xaml - 使用共享合同在 Windows 8 Metro 应用程序中共享文件时出现“在意外时间调用方法”的异常？

Question

我正在尝试在我的应用程序中使用共享合同共享文件：-

public async void SendingEmail(UtilityClass objselecteditem)
{
    try
    {
        StorageFolder tempFolder = Windows.Storage.ApplicationData.Current.LocalFolder;
        StorageFile sampleFile = await 
        tempFolder.CreateFileAsync("StundentDetails.html",   
            CreationCollisionOption.ReplaceExisting);
        await Windows.Storage.FileIO.WriteTextAsync(sampleFile, htmlBuilder.ToString());
        await RegisterForShare();                        
    }
    catch (Exception ex)
    {    
    }
}

我在上面的方法中调用了这个 RegisterForShare() ：-

private async Task RegisterForShare()
{
    DataTransferManager dataTransferManager = DataTransferManager.GetForCurrentView();       
    dataTransferManager.DataRequested += new TypedEventHandler<DataTransferManager, DataRequestedEventArgs>(this.ShareStorageItemsHandler);            
    DataTransferManager.ShowShareUI();

}

private async void ShareStorageItemsHandler(DataTransferManager sender, DataRequestedEventArgs e)          
{
    DataRequest request = e.Request;
    request.Data.Properties.Title = "Student Confirmation Email";
    request.Data.Properties.Description = "Student Details";



    // Because we are making async calls in the DataRequested event handler,
    // we need to get the deferral first.
    DataRequestDeferral deferral =  request.GetDeferral();

    // Make sure we always call Complete on the deferral.
    try
    {
        StorageFolder tempFolder = Windows.Storage.ApplicationData.Current.LocalFolder;
        StorageFile EmailFile = await tempFolder.GetFileAsync("StundentDetails.html");      
        List<IStorageItem> storageItems = new List<IStorageItem>();
        storageItems.Add(EmailFile);
        request.Data.SetStorageItems(storageItems);


    }
    finally
    {
        deferral.Complete();
    }
}

第一次正确执行，共享合同正在为我打开共享文件，但如果我试图再次共享它（第二次共享文件）它会抛出一个异常，说“在一个意外的时间调用了一个方法“，如果我做错了，请告诉我，请纠正我。

提前致谢。

Answer 1

尝试替换此行：

dataTransferManager.DataRequested += new TypedEventHandler<DataTransferManager, DataRequestedEventArgs>(this.ShareStorageItemsHandler); 

和

dataTransferManager.DataRequested -= ShareStorageItemsHandler;
dataTransferManager.DataRequested += ShareStorageItemsHandler;