Saving to Windows Phone Documents Folder

Question

Greetings,
I tried to look through the forum but could not find anything on saving to the Windows Phone Documents folder. From what I researched online on the Windows Phone 8 it was not possible to do this as Microsoft had blocked the ability to do this due to security
reasons. But on the 8.1 release they allowed this area to be accessed by third party apps. Is this correct?
If so how do I go abouts saving to the documents folder. Basically my app is really simple I just input a couple of words into different text boxes and that should save to a text file. How do I go abouts doing this.
I tried doing this
StorageFolder local = KnownFolders.DocumentsLibrary;
However, when I run it the program stops at this spot:
#if DEBUG && !DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION
            UnhandledException += (sender, e) =>
                if
(global::System.Diagnostics.Debugger.IsAttached) global::System.Diagnostics.Debugger.Break();
#endif
What am I doing wrong. Thank you in advanced!!

Answer 1

I apologize for that I looked at it quickly on my phone. Ok so I managed to get it to save to a file. The problem is now is I want to be able to append to that same file. Is that possible?
Here is what I have so far:
using SDKTemplate;
using System;
using System.Collections.Generic;
using Windows.ApplicationModel.Activation;
using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.Storage.Provider;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;
namespace FilePicker
    /// <summary>
    /// Implement IFileSavePickerContinuable interface, in order that Continuation Manager can automatically
    /// trigger the method to process returned file.
    /// </summary>
    public sealed partial class Scenario4 : Page, IFileSavePickerContinuable
        MainPage rootPage = MainPage.Current;
        public Scenario4()
            this.InitializeComponent();
            SaveFileButton.Click += new RoutedEventHandler(SaveFileButton_Click);
        private void SaveFileButton_Click(object sender, RoutedEventArgs e)
            // Clear previous returned file name, if it exists, between iterations of this scenario
            OutputTextBlock.Text = "";
            FileSavePicker savePicker = new FileSavePicker();
            savePicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
            // Dropdown of file types the user can save the file as
            savePicker.FileTypeChoices.Add("Plain Text", new List<string>() { ".csv" });
            // Default file name if the user does not type one in or select a file to replace
            savePicker.SuggestedFileName = "New Document";
            savePicker.PickSaveFileAndContinue();
        /// <summary>
        /// Handle the returned file from file picker
        /// This method is triggered by ContinuationManager based on ActivationKind
        /// </summary>
        /// <param name="args">File save picker continuation activation argment. It cantains the file user selected with file save picker </param>
        public async void ContinueFileSavePicker(FileSavePickerContinuationEventArgs args)
            string complete = "";
            string office = "";
            string revenue = "";
            string nps = "";
            string answer;
            answer = NotesTxt.Text;
            StorageFile file = args.File;
            if (file != null)
                // Prevent updates to the remote version of the file until we finish making changes and call CompleteUpdatesAsync.
                CachedFileManager.DeferUpdates(file);
                // write to file
                await FileIO.WriteTextAsync(file, answer);
                // Let Windows know that we're finished changing the file so the other app can update the remote version of the file.
                // Completing updates may require Windows to ask for user input.
                FileUpdateStatus status = await CachedFileManager.CompleteUpdatesAsync(file);
                if (status == FileUpdateStatus.Complete)
                    OutputTextBlock.Text = "File " + file.Name + " was saved.";
                else
                    OutputTextBlock.Text = "File " + file.Name + " couldn't be saved.";
            else
                OutputTextBlock.Text = "Operation cancelled.";
        private void SaveFileButton_Click_1(object sender, RoutedEventArgs e)