WP8后台上传文件到skydrive

Question

我正在开发Windows Phone 8 应用程序，它从电话 收集联系人并将其存储在xml 文件中。我想在background 中将upload 发送给skydrive。我试过这个

IsolatedStorageFileStream fileStream = null;
using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication())
{
    fileStream = store.OpenFile("XMLFile1.xml", FileMode.Open, FileAccess.Read);
    var res = await client.UploadAsync("me/skydrive", "XMLFile1.xml", fileStream, OverwriteOption.Overwrite);
    fileStream.Close();
}

此代码完美运行。但是当我按主页键上传停止。那么即使用户按screen lock key 或home key，我如何在后台将文件上传到skydrive？并且还想知道如何我可以将文件上传到跳伞中的特定文件夹？文件夹，如文档或图片。如何使用client.BackgroundUploadAsync？如何传递fileStream 对象？

Answer 1

您正在使用 UploadAsync，并在您离开应用程序时取消。因为当您点击 StartButton 时，您正在离开您的应用程序并作为 MSDN says:

When the user navigates forward, away from an app, after the Deactivated event is raised, the operating system will attempt to put the app into a dormant state. In this state, all of the application’s threads are stopped and no processing takes place, but the application remains intact in memory.

因此，您的 App 会收到 Deactivation 事件，并且所有线程和任务都已停止。如果您留在您的应用程序中，一切都应该可以正常工作（因为它是异步的）。

编辑 - 使用 Background Transfers 可以在后台下载

正如您所发现的，有一种方法 BackgroundUploadAsync，正如那里所说：

Begins uploading a file from Windows Phone isolated storage to Microsoft SkyDrive. The file upload should continue even if the app that starts the file upload quits or is suspended.

允许从/到目录 shared/transfers/ 下载/上传文件（仅此 - 所以在您上传之前，您的文件必须复制到那里）。非常简单的代码可以是这样的——开始异步上传：

client.BackgroundTransferPreferences = BackgroundTransferPreferences.None; // check policies for this - with this you have to have your phone powered by external source and use WiFi
try
{
   client.BackgroundUploadAsync("me/skydrive", new Uri("shared/transfers/sample.txt", UriKind.Relative), OverwriteOption.Overwrite);
}
catch { }

但您必须知道，后台传输有其自己的policies - 您应该在发布之前对您的应用进行严格测试。

希望这会有所帮助。

Answer 2

使用此 OneDriveChunkedUpload.cs 上传大文件 https://gist.github.com/ificator/3460d7b9d0bff74eb0ff

Answer 3

此 PostCompleted 事件用于在 skydrive 中上传您的文件：

client.PostCompleted +=
                        new EventHandler<LiveOperationCompletedEventArgs>(CreateMyFolder_Completed);
 void CreateMyFolder_Completed(object sender, LiveOperationCompletedEventArgs e)
        {
            if (e.Error == null)
            {
               string folderID = (e.Result["id"]).ToString();
                foreach (string item in names)
                {
                    using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication())
                    {
                        string filename = item;
                        if (store.FileExists(filename))
                        {
                            IsolatedStorageFileStream storeStream = store.OpenFile(filename, FileMode.Open, FileAccess.Read);
                            client.UploadAsync(folderID, filename, storeStream, OverwriteOption.Overwrite);

                        }                         
                    }
                }
            }