从 URL Swift 解压 NSData 文件夹 [英] Unzip NSData folder from URL Swift

问题描述

以下代码适用于从 url 下载单个图像.

The code below works for downloading a single image from a url.

    func imageForImageURLString(imageURLString: String, completion: (image: UIImage?, success: Bool) -> Void) {
    guard let url = NSURL(string: imageURLString),
        let data = NSData(contentsOfURL: url),
        let image = UIImage(data: data)
        else {
            completion(image: UIImage(named:"absolut5.png"), success: false);
            return
    }
    completion(image: image, success: true)
}

然而，我使用的一些 url 是一个压缩文件夹，里面有几个 png 文件.所以我调整了上面的代码，只带回数据.这似乎有效

however some of the urls I am working with are a zipped folder with several png files inside. So I have adjusted the above code to just bring back the data. Which seems to work

func dataForDataURLString(imageURLString: String, completion: (data: NSData?, success: Bool) -> Void) {
    guard let url = NSURL(string: imageURLString),
        let data = NSData(contentsOfURL: url)
        else {
            return
    }
    completion(data: data, success: true)
}

使用

let imageUrlString = item.valueForKey(url) as! String
self.dataForDataURLString(imageUrlString, completion: { (data, success) -> Void in
    if success {
       guard let dataDocs = data
          else { return } // Error handling here
            documentData = dataDocs
      } else {
          // Error handling here.
      }
    })

但是我没有找到任何可以解压缩/循环返回数据内容的内容.它不是 JSON 格式，只是打印时数字的原始数据字符串.

But I have not found anything to unzip/loop through the contents of the returned data. It is not in a JSON format, just raw data strings of numbers when printed.

任何帮助将不胜感激(可能值得一提的是，我正在后台 NSOperationQueue 中执行所有这些操作，完成块将结果保存在核心数据中.我查看了一些 NSURLSessionDownloadTask 选项，但这些似乎继续一个不同的线程，但仍然不起作用)

Any help would be appreciated (it is probably worth mentioning that I am doing all this in a background NSOperationQueue with the completion block saving the result in core data. I have looked at a few NSURLSessionDownloadTask options, but these seem to go onto a different thread, and still don't work)

推荐答案

只是为了发布我使用的解决方案

just to post the solution I went with

func unzipData(objectData: NSManagedObject) {
    var paths = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
    let documentsDir = paths[0]
    let zipPath = documentsDir.stringByAppendingString("MyZipFiles")
    let folderPath = documentsDir.stringByAppendingString("/docLibFiles") // My folder name in document directory
    var optData = NSData(data: objectData.valueForKey("image") as! NSData)
    print(objectData.valueForKey("imageUrl") as! String)
    optData.writeToFile(zipPath, atomically: true)
    let success = fileManager.fileExistsAtPath(zipPath) as Bool
    if success == false {
        do {
            try! fileManager.createDirectoryAtPath(folderPath, withIntermediateDirectories: true, attributes: nil)
        }
    }
    queue.addOperationWithBlock { () -> Void in
        let operation1 = NSBlockOperation(block: {
            let unZipped = SSZipArchive.unzipFileAtPath(zipPath, toDestination: folderPath)

        })
        operation1.completionBlock = {
            if queue.operationCount == 0 {
                dispatch_async(dispatch_get_main_queue(), {
                    if queue.operationCount == 0 {
                        self.retrieveFiles()
                    }
                })
            }
        }
        queue.addOperation(operation1)

    }
}

func getDocumentsURL() -> NSURL {
    let documentsURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
    return documentsURL
}

func fileInDocumentsDirectory(filename: String) -> String {
    let fileURL = getDocumentsURL().URLByAppendingPathComponent(filename)
    return fileURL.path!
}

func retrieveFiles() {
    var paths = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
    let documentsDir = paths[0]
    let zipPath = documentsDir.stringByAppendingString("MyZipFiles")
    let folderPath = documentsDir.stringByAppendingString("/docLibFiles") // My folder name in document directory
    do {
        let filelist = try fileManager.contentsOfDirectoryAtPath(folderPath)
        print(filelist)
        print("filename")
        for filename in filelist {

            fileNameArray.append(filename)
        }
    } catch let error as NSError  {
        print("Could not save \(error)")
    }
    do {
        for item in fileNameArray {
            print("item \(item)")
            let imagePath = fileInDocumentsDirectory("docLibFiles/\(item)")
            imageArray.append(UIImage(contentsOfFile: imagePath)!)
        }
        print("filename array \(fileNameArray)")
        print("image array \(imageArray)")
        unzipDelegate!.unzipSet(imageArray)
    }
}

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