UnityEditor.AssetStoreUtils.CheckDownload C# (CSharp) Method

        public static extern string CheckDownload(string id, string url, string[] destination, string key);
        [ExcludeFromDocs]

        public static void Download(string package_id, string url, string key, string package_name,
                                    string publisher_name, string category_name, AssetStoreUtils.DownloadDoneCallback doneCallback)
        {
            string[] dest = PackageStorePath(publisher_name, category_name,
                                             package_name, package_id, url);

            JSONValue existing = JSONParser.SimpleParse(AssetStoreUtils.CheckDownload(package_id, url, dest, key));

            // If the package is actively being downloaded right now just return
            if (existing.Get("in_progress").AsBool(true))
            {
                Debug.Log("Will not download " + package_name + ". Download is already in progress.");
                return;
            }

            // The package is not being downloaded.
            // If the package has previously been partially downloaded then
            // resume that download.
            string existingUrl = existing.Get("download.url").AsString(true);
            string existingKey = existing.Get("download.key").AsString(true);
            bool   resumeOK    = (existingUrl == url && existingKey == key);

            JSONValue download = new JSONValue();

            download["url"] = url;
            download["key"] = key;
            JSONValue parameters = new JSONValue();

            parameters["download"] = download;

            AssetStoreUtils.Download(package_id, url, dest, key, parameters.ToString(), resumeOK, doneCallback);
        }