Swift - comment obtenir le dernier pris 3 photos à partir de photos de la bibliothèque?

Voici une solution à l'aide de la Photos le cadre est disponible pour les appareils iOS 8+ :

import Photos
class ViewController: UIViewController {
var images:[UIImage] = []
func fetchPhotos () {
//Sort the images by descending creation date and fetch the first 3
        let fetchOptions = PHFetchOptions()
fetchOptions.sortDescriptors = [NSSortDescriptor(key:"creationDate", ascending: false)]
fetchOptions.fetchLimit = 3
//Fetch the image assets
        let fetchResult: PHFetchResult = PHAsset.fetchAssets(with: PHAssetMediaType.image, options: fetchOptions)
//If the fetch result isn't empty,
        //proceed with the image request
        if fetchResult.count > 0 {
let totalImageCountNeeded = 3 //<-- The number of images to fetch
            fetchPhotoAtIndex(0, totalImageCountNeeded, fetchResult)
}
}
//Repeatedly call the following method while incrementing
    //the index until all the photos are fetched
    func fetchPhotoAtIndex(_ index:Int, _ totalImageCountNeeded: Int, _ fetchResult: PHFetchResult<PHAsset>) {
//Note that if the request is not set to synchronous
        //the requestImageForAsset will return both the image
        //and thumbnail; by setting synchronous to true it
        //will return just the thumbnail
        let requestOptions = PHImageRequestOptions()
requestOptions.isSynchronous = true
//Perform the image request
        PHImageManager.default().requestImage(for: fetchResult.object(at: index) as PHAsset, targetSize: view.frame.size, contentMode: PHImageContentMode.aspectFill, options: requestOptions, resultHandler: { (image, _) in
if let image = image {
//Add the returned image to your array
                self.images += [image]
}
//If you haven't already reached the first
            //index of the fetch result and if you haven't
            //already stored all of the images you need,
            //perform the fetch request again with an
            //incremented index
            if index + 1 < fetchResult.count && self.images.count < totalImageCountNeeded {
self.fetchPhotoAtIndex(index + 1, totalImageCountNeeded, fetchResult)
} else {
//Else you have completed creating your array
                print("Completed array: \(self.images)")
}
})
}
}

Vous pouvez extraire les 3 dernières photos à l'aide de fonctions dans le AssetsLibrary cadre. Vous devez d'abord ajouter le cadre du projet. La fonction suivante récupère les 3 dernières photos et des appels à la fin du bloc.

import AssetsLibrary
func getLatestPhotos(completion completionBlock : ([UIImage] -> ()))   {
let library = ALAssetsLibrary()
var count = 0
var images : [UIImage] = []
var stopped = false
library.enumerateGroupsWithTypes(ALAssetsGroupSavedPhotos, usingBlock: { (group,var stop) -> Void in
group?.setAssetsFilter(ALAssetsFilter.allPhotos())
group?.enumerateAssetsWithOptions(NSEnumerationOptions.Reverse, usingBlock: {
(asset : ALAsset!, index, var stopEnumeration) -> Void in
if (!stopped)
{
if count >= 3
{
stopEnumeration.memory = ObjCBool(true)
stop.memory = ObjCBool(true)
completionBlock(images)
stopped = true
}
else
{
//For just the thumbnails use the following line.
                    let cgImage = asset.thumbnail().takeUnretainedValue()
//Use the following line for the full image.
                    let cgImage = asset.defaultRepresentation().fullScreenImage().takeUnretainedValue()
if let image = UIImage(CGImage: cgImage) {
images.append(image)
count += 1
}
}
}
})
},failureBlock : { error in
println(error)
})
}

La fonction ci-dessus peut être appelée comme cela

getLatestPhotos(completion: { images in
println(images)
//Set Images in this block.
})