ sender: Any) {
if (self.sortButton.isEnabled == true) {
self.sortButton.isEnabled = false
self.actionButton.isEnabled = true
self.trashButton.isEnabled = true
} else if (self.sortButton.isEnabled == false) {
self.sortButton.isEnabled = true
self.actionButton.isEnabled = false
self.trashButton.isEnabled = false
}
PHPhotoLibrary.shared().performChanges({
//Delete Photo
PHAssetChangeRequest.deleteAssets(self.fetchResult!)
},
completionHandler: {(success, error)in
NSLog("\nDeleted Image -> %#", (success ? "Success":"Error!"))
if(success){
}else{
print("Error: \(error)")
}
})
}
}
extension PhotoCollectionViewController {
private func configureCell(_ cell: PhotoCollectionViewCell,
collectionView: UICollectionView,
indexPath: IndexPath) {
guard let asset: PHAsset = self.fetchResult?.object(at: indexPath.item) else { return }
let manager: PHCachingImageManager = self.cachingImageManager
let handler: (UIImage?, [AnyHashable:Any]?) -> Void = { image, _ in
let cellAtIndex: UICollectionViewCell? = collectionView.cellForItem(at: indexPath)
guard let cell: PhotoCollectionViewCell = cellAtIndex as? PhotoCollectionViewCell
else { return }
cell.imageView.image = image
}
manager.requestImage(for: asset,
targetSize: CGSize(width: 100, height: 100),
contentMode: PHImageContentMode.aspectFill,
options: nil,
resultHandler: handler)
}
}
// MARK:- UICollectionViewDataSource
extension PhotoCollectionViewController {
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
override func collectionView(_ collectionView: UICollectionView,
numberOfItemsInSection section: Int) -> Int {
return self.fetchResult?.count ?? 0
}
}
extension PhotoCollectionViewController {
override func collectionView(_ collectionView: UICollectionView,
cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell: PhotoCollectionViewCell
cell = collectionView.dequeueReusableCell(withReuseIdentifier: self.cellReuseIdentifier,
for: indexPath) as! PhotoCollectionViewCell
return cell
}
override func collectionView(_ collectionView: UICollectionView,
willDisplay cell: UICollectionViewCell,
forItemAt indexPath: IndexPath) {
guard let cell: PhotoCollectionViewCell = cell as? PhotoCollectionViewCell else {
return
}
self.configureCell(cell, collectionView: collectionView, indexPath: indexPath)
}
}
// MARK:- UICollectionViewDelegateFlowLayout
extension PhotoCollectionViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
guard let flowLayout: UICollectionViewFlowLayout =
self.collectionViewLayout as? UICollectionViewFlowLayout else { return CGSize.zero}
let numberOfCellsInRow: CGFloat = 4
let viewSize: CGSize = self.view.frame.size
let sectionInset: UIEdgeInsets = flowLayout.sectionInset
let interitemSpace: CGFloat = flowLayout.minimumInteritemSpacing * (numberOfCellsInRow - 1)
var itemWidth: CGFloat
itemWidth = viewSize.width - sectionInset.left - sectionInset.right - interitemSpace
itemWidth /= numberOfCellsInRow
let itemSize = CGSize(width: itemWidth, height: itemWidth)
return itemSize
}
}
extension PhotoCollectionViewController {
private func updateCollectionView(with changes: PHFetchResultChangeDetails<PHAsset>) {
guard let collectionView = self.collectionView else { return }
// 업데이트는 삭제, 삽입, 다시 불러오기, 이동 순으로 진행합니다
if let removed: IndexSet = changes.removedIndexes, removed.count > 0 {
collectionView.deleteItems(at: removed.map({
IndexPath(item: $0, section: 0)
}))
}
if let inserted: IndexSet = changes.insertedIndexes, inserted.count > 0 {
collectionView.insertItems(at: inserted.map({
IndexPath(item: $0, section: 0)
}))
}
if let changed: IndexSet = changes.changedIndexes, changed.count > 0 {
collectionView.reloadItems(at: changed.map({
IndexPath(item: $0, section: 0)
}))
}
changes.enumerateMoves { fromIndex, toIndex in
collectionView.moveItem(at: IndexPath(item: fromIndex, section: 0),
to: IndexPath(item: toIndex, section: 0))
}
}
}
// MARK:- PHPhotoLibraryChangeObserver
extension PhotoCollectionViewController: PHPhotoLibraryChangeObserver {
private func resetCachedAssets() {
self.cachingImageManager.stopCachingImagesForAllAssets()
}
func photoLibraryDidChange(_ changeInstance: PHChange) {
guard let fetchResult: PHFetchResult<PHAsset> = self.fetchResult
else { return }
guard let changes: PHFetchResultChangeDetails<PHAsset> =
changeInstance.changeDetails(for: fetchResult)
else { return }
DispatchQueue.main.sync {
self.resetCachedAssets()
self.fetchResult = changes.fetchResultAfterChanges
if changes.hasIncrementalChanges {
self.updateCollectionView(with: changes)
} else {
self.collectionView?.reloadSections(IndexSet(0...0))
}
}
}
}
extension PhotoCollectionViewController {
// MARK:- Lifecycle
override func viewDidLoad() {
super.viewDidLoad()
PHPhotoLibrary.shared().register(self)
self.sortButton.title = "In the past"
self.actionButton.isEnabled = false
self.trashButton.isEnabled = false
}
}
AssetCollection can be selected by clicking the select barButtonItem in the upper right corner of the screen, and I want to delete or share selected pictures.

Answer 1

You can perfore delete action on phAsset as below:
PHPhotoLibrary.sharedPhotoLibrary().performChanges({
//Delete Photo
PHAssetChangeRequest.deleteAssets(delShotsAsset)
},
completionHandler: {(success, error)in
NSLog("\nDeleted Image -> %#", (success ? "Success":"Error!"))
if(success){
}else{
println("Error: \(error)")
}
})