IsolatedStorageFile Class

July 28, 2014

Represents an isolated storage area containing files and directories.

System.Object
  System.IO.IsolatedStorage.IsolatedStorageFile

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

public sealed class IsolatedStorageFile : IDisposable

The IsolatedStorageFile type exposes the following members.

  NameDescription
Public propertyAvailableFreeSpaceGets a value that represents the amount of free space available for isolated storage.
Public propertyQuotaGets a value that represents the maximum amount of space available for isolated storage.
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  NameDescription
Public methodCopyFile(String, String)Copies an existing file to a new file.
Public methodCopyFile(String, String, Boolean)Copies an existing file to a new file, and optionally overwrites an existing file.
Public methodCreateDirectoryCreates a directory in the isolated storage scope.
Public methodCreateFileCreates a file in the isolated store.
Public methodDeleteDirectoryDeletes a directory in the isolated storage scope.
Public methodDeleteFileDeletes a file in the isolated store.
Public methodDirectoryExistsDetermines whether the specified path refers to an existing directory in the isolated store.
Public methodDisposeReleases all resources used by the IsolatedStorageFile.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Public methodFileExistsDetermines whether the specified path refers to an existing file in the isolated store.
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetCreationTimeReturns the creation date and time of a specified file or directory.
Public methodGetDirectoryNames()Enumerates the directories in the root of an isolated store.
Public methodGetDirectoryNames(String)Enumerates directories in an isolated storage scope that match a given pattern.
Public methodGetFileNames()Obtains the names of files in the root of an isolated store.
Public methodGetFileNames(String)Enumerates files in isolated storage scope that match a given pattern.
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetLastAccessTimeReturns the date and time a specified file or directory was last accessed.
Public methodGetLastWriteTimeReturns the date and time a specified file or directory was last written to.
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodStatic memberGetUserStoreForApplicationObtains user-scoped isolated storage for use by an application that calls from the virtual host domain.
Public methodIncreaseQuotaToEnables an application to explicitly request a larger quota size, in bytes.
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodMoveDirectoryMoves a specified directory and its contents to a new location.
Public methodMoveFileMoves a specified file to a new location, and optionally lets you specify a new file name.
Public methodOpenFile(String, FileMode)Opens a file in the specified mode.
Public methodOpenFile(String, FileMode, FileAccess)Opens a file in the specified mode with the specified file access.
Public methodOpenFile(String, FileMode, FileAccess, FileShare)Opens a file in the specified mode with read, write, or read/write access and the specified sharing option.
Public methodRemoveRemoves the isolated storage scope and all its contents.
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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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.

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


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.
// -----



Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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

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