/// <summary>
/// Downloads data from ArcGIS Portal and unzips it to the local data folder
/// </summary>
/// <param name="path">The path to put the data in - if the folder already exists, the data is assumed to have been downloaded and this immediately returns</param>
/// <param name="progress">Progress reporr status callback</param>
/// <returns></returns>
public static async Task GetDataAsync(string path, Action <string> progress)
{
if (System.IO.Directory.Exists(path))
{
return;
}
DownloadManager.FileDownloadTask task = null;
string tempFile = null;
if (AppSettings.Contains("DataDownloadTask"))
{
var previousTask = DownloadManager.FileDownloadTask.FromJson(AppSettings.GetValueOrDefault("DataDownloadTask", string.Empty));
if (previousTask.IsResumable)
{
task = previousTask;
tempFile = task.Filename;
}
}
if (task == null)
{
progress?.Invoke("Fetching offline data info...");
var portal = await Esri.ArcGISRuntime.Portal.ArcGISPortal.CreateAsync(new Uri("https://www.arcgis.com/sharing/rest")).ConfigureAwait(false);
var item = await Esri.ArcGISRuntime.Portal.PortalItem.CreateAsync(portal, itemId).ConfigureAwait(false);
progress?.Invoke("Initiating download...");
tempFile = Path.GetTempFileName();
task = await DownloadManager.FileDownloadTask.StartDownload(tempFile, item);
string downloadTask = task.ToJson();
AppSettings.AddOrUpdateValue("DataDownloadTask", task.ToJson());
}
progress?.Invoke("Downloading data...");
if (progress != null)
{
string lastState = "";
task.Progress += (s, e) =>
{
var state = "Downloading data " + (e.HasPercentage ? e.Percentage.ToString() + "%" : e.TotalBytes / 1024 + " kb...");
if (state != lastState)
{
progress?.Invoke(state);
lastState = state;
}
};
}
await task.DownloadAsync();
AppSettings.Remove("DataDownloadTask");
progress?.Invoke("Unpacking data...");
await UnpackData(tempFile, path);
progress?.Invoke("Complete");
}
private static async Task <FileDownloadTask> StartDownload(HttpRequestMessage request, string filename, HttpMessageHandler handler = null)
{
HttpClient client;
if (handler == null)
{
handler = new HttpClientHandler();
}
client = new HttpClient(handler);
var response = await client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead).ConfigureAwait(false);
var content = response.EnsureSuccessStatusCode();
FileDownloadTask result = new FileDownloadTask(filename, request.RequestUri, content, client);
return(result);
}
