How to: Store Files and Folders for Windows Phone

In Visual Studio 2010 Express for Windows Phone, create a new project by selecting the File | New Project menu command.

The New Project window is displayed. Expand the Visual C# templates, and then select the Silverlight for Windows Phone templates.

Select the Windows Phone Application template. Fill in the Name with a name of your choice.

Click OK. The New Windows Phone Application window is displayed.

In the Target Windows Phone Version menu, ensure that Windows Phone 7.1 is selected.

Click OK. A new project is created, and MainPage.xaml is opened in the Visual Studio designer window.

From the designer view on MainPage.xaml, select page title and change the title text to files/folders in the Text property or directly in the XAML. You can also rename the application title if you want to.

Add the following resources in the code-behind page to include the following namespaces. For example, if you are using the main page with the default naming convention, you would update MainPage.xaml.cs.

using System.IO;
using System.IO.IsolatedStorage;

On MainPage.xaml, drag a TextBox and a Button control from the Toolbox and place the controls near the top of the page. Scale and position the controls by using the following illustration as a reference.

Rename the TextBox to txtWrite and rename the Button to btnWrite.

For the TextBox, remove the text TextBox from the control Text property, and change the button text to Write in the content property.

On MainPage.xaml, drag a TextBlock and a Button control from the Toolbox and place the controls near the bottom of the page. Scale and position the controls by using the illustration below as a reference.

Rename the TextBlock to txtRead and rename the Button to btnRead. For the TextBlock, remove the text TextBlock from the control Text property, and change the button text to Read in the content property.

Double-click the btnWrite button to add an event handler for the click event. The MainPage.xaml.cs file opens.

The objective is to add code to obtain a virtual store where you can create files and folders for your application. To highlight a simple file and folder hierarchy, you create a folder and then create a text file inside that folder. For the btnWrite_Click event handler, add the following code.

private void btnWrite_Click(object sender, RoutedEventArgs e)
{
    // Obtain the virtual store for the application.
    IsolatedStorageFile myStore = IsolatedStorageFile.GetUserStoreForApplication();

    // Create a new folder and call it "MyFolder".
    myStore.CreateDirectory("MyFolder");

    // Specify the file path and options.
    using (var isoFileStream = new IsolatedStorageFileStream("MyFolder\\myFile.txt", FileMode.OpenOrCreate, myStore))
    {
        //Write the data
        using (var isoFileWriter = new StreamWriter(isoFileStream))
        {
            isoFileWriter.WriteLine(txtWrite.Text);
        }
    }
}

Double-click the btnRead button to add an event handler for the click event. The MainPage.xaml.cs file opens.

For the btnRead_Click event handler, add the following code.

// This code opens and reads the contents of myFile.txt.
private void btnRead_Click(object sender, RoutedEventArgs e)
{
    // Obtain a virtual store for the application.
    IsolatedStorageFile myStore = IsolatedStorageFile.GetUserStoreForApplication();

    try
    {
        // Specify the file path and options.
        using (var isoFileStream = new IsolatedStorageFileStream("MyFolder\\myFile.txt", FileMode.Open, myStore))
        {
            // Read the data.
            using (var isoFileReader = new StreamReader(isoFileStream))
            {
                txtRead.Text = isoFileReader.ReadLine();
            }
        }

    }
    catch
    {
        // Handle the case when the user attempts to click the Read button first.
        txtRead.Text = "Need to create directory and the file first.";
    }
}

Run the application by selecting the Debug menu and then click Start Debugging. This opens the emulator window and launches the application.