private async void OnTargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs e)
{
// This scenario demonstrates how the app can go about handling the TargetFileRequested event on the UI thread, from
// which the app can manipulate the UI, show error dialogs, etc.
// Requesting a deferral allows the app to return from this event handler and complete the request at a later time.
// In this case, the deferral is required as the app intends on handling the TargetFileRequested event on the UI thread.
// Note that the deferral can be requested more than once but calling Complete on the deferral a single time will complete
// original TargetFileRequested event.
var deferral = e.Request.GetDeferral();
await dispatcher.RunAsync(CoreDispatcherPriority.Normal, async() =>
{
// This method will be called on the app's UI thread, which allows for actions like manipulating
// the UI or showing error dialogs
// Display a dialog indicating to the user that a corrective action needs to occur
var errorDialog = new Windows.UI.Popups.MessageDialog("If the app needs the user to correct a problem before the app can save the file, the app can use a message like this to tell the user about the problem and how to correct it.");
await errorDialog.ShowAsync();
// Set the targetFile property to null and complete the deferral to indicate failure once the user has closed the
// dialog. This will allow the user to take any neccessary corrective action and click the Save button once again.
e.Request.TargetFile = null;
deferral.Complete();
});
}
internal void Activate(FileSavePickerActivatedEventArgs args)
{
fileSavePickerUI = args.FileSavePickerUI;
Window.Current.Content = this;
this.OnNavigatedTo(null);
Window.Current.Activate();
}
public void Activate(FileSavePickerActivatedEventArgs args)
{
this.fileSavePickerUI = args.FileSavePickerUI;
this.fileSavePickerUI.TargetFileRequested += fileSavePickerUI_TargetFileRequested;
Window.Current.Content = this;
Window.Current.Activate();
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
// 获取 FileSavePickerUI 对象（从 App.xaml.cs 传来的）
FileSavePickerActivatedEventArgs args = (FileSavePickerActivatedEventArgs)e.Parameter;
_fileSavePickerUI = args.FileSavePickerUI;
_fileSavePickerUI.Title = "自定义文件保存选取器";
// 通过 AllowedFileTypes 获取到的允许的扩展名是在调用端的 FileSavePicker.FileTypeChoices 中配置的，实际保存扩展名可以不与其匹配
IReadOnlyList <string> allowedFileTypes = _fileSavePickerUI.AllowedFileTypes;
lblMsg.Text = "allowedFileTypes: " + string.Join(",", allowedFileTypes);
lblMsg.Text += Environment.NewLine;
lblMsg.Text += "Kind: " + args.Kind;
lblMsg.Text += Environment.NewLine;
lblMsg.Text += "SplashScreen.ImageLocation: " + args.SplashScreen.ImageLocation;
lblMsg.Text += Environment.NewLine;
lblMsg.Text += "PreviousExecutionState: " + args.PreviousExecutionState;
lblMsg.Text += Environment.NewLine;
lblMsg.Text += "CallerPackageFamilyName: " + args.CallerPackageFamilyName;
lblMsg.Text += Environment.NewLine;
lblMsg.Text += "User.NonRoamableId: " + args.User.NonRoamableId;
lblMsg.Text += Environment.NewLine;
_fileSavePickerUI.TargetFileRequested += _fileSavePickerUI_TargetFileRequested;
}
private async void OnTargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs args)
{
var deferral = args.Request.GetDeferral();
await Window.Current.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, async() =>
{
// This method will be called on the app's UI thread, which allows for actions like manipulating
// the UI or showing error dialogs
try
{
var folder = await StorageFolder.GetFolderFromPathAsync(SavePath);
var file = await folder.CreateFileAsync(sender.FileName, CreationCollisionOption.GenerateUniqueName);
args.Request.TargetFile = file;
deferral.Complete();
}
catch (ArgumentException)
{
// originates from folder access
var errorDialog = new MessageDialog(
"The save picker app you chose gave an invalid folder path. Please check again.");
await errorDialog.ShowAsync();
args.Request.TargetFile = null;
deferral.Complete();
}
catch (UnauthorizedAccessException)
{
// can originate from folder access or file creation
var errorDialog = new MessageDialog(
"You do not have permission to save a file in this folder. Please check your app permissions.");
await errorDialog.ShowAsync();
args.Request.TargetFile = null;
deferral.Complete();
}
catch (FileNotFoundException)
{
// either folder does not exist or file name is invalid
var errorDialog = new MessageDialog(
"The file name may contain invalid characters. Please check your file name again.");
await errorDialog.ShowAsync();
args.Request.TargetFile = null;
deferral.Complete();
}
catch (Exception ex)
{
var errorDialog = new MessageDialog(
$"An error has occurred: {ex.Message}");
await errorDialog.ShowAsync();
args.Request.TargetFile = null;
deferral.Complete();
}
finally
{
deferral.Complete();
}
});
}
private async void OnTargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs e)
{
// This scenario demonstrates how to handle the TargetFileRequested event on the background thread on which it was raised
// Requesting a deferral allows the app to call another asynchronous method and complete the request at a later time
var deferral = e.Request.GetDeferral();
StorageFile file;
// If the checkbox is checked then the requested file name will be ConflictingFile.txt instead of what was sent to us in sender.name.
// If background task sees that ConflictingFile is in the name of the file it sets the returned status to FileUpdateStatus.UserInputNeeded.
// This will cause a prompt for the user to open the app to fix the conflict.
if (simulateUpdateConflict)
{
file = await ApplicationData.Current.LocalFolder.CreateFileAsync("ConflictingFile.txt", CreationCollisionOption.ReplaceExisting);
}
else
{
file = await ApplicationData.Current.LocalFolder.CreateFileAsync(sender.FileName, CreationCollisionOption.ReplaceExisting);
}
CachedFileUpdater.SetUpdateInformation(file, "CachedFile", ReadActivationMode.NotNeeded, WriteActivationMode.AfterWrite, CachedFileOptions.RequireUpdateOnAccess);
e.Request.TargetFile = file;
// Complete the deferral to let the Picker know the request is finished
deferral.Complete();
}
async void _save_basket_TargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs args)
{
var deferral = args.Request.GetDeferral();
args.Request.TargetFile = await ApplicationData.Current.RoamingFolder.CreateFileAsync($"resumes\\{_save_basket.FileName}", CreationCollisionOption.GenerateUniqueName);
deferral.Complete();
}
public void Activate(FileSavePickerActivatedEventArgs args)
{
_saving = true;
_save_basket = args.FileSavePickerUI;
_save_basket.TargetFileRequested += _save_basket_TargetFileRequested;
Window.Current.Content = this;
Window.Current.Activate();
}
private async void OnTargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs e)
{
// This scenario demonstrates how to 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();
e.Request.TargetFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(sender.FileName, CreationCollisionOption.GenerateUniqueName);
// Complete the deferral to let the Picker know the request is finished
deferral.Complete();
}
private async void OnTargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs e)
{
// This scenario demonstrates how to 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);
CachedFileUpdater.SetUpdateInformation(file, "CachedFile", ReadActivationMode.NotNeeded, WriteActivationMode.AfterWrite, CachedFileOptions.RequireUpdateOnAccess);
e.Request.TargetFile = file;
// Complete the deferral to let the Picker know the request is finished
deferral.Complete();
}
/// <summary>
/// File Save Operation, create new file under Images folder and linked the new file to the selected note.
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
async void fileSavePickerUI_TargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs args)
{
if (note == null)
{
Helpers.ShowMessageAsync("Please select at least one Note to save the image.", "Save Image");
return;
}
var deferral = args.Request.GetDeferral();
args.Request.TargetFile = await DataManager.CreateFileAsync(this.fileSavePickerUI.FileName, FolderNames.Images);
note.Images.Add(string.Format("{0}/{1}", FolderNames.Images, args.Request.TargetFile.Name));
DataManager.Save();
// Complete the deferral to let the Picker know the request is finished
deferral.Complete();
}
/// <summary>
/// Used to set up the content to be displayed and connect to the containing File Open Picker
/// </summary>
/// <param name="fileSavePickerUI">The file save picker UI element.</param>
public void Initialize(FileSavePickerUI fileSavePickerUI)
{
if (fileSavePickerUI == null)
{
throw new ArgumentNullException("fileSavePickerUI");
}
// Tie into the containing File Picker object
_fileSavePickerUI = fileSavePickerUI;
_fileSavePickerUI.TargetFileRequested += HandleTargetFileRequested;
// Initialize the ViewModel
DefaultViewModel["CanGoUp"] = false;
DefaultViewModel["Contacts"] = null;
DefaultViewModel["SelectedContact"] = null;
// Load the contact info
LoadContacts();
}
/// <summary>
/// Invoked when the user presses the "Save" button in the Picker
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="args">The <see cref="TargetFileRequestedEventArgs"/> instance containing the event data.</param>
private async void HandleTargetFileRequested(FileSavePickerUI sender,
TargetFileRequestedEventArgs args)
{
var currentContact =
DefaultViewModel["SelectedContact"] as Contact;
if (currentContact == null)
{
return;
}
// Requesting a deferral allows the app to call an
// asynchronous method and complete the request.
var deferral = args.Request.GetDeferral();
// Get the target file based on the currently selected contact
args.Request.TargetFile
= await currentContact.SaveRelatedFile(sender.FileName);
// Complete the deferral to let the Picker know
// that the request processing has finished
deferral.Complete();
}
private async void _fileSavePickerUI_TargetFileRequested(FileSavePickerUI sender, TargetFileRequestedEventArgs args)
{
// 异步操作
var deferral = args.Request.GetDeferral();
try
{
// 在指定的地址新建一个没有任何内容的空白文件
StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync(sender.FileName, CreationCollisionOption.GenerateUniqueName);
// 设置 TargetFile，“自定义文件保存选取器”的调用端会收到此对象
args.Request.TargetFile = file;
}
catch (Exception ex)
{
// 输出异常信息
OutputMessage(ex.ToString());
}
finally
{
// 完成异步操作
deferral.Complete();
}
}
public FileSavePayload(FileSavePickerUI fileSavePickerUI)
{
this.fileSavePickerUI = fileSavePickerUI;
FileTypes = fileSavePickerUI.AllowedFileTypes;
this.fileSavePickerUI.TargetFileRequested += OnTargetFileRequested;
}