我有一个显示图像的 Collection View ,其中一些被缓存并正确检索,但其他则没有。 Collection View 每行显示两个方形单元格。
我不明白为什么有时图像是从缓存中获取的,而其他时候必须重新下载。
这里是我缓存图片的地方:
class DataImage {
static let sharedManager = DataImage()
let decoder = ImageDecoder()
let photoCache = AutoPurgingImageCache(
memoryCapacity: 100 * 1024 * 1024,
preferredMemoryUsageAfterPurge: 60 * 1024 * 1024
)
//MARK: - Image Downloading
func getNetworkImage(urlString: String, completion: (UIImage -> Void)) -> (ImageRequest) {
let queue = decoder.queue.underlyingQueue
let request = Alamofire.request(.GET, urlString)
let imageRequest = ImageRequest(request: request)
imageRequest.request.response(
queue: queue,
responseSerializer: Request.imageResponseSerializer(),
completionHandler: { response in
guard let image = response.result.value else {
return
}
let decodeOperation = self.decodeImage(image) { image in
completion(image)
self.cacheImage(image, urlString: urlString)
}
imageRequest.decodeOperation = decodeOperation
}
)
return imageRequest
}
func decodeImage(image: UIImage, completion: (UIImage -> Void)) -> DecodeOperation {
let decodeOperation = DecodeOperation(image: image, decoder: self.decoder, completion: completion)
self.decoder.queue.addOperation(decodeOperation)
return decodeOperation
}
//MARK: - Image Caching
func cacheImage(image: Image, urlString: String) {
photoCache.addImage(image, withIdentifier: urlString)
}
func cachedImage(urlString: String) -> Image? {
print("image: \(photoCache.imageWithIdentifier(urlString))")
return photoCache.imageWithIdentifier(urlString)
}
这是 Cell 类:
class StoreCell: UICollectionViewCell {
@IBOutlet weak var title: UILabel!
@IBOutlet weak var storyImage: UIImageView!
@IBOutlet weak var subTitle: UILabel!
@IBOutlet weak var cost: UILabel!
var imageFilename: String!
var request: ImageRequest!
var dataImage = DataImage()
func configure() {
self.layer.cornerRadius = 3.0
reset()
loadImage()
}
func reset() {
storyImage.image = nil
request?.cancel()
}
func loadImage() {
let stringURL = "https://........\(imageFilename)"
if self.storyImage.image == nil {
if let image = dataImage.cachedImage(stringURL) {
self.storyImage.image = image
} else {
request = dataImage.getNetworkImage(stringURL) { image in
self.storyImage.image = image
self.storyImage.runImageTransition(.CrossDissolve(0.2), withImage: image)
}
}
}
}
最佳答案
我将在下面分享所有代码。
首先您需要更新 ImageRequest 类
import UIKit
import Alamofire
class ImageRequest {
var decodeOperation: Operation?
var request: DataRequest
init(request: DataRequest) {
self.request = request
}
func cancel() {
decodeOperation?.cancel()
request.cancel()
}
}
第二个
import UIKit
import Alamofire
import AlamofireImage
class DataImage {
static let sharedManager = DataImage()
let decoder = ImageDecoder()
let photoCache = AutoPurgingImageCache(
memoryCapacity: 100 * 1024 * 1024,
preferredMemoryUsageAfterPurge: 60 * 1024 * 1024
)
//MARK: - Read Data
func allPhotos() -> [GlacierScenic] {
if !photos.isEmpty { return photos }
guard let data = NSArray(contentsOfFile: dataPath()) as? [NSDictionary] else { return photos }
for photoInfo in data {
let name = photoInfo["name"] as! String
let urlString = photoInfo["imageURL"] as! String
let glacierScenic = GlacierScenic(name: name, photoURLString: urlString)
photos.append(glacierScenic)
}
return photos
}
func dataPath() -> String {
return Bundle.main.path(forResource: "GlacierScenics", ofType: "plist")!
}
//MARK: - Image Downloading
func getNetworkImage(urlString: String, completion: @escaping ((UIImage) -> Void)) -> (ImageRequest) {
let queue = decoder.queue.underlyingQueue
let request = Alamofire.request(urlString)
let imageRequest = ImageRequest(request: request)
imageRequest.request.response(
queue: queue,
responseSerializer: DataRequest.imageResponseSerializer(),
completionHandler: { response in
guard let image = response.result.value else {
return
}
let decodeOperation = self.decodeImage(image) { image in
completion(image)
self.cacheImage(image, urlString: urlString)
}
imageRequest.decodeOperation = decodeOperation
}
)
return imageRequest
}
func decodeImage(_ image: UIImage, completion: @escaping ((UIImage) -> Void)) -> DecodeOperation {
let decodeOperation = DecodeOperation(image: image, decoder: self.decoder, completion: completion)
self.decoder.queue.addOperation(decodeOperation)
return decodeOperation
}
//MARK: - Image Caching
func cacheImage(_ image: Image, urlString: String) {
photoCache.add(image, withIdentifier: urlString)
}
func cachedImage(_ urlString: String) -> Image? {
return photoCache.image(withIdentifier: urlString)
}
}
第三个
我的 pod 文件详细信息。
source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '10.0'
use_frameworks!
target 'projetname' do
pod 'Alamofire', :git => 'https://github.com/Alamofire/Alamofire.git', :tag => '4.0.0'
pod 'AlamofireImage', :git => 'https://github.com/Alamofire/AlamofireImage.git', :tag => '3.1.0'
end
post_install do |installer|
installer.pods_project.targets.each do |target|
target.build_configurations.each do |config|
config.build_settings['SWIFT_VERSION'] = '3.0'
end
end
end
关于ios - 使用 alamofireimages 缓存,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/39057081/