IsolatedStorageFile Class

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

Represents an isolated storage area containing files and directories.

Inheritance Hierarchy

System..::.Object
System.IO.IsolatedStorage..::.IsolatedStorageFile

Namespace: System.IO.IsolatedStorage
Assembly: mscorlib (in mscorlib.dll)

Syntax

Public NotInheritable Class IsolatedStorageFile _
    Implements IDisposable
public sealed class IsolatedStorageFile : IDisposable

The IsolatedStorageFile type exposes the following members.

Properties

Name Description
AvailableFreeSpace Gets a value that represents the amount of free space available for isolated storage.
Quota Gets a value that represents the maximum amount of space available for isolated storage.

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Methods

Name Description
CopyFile(String, String) Copies an existing file to a new file.
CopyFile(String, String, Boolean) Copies an existing file to a new file, and optionally overwrites an existing file.
CreateDirectory Creates a directory in the isolated storage scope.
CreateFile Creates a file in the isolated store.
DeleteDirectory Deletes a directory in the isolated storage scope.
DeleteFile Deletes a file in the isolated store.
DirectoryExists Determines whether the specified path refers to an existing directory in the isolated store.
Dispose Releases all resources used by the IsolatedStorageFile.
Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
FileExists Determines whether the specified path refers to an existing file in the isolated store.
Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
GetCreationTime Returns the creation date and time of a specified file or directory.
GetDirectoryNames()()() Enumerates the directories in the root of an isolated store.
GetDirectoryNames(String) Enumerates directories in an isolated storage scope that match a given pattern.
GetFileNames()()() Obtains the names of files in the root of an isolated store.
GetFileNames(String) Enumerates files in isolated storage scope that match a given pattern.
GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
GetLastAccessTime Returns the date and time a specified file or directory was last accessed.
GetLastWriteTime Returns the date and time a specified file or directory was last written to.
GetType Gets the Type of the current instance. (Inherited from Object.)
GetUserStoreForApplication Obtains user-scoped isolated storage for use by an application that calls from the virtual host domain.
IncreaseQuotaTo Enables an application to explicitly request a larger quota size, in bytes.
MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
MoveDirectory Moves a specified directory and its contents to a new location.
MoveFile Moves a specified file to a new location, and optionally lets you specify a new file name.
OpenFile(String, FileMode) Opens a file in the specified mode.
OpenFile(String, FileMode, FileAccess) Opens a file in the specified mode with the specified file access.
OpenFile(String, FileMode, FileAccess, FileShare) Opens a file in the specified mode with read, write, or read/write access and the specified sharing option.
Remove Removes the isolated storage scope and all its contents.
ToString Returns a string that represents the current object. (Inherited from Object.)

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Remarks

This class abstracts the virtual file system for isolated storage. An IsolatedStorageFile object corresponds to a specific isolated storage scope, where files represented by IsolatedStorageFileStream objects exist. Applications can use isolated storage to save data in their own isolated portion of the file system, without having to specify a particular path within the file system.

The root of the virtual file system is located in a per-user, obfuscated folder on the physical file system. Each unique identifier provided by the host maps to a different root, which gives each application its own virtual file system. An application cannot navigate out of its own file system into another.

Since isolated stores are scoped to particular assemblies, most other managed code will not be able to access your code's data (highly trusted managed code and administration tools can access stores from other assemblies). Unmanaged code can access any isolated stores.

Examples

The following example shows how to use an IsolatedStorageFile object for most I/O tasks. For information on how to compile and run this example code, see Building examples that have static TextBlock controls for Windows Phone 8

Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Input
Imports System.IO
Imports System.IO.IsolatedStorage
Imports System.Collections
Imports System.Text


Class Example

    Public Shared Sub Demo(ByVal outputBlock As TextBlock)
        ' Obtain an isolated store for an application.
        Try
            Using store As IsolatedStorageFile = _
                IsolatedStorageFile.GetUserStoreForApplication()
                ' Use a StringBuilder to construct output.
                Dim sb As StringBuilder = New StringBuilder

                ' Create three directories in the root.
                store.CreateDirectory("MyApp1")
                store.CreateDirectory("MyApp2")
                store.CreateDirectory("MyApp3")

                ' Create three subdirectories under MyApp1.
                Dim subdirectory1 As String = Path.Combine("MyApp1", "SubDir1")
                Dim subdirectory2 As String = Path.Combine("MyApp1", "SubDir2")
                Dim subdirectory3 As String = Path.Combine("MyApp1", "SubDir3")
                store.CreateDirectory(subdirectory1)
                store.CreateDirectory(subdirectory2)
                store.CreateDirectory(subdirectory3)

                ' Create a file in the root.
                Dim rootFile As IsolatedStorageFileStream = _
                    store.CreateFile("InTheRoot.txt")
                rootFile.Close()


                ' Create a file in a subdirectory.
                Dim subDirFile As IsolatedStorageFileStream = _
                    store.CreateFile(Path.Combine(subdirectory1, "MyApp1A.txt"))
                subDirFile.Close()

                ' Gather file information.
                Dim directoriesInTheRoot() As String = store.GetDirectoryNames

                Dim filesInTheRoot() As String = store.GetFileNames

                Dim searchpath As String = Path.Combine(subdirectory1, "*.*")
                Dim filesInSubDirs() As String = store.GetFileNames(searchpath)

                ' Find subdirectories within the MyApp1
                ' directory using the multi character '*' wildcard.
                Dim subDirectories() As String = _
                    store.GetDirectoryNames(Path.Combine("MyApp1", "*"))

                ' List file infomration

                ' List the directories in the root.
                sb.AppendLine("Directories in root:")
                For Each dir As String In directoriesInTheRoot
                    sb.AppendLine((" - " + dir))
                Next
                sb.AppendLine()
                ' List the subdirectories under MyApp1.
                sb.AppendLine("Directories under MyApp1:")
                For Each sDir As String In subDirectories
                    sb.AppendLine((" - " + sDir))
                Next
                sb.AppendLine()
                ' List files in the root.
                sb.AppendLine("Files in the root:")
                For Each fileName As String In filesInTheRoot
                    sb.AppendLine((" - " + fileName))
                Next
                sb.AppendLine()
                ' List files in MyApp1\SubDir1.
                sb.AppendLine("Files in MyApp1\SubDir1:")
                For Each fileName As String In filesInSubDirs
                    sb.AppendLine((" - " + fileName))
                Next
                sb.AppendLine()

                ' Write to an existing file: MyApp1\SubDir1\MyApp1A.txt

                ' Determine if the file exists before writing to it.
                Dim filePath As String = Path.Combine(subdirectory1, "MyApp1A.txt")

                If store.FileExists(filePath) Then
                    Try
                        Using sw As StreamWriter = _
                            New StreamWriter(store.OpenFile(filePath, FileMode.Open, FileAccess.Write))

                            sw.WriteLine("To do list:")
                            sw.WriteLine("1. Buy supplies.")
                        End Using

                    Catch ex As IsolatedStorageException
                        sb.AppendLine(ex.Message)
                    End Try
                Else
                    sb.AppendLine((filePath + "does not exist"))
                End If

                ' Read the contents of the file: MyApp1\SubDir1\MyApp1A.txt
                Try
                    Using reader As StreamReader = _
                        New StreamReader(store.OpenFile(filePath, FileMode.Open, FileAccess.Read))
                        Dim contents As String = reader.ReadToEnd
                        sb.AppendLine(filePath + " contents:")
                        sb.AppendLine(contents)
                    End Using
                Catch ex As IsolatedStorageException
                    sb.Append(ex.Message)
                End Try


                ' Delete a file.
                Try
                    If store.FileExists(filePath) Then
                        store.DeleteFile(filePath)
                    End If
                Catch ex As IsolatedStorageException
                    sb.AppendLine(ex.Message)
                End Try

                ' Delete a specific directory.
                Dim dirDelete As String = Path.Combine("MyApp1", "SubDir3")
                Try
                    If store.DirectoryExists(dirDelete) Then
                        store.DeleteDirectory(dirDelete)
                    End If
                Catch ex As IsolatedStorageException
                    sb.AppendLine(ex.Message)
                End Try

                sb.AppendLine()
                ' remove the store
                store.Remove()

                sb.AppendLine("Store removed.")
                outputBlock.Text = sb.ToString()
            End Using
        Catch Ex As IsolatedStorageException
            ' TODO: Handle that store was unable to be accessed.
        End Try
    End Sub
End Class

' Quota status in increase examples
Class StoreQuota

    ' Assumes an event handler for the MouseLeftbuttonUp
    ' event is defined for a control named 'IncreaseQuota'
    ' In the control's XAML: MouseLeftButtonUp="IncreaseQuota_OnLeftMouseButtonUp"
    Public Sub IncreaseQuota_OnClick(ByVal sender As Object, ByVal e As MouseEventArgs)
        ' Obtain an isolated store for an application.
        Try
            Using store As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
                ' Request 5MB more space in bytes.
                Dim spaceToAdd As Int64 = 5242880
                Dim curAvail As Int64 = store.AvailableFreeSpace
                ' If available space is less than
                ' what is requested, try to increase.
                If (curAvail < spaceToAdd) Then
                    ' Request more quota space.
                    If Not store.IncreaseQuotaTo((store.Quota + spaceToAdd)) Then
                        ' The user clicked NO to the
                        ' host's prompt to approve the quota increase.
                    Else
                        ' The user clicked YES to the
                        ' host's prompt to approve the quota increase.
                    End If
                End If
            End Using
        Catch Ex As IsolatedStorageException

            ' TODO: Handle that store could not be accessed.
        End Try
    End Sub




    Public Shared Sub ShowIsoStoreStatus(ByVal inputBlock As TextBlock)
        ' Obtain an isolated store for an application.
        Try
            Using store As IsolatedStorageFile = _
              IsolatedStorageFile.GetUserStoreForApplication()
                Dim spaceUsed As String = (store.Quota - store.AvailableFreeSpace).ToString
                Dim spaceAvailable As String = store.AvailableFreeSpace.ToString
                Dim curQuota As String = store.Quota.ToString
                inputBlock.Text = String.Format("Quota: {0} bytes, Used: {1} bytes, Available: {2} bytes", _
                                         curQuota, spaceUsed, spaceAvailable)
            End Using
        Catch Ex As IsolatedStorageException
            inputBlock.Text = "Unable to access store."
        End Try
    End Sub
End Class

' This example's Example.Demo method 
' produces the following output:
' -----
' Directories in root:
' - MyApp1
' - MyApp2
' - MyApp3

' Directories under MyApp1:
' - SubDir1
' - SubDir2
' - SubDir3

' Files in the root:
' - InTheRoot.txt

' Files in MyApp1\SubDir1:
' - MyApp1A.txt

' MyApp1\SubDir1\MyApp1A.txt contents:
' To do list:
' 1. Buy supplies.

' Store removed.
' -----
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.IO;
using System.IO.IsolatedStorage;
using System.Collections;
using System.Text;

class Example
{
    public static void Demo(TextBlock outputBlock)
    {
        // Obtain an isolated store for an application.
        try
        {
            using (var store = IsolatedStorageFile.GetUserStoreForApplication())
            {
                // Use a StringBuilder to construct output.
                StringBuilder sb = new StringBuilder();

                // Create three directories in the root.
                store.CreateDirectory("MyApp1");
                store.CreateDirectory("MyApp2");
                store.CreateDirectory("MyApp3");

                // Create three subdirectories under MyApp1.
                string subdirectory1 = Path.Combine("MyApp1", "SubDir1");
                string subdirectory2 = Path.Combine("MyApp1", "SubDir2");
                string subdirectory3 = Path.Combine("MyApp1", "SubDir3");
                store.CreateDirectory(subdirectory1);
                store.CreateDirectory(subdirectory2);
                store.CreateDirectory(subdirectory3);

                // Create a file in the root.
                IsolatedStorageFileStream rootFile = store.CreateFile("InTheRoot.txt");
                rootFile.Close();

                // Create a file in a subdirectory.
                IsolatedStorageFileStream subDirFile =
                    store.CreateFile(Path.Combine(subdirectory1, "MyApp1A.txt"));
                subDirFile.Close();

                // Gather file information
                string[] directoriesInTheRoot = store.GetDirectoryNames();

                string[] filesInTheRoot = store.GetFileNames();

                string searchpath = Path.Combine(subdirectory1, "*.*");
                string[] filesInSubDirs = store.GetFileNames(searchpath);

                // Find subdirectories within the MyApp1
                // directory using the multi character '*' wildcard.
                string[] subDirectories =
                    store.GetDirectoryNames(Path.Combine("MyApp1", "*"));

                // List file information

                // List the directories in the root.
                sb.AppendLine("Directories in root:");
                foreach (string dir in directoriesInTheRoot)
                {
                    sb.AppendLine(" - " + dir);
                }
                sb.AppendLine();

                // List the subdirectories under MyApp1.
                sb.AppendLine("Directories under MyApp1:");
                foreach (string sDir in subDirectories)
                {
                    sb.AppendLine(" - " + sDir);
                }
                sb.AppendLine();

                // List files in the root.
                sb.AppendLine("Files in the root:");
                foreach (string fileName in filesInTheRoot)
                {
                    sb.AppendLine(" - " + fileName);
                }
                sb.AppendLine();

                // List files in MyApp1\SubDir1.
                sb.AppendLine(@"Files in MyApp1\SubDir1:");
                foreach (string fileName in filesInSubDirs)
                {
                    sb.AppendLine(" - " + fileName);
                }
                sb.AppendLine();

                // Write to an existing file: MyApp1\SubDir1\MyApp1A.txt

                // Determine if the file exists before writing to it.
                string filePath = Path.Combine(subdirectory1, "MyApp1A.txt");

                if (store.FileExists(filePath))
                {
                    try
                    {
                        using (StreamWriter sw =
                            new StreamWriter(store.OpenFile(filePath,
                                FileMode.Open, FileAccess.Write)))
                        {
                            sw.WriteLine("To do list:");
                            sw.WriteLine("1. Buy supplies.");
                        }
                    }
                    catch (IsolatedStorageException ex)
                    {

                        sb.AppendLine(ex.Message);
                    }
                }

                // Read the contents of the file: MyApp1\SubDir1\MyApp1A.txt
                try
                {
                    using (StreamReader reader =
                        new StreamReader(store.OpenFile(filePath,
                            FileMode.Open, FileAccess.Read)))
                    {
                        string contents = reader.ReadToEnd();
                        sb.AppendLine(filePath + " contents:");
                        sb.AppendLine(contents);
                    }
                }
                catch (IsolatedStorageException ex)
                {

                    sb.AppendLine(ex.Message);
                }

                // Delete a file.
                try
                {
                    if (store.FileExists(filePath))
                    {
                        store.DeleteFile(filePath);
                    }
                }
                catch (IsolatedStorageException ex)
                {
                    sb.AppendLine(ex.Message);
                }

                // Delete a specific directory.
                string dirDelete = Path.Combine("MyApp1", "SubDir3");
                try
                {
                    if (store.DirectoryExists(dirDelete))
                    {
                        store.DeleteDirectory(dirDelete);
                    }
                }
                catch (IsolatedStorageException ex)
                {
                    sb.AppendLine(ex.Message);
                }


                sb.AppendLine();


                // remove the store
                store.Remove();

                sb.AppendLine("Store removed.");

                outputBlock.Text = sb.ToString();
            }
        }
        catch (IsolatedStorageException)
        {
            // TODO: Handle that store was unable to be accessed.

        }
    }
}

// Quota status and increase quota examples
class StoreQuota
{

    // Assumes an event handler for the MouseLeftbuttonUp
    // event is defined for a control named 'IncreaseQuota'
    // In the control's XAML: MouseLeftButtonUp="IncreaseQuota_OnLeftMouseButtonUp"

    // User first selects UI to increase the quota.
    public void IncreaseQuota_OnClick(object sender, MouseEventArgs e)
    {

        // Obtain an isolated store for an application.
        try
        {
            using (var store = IsolatedStorageFile.GetUserStoreForApplication())
            {
                // Request 5MB more space in bytes.
                Int64 spaceToAdd = 5242880;
                Int64 curAvail = store.AvailableFreeSpace;

                // If available space is less than
                // what is requested, try to increase.
                if (curAvail < spaceToAdd)
                {

                    // Request more quota space.
                    if (!store.IncreaseQuotaTo(store.Quota + spaceToAdd))
                    {
                        // The user clicked NO to the
                        // host's prompt to approve the quota increase.
                    }
                    else
                    {
                        // The user clicked YES to the
                        // host's prompt to approve the quota increase.
                    }
                }
            }
        }

        catch (IsolatedStorageException)
        {
            // TODO: Handle that store could not be accessed.

        }
    }

    public static void ShowIsoStoreStatus(TextBlock inputBlock)
    {

        // Obtain an isolated store for an application.
        try
        {
            using (var store = IsolatedStorageFile.GetUserStoreForApplication())
            {
                string spaceUsed = (store.Quota - store.AvailableFreeSpace).ToString();
                string spaceAvailable = store.AvailableFreeSpace.ToString();
                string curQuota = store.Quota.ToString();
                inputBlock.Text =
                    String.Format("Quota: {0} bytes, Used: {1} bytes, Available: {2} bytes",
                            curQuota, spaceUsed, spaceAvailable);
            }
        }

        catch (IsolatedStorageException)
        {
            inputBlock.Text = "Unable to access store.";

        }
    }

}
// This example's Example.Demo method
// produces the following output:
// -----
// Directories in root:
// - MyApp1
// - MyApp2
// - MyApp3

// Directories under MyApp1:
// - SubDir1
// - SubDir2
// - SubDir3

// Files in the root:
// - InTheRoot.txt

// Files in MyApp1\SubDir1:
// - MyApp1A.txt

// MyApp1\SubDir1\MyApp1A.txt contents:
// To do list:
// 1. Buy supplies.

// Store removed.
// -----

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

System.IO.IsolatedStorage Namespace

Other Resources

How to use the Isolated Storage Explorer tool for Windows Phone 8

How to store files and folders for Windows Phone