Quickstart: Working with files and folders in Windows Phone 7

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

The IsolatedStorageFile class is used for saving data to a file in the app’s local folder. When you work with files, you also typically use the IsolatedStorageFileStream class to read and write content to the file.

This topic contains the following sections.

• Files and folders API overview
• Files and folders example UI
• Creating a folder and writing to a text file
• Reading a text file
• Related Topics

Files and folders API overview

The following methods are typically used when working with IsolatedStorageFile:

Files and folders example UI

The following image shows a sample app that writes text to, and reads text from the local folder.

To create this UI, in the MainPage.xaml file, replace the Grid named ContentPanel with the following XAML.

<!--ContentPanel - place additional content here-->
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0">
    <TextBox 
        Name="textBox1" 
        HorizontalAlignment="Left"
        Height="72" 
        Margin="0,22,0,0" 
        TextWrapping="Wrap" 
        Text="Enter text here." 
        VerticalAlignment="Top" Width="456"/>
    <Button 
        Name='btnWrite' 
        Content="Write"
        HorizontalAlignment="Left" 
        Margin="10,94,0,0" 
        VerticalAlignment="Top"
        Width="156" 
        Click="btnWrite_Click"/>        
    <TextBlock 
        Name="textBlock1" 
        HorizontalAlignment="Left"
        Margin="10,293,0,0" 
        TextWrapping="Wrap" Text=""
        VerticalAlignment="Top" 
        Height="61" 
        Width="436"/>     
    <Button 
        Name="btnRead" 
        Content="Read"
        HorizontalAlignment="Left" 
        Margin="10,374,0,0" 
        VerticalAlignment="Top"
        Width="156" 
        IsEnabled="False"
        Click="btnRead_Click"/>
</Grid>

Creating a folder and writing to a text file

The following code shows how to create a folder and write to a text file. A file named DataFile.txt and folder named DataFolder are created if either of them don’t already exist. An IsolatedStorageFileStream is created to write the data.

private void btnWrite_Click(object sender, RoutedEventArgs e)
{
    // Get the local folder.
    System.IO.IsolatedStorage.IsolatedStorageFile local =
        System.IO.IsolatedStorage.IsolatedStorageFile.GetUserStoreForApplication();

    // Create a new folder named DataFolder.
    if (!local.DirectoryExists("DataFolder"))
        local.CreateDirectory("DataFolder");

    // Create a new file named DataFile.txt.
    using (var isoFileStream = 
            new System.IO.IsolatedStorage.IsolatedStorageFileStream(
                "DataFolder\\DataFile.txt", 
                System.IO.FileMode.OpenOrCreate,
                    local))
    {
        // Write the data from the textbox.
        using (var isoFileWriter = new System.IO.StreamWriter(isoFileStream))
        {
            isoFileWriter.WriteLine(this.textBox1.Text);
        }
    }

    // Update UI.
    this.btnWrite.IsEnabled = false;
    this.btnRead.IsEnabled = true;
}

Instances of IsolatedStorageFile and IsolatedStorageFileStream should be disposed of after their use. The using statement does this for you automatically and its use is considered a best practice.

Reading a text file

The following code shows how to read the text data to the IsolatedStorageFileStream.

private void btnRead_Click(object sender, RoutedEventArgs e)
{
    // Obtain a virtual store for the application.
    System.IO.IsolatedStorage.IsolatedStorageFile local =
        System.IO.IsolatedStorage.IsolatedStorageFile.GetUserStoreForApplication();

    // Specify the file path and options.
    using (var isoFileStream =
            new System.IO.IsolatedStorage.IsolatedStorageFileStream
                ("DataFolder\\DataFile.txt", System.IO.FileMode.Open, local))
    {
        // Read the data.
        using (var isoFileReader = new System.IO.StreamReader(isoFileStream))
        {
            this.textBlock1.Text = isoFileReader.ReadLine();
        }
    }
    // Update UI.
    this.btnWrite.IsEnabled = true;
    this.btnRead.IsEnabled = false;
}

See Also

Other Resources

Quickstart: Working with files and folders in Windows Phone 8