Creating and Writing to a new file upon selecting destination in FileSavePicker

Question

I'm having a little difficulty figuring out what the cause of this error is. I've added FilePicker capabilities in the Manifest, and it's not like I'm trying to do anything crazy; just trying to save to a sub folder within the Documents folder...

 

Error:
"An unhandled exception of type 'System.UnauthorizedAccessException' occurred in mscorlib.dll

Additional information: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))"

 

I have confirmed that my User Account is Admin and that it has Full Control over folders and files. But I'm not sure what else I can try. I'm only new to writing data to the drive in Metro apps and I have to admit, I am struggling :/

 

Any help would be appreciated.

Edit:

 

The code I am using is below:

        public void NewBTN_Click(object sender, RoutedEventArgs e)
        {

            var mbox = new MessageDialog("Would you like to save changes before creating a new Note?", "Note+ Confirmation");

            UICommand YesBTN = new UICommand("Yes", new UICommandInvokedHandler(OnYesBTN));
            UICommand NoBTN = new UICommand("No", new UICommandInvokedHandler(OnNoBTN));

            mbox.Commands.Add(YesBTN);
            mbox.Commands.Add(NoBTN);

            mbox.DefaultCommandIndex = 1;
            mbox.ShowAsync().Start();
        }

        async void OnYesBTN(object command)
        {
            this.Dispatcher.Invoke(Windows.UI.Core.CoreDispatcherPriority.Normal, (s, a) =>
                {
                    // User clicked yes. Show File picker.
                    HasPickedFile = true;

                }, this, null);

            if (HasPickedFile)
            {
                FileSavePicker savePicker = new FileSavePicker();
                savePicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
                // Dropdown of file types the user can save the file as
                savePicker.FileTypeChoices.Add("Cascading Stylesheet", new List<string>() { ".css" });
                savePicker.FileTypeChoices.Add("Hypertext Markup Language", new List<string>() { ".html" });
                savePicker.FileTypeChoices.Add("Plain Text", new List<string>() { ".txt" });
                // Default extension if the user does not select a choice explicitly from the dropdown
                savePicker.DefaultFileExtension = ".txt";
                // Default file name if the user does not type one in or select a file to replace
                savePicker.SuggestedFileName = "New Note";
                StorageFile savedItem = await savePicker.PickSaveFileAsync();

                if (null != savedItem)
                {
                    // Application now has read/write access to the saved file
                    StorageFolder sFolder = await StorageFolder.GetFolderFromPathAsync(savedItem.Path);

                    try
                    {
                        StorageFile sFile = await sFolder.GetFileAsync(savedItem.FileName);
                        IRandomAccessStream writeStream = await sFile.OpenAsync(FileAccessMode.ReadWrite);

                        IOutputStream oStream = writeStream.GetOutputStreamAt(0);
                        DataWriter dWriter = new DataWriter(oStream);
                        dWriter.WriteString(Note.Text);

                        await dWriter.StoreAsync();
                        oStream.FlushAsync().Start();

                        // Should've successfully written to the file that Windows FileSavePicker had created.
                    }
                    catch
                    {
                        var mbox = new MessageDialog("This file does not exist.", "Note+ Confirmation");

                        UICommand OkBTN = new UICommand("Ok", new UICommandInvokedHandler(OnOkBTN));

                        mbox.Commands.Add(OkBTN);

                        mbox.DefaultCommandIndex = 1;
                        mbox.ShowAsync().Start();
                    }
                }
            }
        }

        public void OnOkBTN(object command)
        {
            this.Dispatcher.Invoke(Windows.UI.Core.CoreDispatcherPriority.Normal, (s, a) =>
                {
                    // Do something here.
                }, this, null);
        }
        public void OnNoBTN(object command)
        {
            this.Dispatcher.Invoke(Windows.UI.Core.CoreDispatcherPriority.Normal, (s, a) =>
                {
                    // Don't save changes. Just create a new blank Note.
                    Note.Text = String.Empty;
                }, this, null);
        }

Answer 1

Hi J, did you add the Documents Library access in your manifest? -Jeff

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Jeff Sanders (MSFT)

Answer 2

Yep, I did Jeff! :-D But still not worky :( At first, I thought it may be a problem with how I wrote the code, but since I was following multiple tutorials on the subjects, I think that's unlikely.

 

I'm not really sure what to do next.

 

It's very strange, though. Because I just ran the FileAccess sample for C# and it saved the file to where ever I tried to save it. Then I ran the FilePicker sample, and that worked too.

 

I also created two of my own sample apps. A FileSavePicker one, and a WriteFile one. Both of which work on their own, but when combined, the file gets created by the FileSavePicker with zero-length, but the contents still never gets written to that file.

 

I'm beginning to think that maybe the order in which I am writing to the file that has been created may be wrong?

 

Jase

 

 

Answer 3

Jase,

You can send me an email from here with your project zipped up: http://blogs.msdn.com/b/jpsanders/contact.aspx

If I can recreate the issue I can debug it easier and save us both some time I hope!

-Jeff

---

Jeff Sanders (MSFT)

Answer 4

Jeff,

I am unable to upload files.

 

I'm not sure what is going on, but I cannot upload attachments to Hotmail, or any other e-mail service. I also tried uploading the zip file to Windows Live SkyDrive service to a public folder but after selecting a file to upload (using any service), nothing happens. It's as if I never clicked the 'upload' or 'attach' button to begin with. This is very strange.

 

Could it be that Windows Dev Preview is not letting apps/sites access the filesystem?

 

[*Edit*]

Finally able to attach files. Email sent!

 

Thanks

jase

Answer 5

Strange issue Jase... I have not had any problems like that using Win8 (and I have been using it for months).  For this 2nd issue, please open a thread in the General OS Forum and let's see if someone over there could have a hint for what this problem is.

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Jeff Sanders (MSFT)