從Toast Notification打開文件

Question

在我的UWP應用中，我正在下載文件並將其存儲在用戶使用FolderPicker選擇的位置中。 下載完成后，我將顯示ToastNotification。 我正在使用這兩個名稱空間，如文檔所示。

using Microsoft.QueryStringDotNET; // for receciving arguments
using Microsoft.Toolkit.Uwp.Notifications;

我發送的吐司有兩個按鈕，1）打開文件2）關閉。 我想在用戶點擊第一個按鈕時打開下載的文件。

但是據我了解，敬酒只能將字符串參數發送給應用程序（如果出錯，請更正我）。 並且為了打開文件，需要StorageFile對象（ StorageFile路徑不做）。

那么，有什么方法可以從吐司中實際打開下載的文件（使用前台激活還是后台激活）？

下載文件的代碼：

private async void DownloadButton_Click(object sender, RoutedEventArgs e)
{   
    StorageFolder selectedFolder;   
    try
    {
        selectedFolder = await ChooseFolderAsync();
    }
    catch
    {
        Toast.ShowToast("Something went wrong", ToastRow);
        return;
    }

    Uri downloadLink = new Uri("ValidUri");    

    StorageFile destinationFile = await selectedFolder.CreateFileAsync(selectedAsset.name, CreationCollisionOption.GenerateUniqueName);

    BackgroundDownloader downloader = new BackgroundDownloader();
    downloader.SuccessToastNotification = handler.MakeToastWithButtons("Downloaded", selectedAsset.name, "Open", "Dismiss");
   // downloader.SuccessToastNotification = handler.MakeToast("Downloaded", nameOfFile, string.Empty, 2);
    DownloadOperation download = downloader.CreateDownload(downloadLink, destinationFile);
    download.Priority = BackgroundTransferPriority.High;
    download.CostPolicy = BackgroundTransferCostPolicy.Always;    

    var toast = handler.MakeToast("Downloading...", selectedAsset.name, selectedAsset.contentSize, 12);
    toast.Group = "downloadStartedTag";
    ToastNotificationManager.CreateToastNotifier().Show(toast);

    Progress<DownloadOperation> progressCallback = new Progress<DownloadOperation>(handler.DownloadProgress);

    try
    {
        await download.StartAsync().AsTask(cts.Token, progressCallback);       
    }
    catch (Exception ex)
    {
        var errorCode = BackgroundTransferError.GetStatus(ex.HResult);
        toast = handler.MakeToast("Download failed", selectedAsset.name, TextFormatter.CamelToHumanCase(errorCode.ToString()), 12);
        toast.Group = "downloadFailedTag";
        ToastNotificationManager.CreateToastNotifier().Show(toast);

        return;
    }
    finally
    {
        ToastNotificationManager.History.Remove("downloadStartedTag");
    }   
}

創建吐司的方法：

public ToastNotification MakeToastWithButtons(string heading, string line1, string button1, string button2)
{
    ToastVisual visual = new ToastVisual()
    {
        BindingGeneric = new ToastBindingGeneric()
        {
            Children =
            {
                new AdaptiveText() {Text = heading},
                new AdaptiveText() {Text = line1},
            }
        }
    };

    ToastActionsCustom actions = new ToastActionsCustom()
    {
        Buttons =
        {
            new ToastButton("Open", new QueryString()
            {
                { "action", "open" }
                //maybe file path can be given here in some argument

            }.ToString())
            {
                ActivationType = ToastActivationType.Foreground
            },

            new ToastButton("Dismiss", new QueryString()
            {
                { "action", "dismiss" }
                //more details about the file can be given here

            }.ToString())
            {
                ActivationType = ToastActivationType.Background
            }                        
        }

    };

    ToastContent toastContent = new ToastContent()
    {
        Visual = visual,
        Actions = actions,

        // Arguments when the user taps body of toast
        Launch = new QueryString()
        {
            { "action", "nothing" }
        }.ToString()
    };

    // And create the toast notification
    var toast = new ToastNotification(toastContent.GetXml());
    toast.ExpirationTime = DateTime.Now.AddDays(2);
    toast.Group = "DownloadCompleteGroup";

    return toast;
}

Answer 1

一種方法是將由后台下載創建的destinationFile存儲在FutureAccessList ，這將為您提供一個token您可以將其添加到Toast的有效載荷數據中：

// using Windows.Storage.AccessCache;
string token = StorageApplicationPermissions.FutureAccessList.Add(destinationFile);
// add the token to your toast payload

然后，當用戶單擊烤面包時，您可以兌換token以將文件取回：

var file = await StorageApplicationPermissions.FutureAccessList.GetFileAsync(token);

現在，您可以使用該文件了。 請注意，令牌是“永遠”的好東西-只要文件存在於磁盤上，令牌將在您的應用重啟甚至重啟后起作用。

處理完文件后（包括下載失敗或用戶取消等），您應該從FutureAccessList刪除令牌， FutureAccessList使列表不填滿：

StorageApplicationPermissions.FutureAccessList.Remove(token);

這意味着您可能還希望將令牌也保留在應用程序的設置中，以防萬一用戶忽略了吐司。