Backgrounddownloader sample

When operations are restarted, they might have to discard previously downloaded bytes and therefore the number of bytes downloaded might not always increase from one report to the next. Whenever new response information is available due to a new request being invoked, this field is set to true.

The application can then choose to read the new response information and update its state, if needed. When a download is interrupted and a new request is sent to the server to resume the download, HasRestarted is set to true if the server does not support resume and the download had to start over.

HasRestarted is set to true only in the first progress notification sent after the restart. After the first progress notification, HasRestarted is set to false in later notifications. A BackgroundTransferStatus containing the current status of the download operation. The Overflow Blog. Podcast Making Agile work for data science.

Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. Related Hot Network Questions. Question feed. Then other methods on the BackgroundDownloader and related classes are used to start new downloads to the local Pictures Library. The sample also shows how to pause downloads and change the priority of a download.

For the upload scenario, the sample first uses methods on BackgroundUploader class to enumerate any uploads that were going on in the background while the app was closed.

An app should enumerate these uploads when it gets started so it can attach a progress handler to these uploads to track progress and prevent stale uploads. Then other methods on the BackgroundUploader and related classes are used to start new uploads.

The sample also shows how to set a content header and use a multipart upload. Note Background transfer is primarily designed for long-term transfer operations for resources like video, music, and large images.

For short-term operations involving transfers of smaller resources i. HttpClient is preferred and can be used in all languages supported by UWP apps. XHR can be used in JavaScript. For more information on network capabilities, see How to set network capabilities. Note Network communications using an IP loopback address cannot normally be used for interprocess communication between a UWP app and a different process a different UWP app or a desktop app because this is restricted by network isolation.

When using Background Transfer during development, you may get into a situation where the internal caches of active and completed transfer operations can get out of sync. This may result in the inability to start new transfer operations or interact with existing operations and BackgroundTransferGroup objects. In some cases, attempting to interact with existing operations may trigger a crash.

This result can occur if the TransferBehavior property is set to Parallel. This issue occurs only in certain scenarios during development and is not applicable to end users of your app. To work around this issue, completely uninstall all versions of the app and re-deploy with the new language, architecture, culture, or capability. Creates a new BackgroundDownloader object. Gets or sets the TileNotification used to define the visuals, identification tag, and expiration time of a tile notification used to update the app tile when indicating failure of a download to the user.

Gets or sets the ToastNotification that defines the content, associated metadata, and events used in a toast notification to indicate failure of a download to the user. Group may be altered or unavailable for releases after Windows 8.

Instead, use TransferGroup. Gets or sets a string value for example, a GUID indicating the group the transfer will belong to. A download operation with a group ID will only appear in operation enumerations using GetCurrentDownloadsAsync String with the specific group string value.

Gets or sets the HTTP method used for the background download. The default method used for download operations is GET. Gets or sets the TileNotification used to define the visuals, identification tag, and expiration time of a tile notification used to update the app tile when indicating success of a download to the user. Gets or sets the ToastNotification that defines the content, associated metadata, and events used in a toast notification to indicate success of a download to the user.

Initializes a DownloadOperation object that contains the specified Uri and the file that the response is written to. Initializes a DownloadOperation object with the resource Uri , the file that the response is written to, and the request entity body. Creates an asynchronous download operation that includes a URI, the file that the response will be written to, and the IInputStream object from which the file contents are read.

Returns a collection of pending downloads that are not associated with a BackgroundTransferGroup. GetCurrentDownloadsAsync group may be altered or unavailable for releases after Windows 8. Returns a collection of pending downloads for a specific Group. Gets all downloads associated with the provided BackgroundTransferGroup.

RequestUnconstrainedDownloadsAsync may be altered or unavailable for releases after Windows 10, version Instead, use CreateDownloadAsync.