CachedFileUpdater 類別

定義

命名空間:

Windows.Storage.Provider

管理檔案，讓參與快取檔案更新程式合約的應用程式即時更新這些檔案。

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)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
public static class CachedFileUpdater

Public Class CachedFileUpdater

繼承

Object Platform::Object IInspectable CachedFileUpdater

屬性

ContractVersionAttribute MarshalingBehaviorAttribute

Windows 需求

裝置系列	Windows 10 (已於 10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox 引進)
API contract	Windows.Foundation.UniversalApiContract (已於 v1.0 引進)

範例

檔案選擇器合約範例示範如何在其 TargetFileRequested事件處理常式中設定檔案的更新資訊。

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;
    deferral.Complete();
}

備註

以靜態方式存取這個類別中的方法。

方法

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

設定本機檔案的更新原則。

另請參閱

• 檔案選擇器合約範例