BackgroundDownloader BackgroundDownloader BackgroundDownloader BackgroundDownloader Class

Used to configure downloads prior to the actual creation of the download operation using CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.IStorageFile). For an overview of Background Transfer capabilities, see Transferring data in the background. Download the Background Transfer sample for examples in JavaScript, C#, and C++.

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.e. a couple KB), use the Windows.Web.Http namespace.

Syntax

Declaration

public sealed class BackgroundDownloaderpublic sealed class BackgroundDownloaderPublic NotInheritable Class BackgroundDownloader

Remarks

After app termination, an app should enumerate all existing DownloadOperation instances at next start-up using GetCurrentDownloadsAsync(). When a Windows Store app using Background Transfer is terminated, incomplete downloads will persist in the background. If the app is restarted after termination and operations from the previous session are not enumerated and re-attached to the current session, they will remain incomplete and continue to occupy resources.

Note

When an app is uninstalled any current or persisted Background Transfer operations associated with it are cleaned up.

Background transfer doesn't support concurrent downloads of the same Uri. So an app can download http://example.com/myfile.wmv once, or download it again after a previous download completed. An app shouldn't start two downloads of the same Uri concurrently, since this may result in truncated files.

When implementing a library for Background Transfer operations, and this same library is used by other apps or components, specify a uniquegroup name string (e.g. a GUID) when creating downloads. An download with a group name string can only be enumerated by providing the matching string to GetCurrentDownloadsAsync(System.String), and will not appear in GetCurrentDownloadsAsync() calls without. This will ensure that other apps implementing that same library for downloads will not see your downloads.

Download operations via FTP are supported. However, for FTP operations, authentication credentials must be provided within the specified URI. For example, ftp://user:password@server/file.txt.

Security concerns can exist when download operations require a username and password for authentication. If the authentication model to be used is supported by WinINet, use the ServerCredential or ProxyCredential properties. These values will be securely saved in WinVault. For information on supported authentication methods, see Handling Authentication.

If the authentication model is not supported by WinINet, use HttpClient to implement custom authentication and obtain a download-specific secure token (cookie). Set the appropriate header to have the secure token value used for background transfer. The service should limit the validity of the secure token only to the file that is being downloaded.

Note

The secure token will be stored in clear text within the application’s folder.

Upload services that require the username and password be set in clear text in a custom header for each download file are insecure. Background transfer will cache the headers in clear text for the duration of the operation within the app’s folder.

Toast notifications

The BackgroundDownloader class in Windows 8.1 and Windows Server 2012 R2 supports options for the user to receive tile and toast notifications when a transfer is completed successfully or fails to complete.

An app that uses Windows.Networking.BackgroundTransfer to communicate through a toast notification must declare that it is Toast capable in the app manifest file. The Toast capable setting is located under the Notifications section of Application tab. Set the Toast capable option to "Yes" so the app can receive toast notifications.

If Toast capable is not enabled in the app manifest, then any toast settings in the Windows.Networking.BackgroundTransfer namespace will be silently ignored and no toasts notifications will be received by the app.

Note

A user can manually disable or enable toast notifications for your app at any time.

For more information on toast notifications, see Sending toast notifications and How to opt in for toast notifications.

Handling exceptions

A number of errors can cause exceptions to occur during a download operation. You should write code to handle exceptions when you call methods on this class. Exceptions can result from parameter validation errors, name resolution failures, and network errors. Exceptions from network errors (loss of connectivity, connection failures, and other HTTP errors, for example) can happen at any time. These errors result in exceptions being thrown. If not handled by your app, an exception can cause your entire app to be terminated by the runtime.

An app can use the HRESULT from the exception to determine the error that caused the exception. An app can then decide how to handle the exception based on the error code. The GetStatus(System.Int32) method can convert most HRESULT values returned to a WebErrorStatus enumeration value. Most of the WebErrorStatus enumeration values correspond to an error returned by the native HTTP or FTP client operation. An app can filter on specific WebErrorStatus enumeration values to modify app behavior depending on the cause of the exception.

For information on network exceptions, see Handling exceptions in network apps.

Debugging Guidance

Stopping a debugging session in Microsoft Visual Studio is comparable to closing your app. Even while debugging, your app should enumerate and then, resume, restart, or cancel any downloads persisted from the previous session. For example, you can have your app cancel enumerated persisted download operations at app startup if there is no interest in previous operations for the current debug session.

If there are Microsoft Visual Studio project updates, like changes to the app manifest, and the app is uninstalled and re-deployed, GetCurrentUploadsAsync() cannot enumerate operations created using the previous app deployment.

See Debugging and testing Windows Store apps for more information.

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.

Four scenarios using Microsoft Visual Studio can cause this issue.

  • You create a new project with the same app name as an existing project, but a different language (from C++ to C#, for example).
  • You change the target architecture (from x86 to x64, for example) in an existing project.
  • You change the culture (from neutral to en-US, for example) in an existing project.
  • You add or remove a capability in the package manifest (adding Enterprise Authentication, for example) in an existing project. Regular app servicing, including manifest updates which add or remove capabilities, do not trigger this issue on end user deployments 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. This can be done via the Start screen or using PowerShell and the Remove-AppxPackage cmdlet.

Examples

The following example demonstrates how to configure and begin a basic download operation, and is based on the Background Transfer sample offered in the Windows Sample Gallery.

        var download = null;
        var promise = null;

        function DownloadFile (uriString, fileName) {
            try {
                // Asynchronously create the file in the pictures folder.
                Windows.Storage.KnownFolders.picturesLibrary.createFileAsync(fileName, Windows.Storage.CreationCollisionOption.generateUniqueName).done(function (newFile) {
                    var uri = Windows.Foundation.Uri(uriString);
                    var downloader = new Windows.Networking.BackgroundTransfer.BackgroundDownloader();

                    // Create a new download operation.
                    download = downloader.createDownload(uri, newFile);

                    // Start the download and persist the promise to be able to cancel the download.
                    promise = download.startAsync().then(complete, error, progress);
                }, error);
            } catch (err) {
                displayException(err);
            }
        };

       using Windows.Foundation;
       using Windows.Networking.BackgroundTransfer;
       using Windows.Storage;

       private async void StartDownload_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                Uri source = new Uri(serverAddressField.Text.Trim());
                string destination = fileNameField.Text.Trim();

                StorageFile destinationFile = await KnownFolders.PicturesLibrary.CreateFileAsync(
                    destination, CreationCollisionOption.GenerateUniqueName);

                BackgroundDownloader downloader = new BackgroundDownloader();
                DownloadOperation download = downloader.CreateDownload(source, destinationFile);

                // Attach progress and completion handlers.
                HandleDownloadAsync(download, true);
            }
            catch (Exception ex)
            {
                LogException("Download Error", ex);
            }
        }

Constructors summary

Creates a new BackgroundDownloader object.

Creates a new BackgroundDownloader object with a BackgroundTransferCompletionGroup.

Properties summary

Gets the BackgroundTransferCompletionGroup associated with the BackgroundDownloader.

Gets or sets the cost policy for the background download operation.

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.

Note

Group may be altered or unavailable for releases after Windows 8.1. Instead, use TransferGroup.

Gets or sets a string value (e.g. 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(System.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 proxy credentials for the background transfer.

Gets or sets the credentials to use to authenticate with the origin server.

Note

For downloads via FTP, authentication credentials must be provided within the specified URI. For example, ftp://user:password@server/file.txt.

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.

Gets or sets the group that a download operation will belong to.

Methods summary

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.

Returns a collection of pending downloads for a specific Group.

Gets all downloads associated with the provided BackgroundTransferGroup.

Used to request an unconstrained download operation. When this method is called the user is provided with a UI prompt that they can use to indicate their consent for an unconstrained operation.An unconstrained transfer operation will run without the resource restrictions normally associated with background network operations while a device is running on battery.

Used to set an HTTP request header.

Constructors

Properties

  • CompletionGroup
    CompletionGroup
    CompletionGroup
    CompletionGroup

    Gets the BackgroundTransferCompletionGroup associated with the BackgroundDownloader.

    public BackgroundTransferCompletionGroup CompletionGroup { get; }public BackgroundTransferCompletionGroup CompletionGroup { get; }Public ReadOnly Property CompletionGroup As BackgroundTransferCompletionGroup

    Property Value

  • CostPolicy
    CostPolicy
    CostPolicy
    CostPolicy

    Gets or sets the cost policy for the background download operation.

    public BackgroundTransferCostPolicy CostPolicy { get; set; }public BackgroundTransferCostPolicy CostPolicy { get; set; }Public ReadWrite Property CostPolicy As BackgroundTransferCostPolicy

    Property Value

  • FailureTileNotification
    FailureTileNotification
    FailureTileNotification
    FailureTileNotification

    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.

    public TileNotification FailureTileNotification { get; set; }public TileNotification FailureTileNotification { get; set; }Public ReadWrite Property FailureTileNotification As TileNotification

    Property Value

  • FailureToastNotification
    FailureToastNotification
    FailureToastNotification
    FailureToastNotification

    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.

    public ToastNotification FailureToastNotification { get; set; }public ToastNotification FailureToastNotification { get; set; }Public ReadWrite Property FailureToastNotification As ToastNotification

    Property Value

    Remarks

    An app that uses Windows.Networking.BackgroundTransfer to communicate through a toast notification must declare that it is Toast capable in the app manifest file. The Toast capable setting is located under the Notifications section of Application tab. Set the Toast capable option to "Yes" so the app can receive toast notifications.

    If Toast capable is not enabled in the app manifest, then any toast settings in the Windows.Networking.BackgroundTransfer namespace will be silently ignored and no toasts notifications will be received by the app.

    Note

    A user can manually disable or enable toast notifications for your app at any time.

    For more information on toast notifications, see Sending toast notifications and How to opt in for toast notifications.

  • Group
    Group
    Group
    Group
    Note

    Group may be altered or unavailable for releases after Windows 8.1. Instead, use TransferGroup.

    Gets or sets a string value (e.g. 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(System.String) with the specific group string value.

    public string Group { get; set; }public string Group { get; set; }Public ReadWrite Property Group As string

    Property Value

    • string
      string
      string
      string

      The group name.

  • Method
    Method
    Method
    Method

    Gets or sets the HTTP method used for the background download. The default method used for download operations is GET.

    public string Method { get; set; }public string Method { get; set; }Public ReadWrite Property Method As string

    Property Value

    • string
      string
      string
      string

      The method to use for the background download. Setting this property will override the default method used for the operation.

  • ProxyCredential
    ProxyCredential
    ProxyCredential
    ProxyCredential

    Gets or sets the proxy credentials for the background transfer.

    public PasswordCredential ProxyCredential { get; set; }public PasswordCredential ProxyCredential { get; set; }Public ReadWrite Property ProxyCredential As PasswordCredential

    Property Value

  • ServerCredential
    ServerCredential
    ServerCredential
    ServerCredential

    Gets or sets the credentials to use to authenticate with the origin server.

    Note

    For downloads via FTP, authentication credentials must be provided within the specified URI. For example, ftp://user:password@server/file.txt.

    public PasswordCredential ServerCredential { get; set; }public PasswordCredential ServerCredential { get; set; }Public ReadWrite Property ServerCredential As PasswordCredential

    Property Value

  • SuccessTileNotification
    SuccessTileNotification
    SuccessTileNotification
    SuccessTileNotification

    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.

    public TileNotification SuccessTileNotification { get; set; }public TileNotification SuccessTileNotification { get; set; }Public ReadWrite Property SuccessTileNotification As TileNotification

    Property Value

  • SuccessToastNotification
    SuccessToastNotification
    SuccessToastNotification
    SuccessToastNotification

    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.

    public ToastNotification SuccessToastNotification { get; set; }public ToastNotification SuccessToastNotification { get; set; }Public ReadWrite Property SuccessToastNotification As ToastNotification

    Property Value

    Remarks

    An app that uses Windows.Networking.BackgroundTransfer to communicate through a toast notification must declare that it is Toast capable in the app manifest file. The Toast capable setting is located under the Notifications section of Application tab. Set the Toast capable option to "Yes" so the app can receive toast notifications.

    If Toast capable is not enabled in the app manifest, then any toast settings in the Windows.Networking.BackgroundTransfer namespace will be silently ignored and no toasts notifications will be received by the app.

    Note

    A user can manually disable or enable toast notifications for your app at any time.

    For more information on toast notifications, see Sending toast notifications and How to opt in for toast notifications.

  • TransferGroup
    TransferGroup
    TransferGroup
    TransferGroup

    Gets or sets the group that a download operation will belong to.

    public BackgroundTransferGroup TransferGroup { get; set; }public BackgroundTransferGroup TransferGroup { get; set; }Public ReadWrite Property TransferGroup As BackgroundTransferGroup

    Property Value

Methods

  • CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile)
    CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile)
    CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile)
    CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile)

    Initializes a DownloadOperation object that contains the specified Uri and the file that the response is written to.

    public DownloadOperation CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile)public DownloadOperation CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile)Public Function CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile) As DownloadOperation

    Parameters

    Returns

    Remarks

    Background transfer doesn't support concurrent downloads of the same Uri. So an app can download http://example.com/myfile.wmv once, or download it again after a previous download completed. An app shouldn't start two downloads of the same Uri concurrently, since this may result in truncated files.

    Important

    Creating a large number of transfers on the main UI thread with CreateDownload can result in degraded performance of your app's UI. If you are queuing up a large number of transfers, it is recommended that you call CreateDownload on a background worker thread as in the following example.

    operation = await Task.Run(() => { return myDownloader.CreateDownload(uri, file); });
    
  • CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.IStorageFile)
    CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.IStorageFile)
    CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.IStorageFile)
    CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.IStorageFile)

    Initializes a DownloadOperation object with the resource Uri, the file that the response is written to, and the request entity body.

    public DownloadOperation CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.IStorageFile)public DownloadOperation CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.IStorageFile)Public Function CreateDownload(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.IStorageFile) As DownloadOperation

    Parameters

    Returns

    Remarks

    The resultant DownloadOperation supports scenarios where a valid download request contains specific data required by the server. For example, a website requires a filled out form before the download can take place.

    Background transfer doesn't support concurrent downloads of the same Uri. So an app can download http://example.com/myfile.wmv once, or download it again after a previous download completed. An app shouldn't start two downloads of the same Uri concurrently, since this may result in truncated files.

    Important

    Creating a large number of transfers on the main UI thread with CreateDownload can result in degraded performance of your app's UI. If you are queuing up a large number of transfers, it is recommended that you call CreateDownload on a background worker thread as in the following example.

    operation = await Task.Run(() => { return myDownloader.CreateDownload(uri, file); });
    
  • CreateDownloadAsync(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.Streams.IInputStream)
    CreateDownloadAsync(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.Streams.IInputStream)
    CreateDownloadAsync(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.Streams.IInputStream)
    CreateDownloadAsync(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.Streams.IInputStream)

    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.

    public IAsyncOperation<DownloadOperation> CreateDownloadAsync(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.Streams.IInputStream)public IAsyncOperation<DownloadOperation> CreateDownloadAsync(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.Streams.IInputStream)Public Function CreateDownloadAsync(Windows.Foundation.Uri,Windows.Storage.IStorageFile,Windows.Storage.Streams.IInputStream) As IAsyncOperation( Of DownloadOperation )

    Parameters

    Returns

    • The resultant asynchronous download operation.

    Remarks

    Background transfer doesn't support concurrent downloads of the same Uri. So an app can download http://example.com/myfile.wmv once, or download it again after a previous download completed. An app shouldn't start two downloads of the same Uri concurrently, since this may result in truncated files.

  • GetCurrentDownloadsAsync()
    GetCurrentDownloadsAsync()
    GetCurrentDownloadsAsync()
    GetCurrentDownloadsAsync()

    Returns a collection of pending downloads that are not associated with a BackgroundTransferGroup.

    public static IAsyncOperation<DownloadOperation>> GetCurrentDownloadsAsync()public static IAsyncOperation<DownloadOperation>> GetCurrentDownloadsAsync()Public Static Function GetCurrentDownloadsAsync() As IAsyncOperation( Of DownloadOperation )

    Returns

    • A collection of pending downloads for the current application instance.

    Remarks

    On Windows Phone, this method will return the error code HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG) if the Internet capability is not declared in your app manifest. On Windows, this method will return the error code HRESULT: 0x80070005 (E_ACCESSDENIED) if the Internet capability is not declared in your app manifest. This capability is enabled by default in all Store app project templates.

  • GetCurrentDownloadsAsync(System.String)
    GetCurrentDownloadsAsync(System.String)
    GetCurrentDownloadsAsync(System.String)
    GetCurrentDownloadsAsync(System.String)

    Returns a collection of pending downloads for a specific Group.

    public static IAsyncOperation<DownloadOperation>> GetCurrentDownloadsAsync(System.String)public static IAsyncOperation<DownloadOperation>> GetCurrentDownloadsAsync(System.String)Public Static Function GetCurrentDownloadsAsync(System.String) As IAsyncOperation( Of DownloadOperation )

    Parameters

    • group
      System.String
      System.String
      System.String
      System.String

      A string indicating a specific group of transfers.

    Returns

    • A collection of pending downloads for the specific group.

    Remarks

    On Windows Phone, this method will return the error code HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG) if the Internet capability is not declared in your app manifest. On Windows, this method will return the error code HRESULT: 0x80070005 (E_ACCESSDENIED) if the Internet capability is not declared in your app manifest. This capability is enabled by default in all Store app project templates.

  • GetCurrentDownloadsForTransferGroupAsync(Windows.Networking.BackgroundTransfer.BackgroundTransferGroup)
    GetCurrentDownloadsForTransferGroupAsync(Windows.Networking.BackgroundTransfer.BackgroundTransferGroup)
    GetCurrentDownloadsForTransferGroupAsync(Windows.Networking.BackgroundTransfer.BackgroundTransferGroup)
    GetCurrentDownloadsForTransferGroupAsync(Windows.Networking.BackgroundTransfer.BackgroundTransferGroup)

    Gets all downloads associated with the provided BackgroundTransferGroup.

    public static IAsyncOperation<DownloadOperation>> GetCurrentDownloadsForTransferGroupAsync(Windows.Networking.BackgroundTransfer.BackgroundTransferGroup)public static IAsyncOperation<DownloadOperation>> GetCurrentDownloadsForTransferGroupAsync(Windows.Networking.BackgroundTransfer.BackgroundTransferGroup)Public Static Function GetCurrentDownloadsForTransferGroupAsync(Windows.Networking.BackgroundTransfer.BackgroundTransferGroup) As IAsyncOperation( Of DownloadOperation )

    Parameters

    Returns

    • A list of downloads currently associated with the specified group.

  • RequestUnconstrainedDownloadsAsync(Windows.Foundation.Collections.IIterable{Windows.Networking.BackgroundTransfer.DownloadOperation})
    RequestUnconstrainedDownloadsAsync(Windows.Foundation.Collections.IIterable{Windows.Networking.BackgroundTransfer.DownloadOperation})
    RequestUnconstrainedDownloadsAsync(Windows.Foundation.Collections.IIterable{Windows.Networking.BackgroundTransfer.DownloadOperation})
    RequestUnconstrainedDownloadsAsync(Windows.Foundation.Collections.IIterable{Windows.Networking.BackgroundTransfer.DownloadOperation})

    Used to request an unconstrained download operation. When this method is called the user is provided with a UI prompt that they can use to indicate their consent for an unconstrained operation.An unconstrained transfer operation will run without the resource restrictions normally associated with background network operations while a device is running on battery.

    public static IAsyncOperation<UnconstrainedTransferRequestResult> RequestUnconstrainedDownloadsAsync(Windows.Foundation.Collections.IIterable{Windows.Networking.BackgroundTransfer.DownloadOperation})public static IAsyncOperation<UnconstrainedTransferRequestResult> RequestUnconstrainedDownloadsAsync(Windows.Foundation.Collections.IIterable{Windows.Networking.BackgroundTransfer.DownloadOperation})Public Static Function RequestUnconstrainedDownloadsAsync(Windows.Foundation.Collections.IIterable{Windows.Networking.BackgroundTransfer.DownloadOperation}) As IAsyncOperation( Of UnconstrainedTransferRequestResult )

    Parameters

    • operations

      The download operation to run unconstrained.

    Returns

    • Indicates if the operations will run unconstrained.

  • SetRequestHeader(System.String,System.String)
    SetRequestHeader(System.String,System.String)
    SetRequestHeader(System.String,System.String)
    SetRequestHeader(System.String,System.String)

    Used to set an HTTP request header.

    public void SetRequestHeader(System.String,System.String)public void SetRequestHeader(System.String,System.String)Public Function SetRequestHeader(System.String,System.String) As void

    Parameters

    • headerName
      System.String
      System.String
      System.String
      System.String

      The header name.

    • headerValue
      System.String
      System.String
      System.String
      System.String

      The header value.

    Remarks

    This method allows the caller to set request headers. This method can be called multiple times for the same header. The values will then be concatenated.

Device family

Windows 10 (introduced v10.0.10240.0)

API contract

Windows.Foundation.UniversalApiContract (introduced v1)

Capabilities

internetClient
internetClientServer
privateNetworkClientServer

Attributes

Windows.Foundation.Metadata.MarshalingBehaviorAttribute
Windows.Foundation.Metadata.StaticAttribute
Windows.Foundation.Metadata.ContractVersionAttribute
Windows.Foundation.Metadata.StaticAttribute
Windows.Foundation.Metadata.ThreadingAttribute
Windows.Foundation.Metadata.StaticAttribute
Windows.Foundation.Metadata.ActivatableAttribute
Windows.Foundation.Metadata.ActivatableAttribute

Details

Assembly

Windows.Networking.BackgroundTransfer.dll