Share via

CachedFileUpdater Class


Manages files so that they can be updated in real-time by an app that participates in the Cached File Updater contract.

public ref class CachedFileUpdater abstract sealed
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
class CachedFileUpdater final
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
public static class CachedFileUpdater
Public Class CachedFileUpdater
Object Platform::Object IInspectable CachedFileUpdater

Windows requirements

Device family
Windows 10 (introduced in 10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced in v1.0)


The File picker contracts sample demonstrates how to set update information for a file in its TargetFileRequested event handler.

private async void OnTargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs e)
    // Handle the TargetFileRequested event on the background thread on which it was raised

    // Requesting a deferral allows the app to call another asynchronous method and complete the request at a later time
    var deferral = e.Request.GetDeferral();

    StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync(sender.FileName, CreationCollisionOption.ReplaceExisting);

    // Set update info for the file
    CachedFileUpdater.SetUpdateInformation(file, "CachedFile", ReadActivationMode.NotNeeded, WriteActivationMode.AfterWrite, CachedFileOptions.RequireUpdateOnAccess);

    // Assign the resulting file to the targetFile property and complete the deferral to indicate success  
    e.Request.TargetFile = file;


Access methods in this class statically.


SetUpdateInformation(IStorageFile, String, ReadActivationMode, WriteActivationMode, CachedFileOptions)

Configures update policies for a local file.

Applies to

See also