IsolatedStorageFileStream Class
Exposes a file within isolated storage.
For a list of all members of this type, see IsolatedStorageFileStream Members.
System.Object
System.MarshalByRefObject
System.IO.Stream
System.IO.FileStream
System.IO.IsolatedStorage.IsolatedStorageFileStream
[Visual Basic] Public Class IsolatedStorageFileStream Inherits FileStream [C#] public class IsolatedStorageFileStream : FileStream [C++] public __gc class IsolatedStorageFileStream : public FileStream [JScript] public class IsolatedStorageFileStream extends FileStream
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.
Remarks
Use this class to read, write and create files in isolated storage.
Since this class extends FileStream, you can use an instance of IsolatedStorageFileStream in most situations where a FileStream might otherwise be used, such as to construct a StreamReader or StreamWriter.
Example
[Visual Basic, C#, C++] The following console application demonstrates how you can use IsolatedStorageFile and IsolatedStorageFileStream to write data to an Isolated Storage file. The user is requested to log in. If the user is a new user, a News URL and a Sports URL are recorded as personal preferences in Isolated Storage. If the user is a returning user, the user's current preferences are displayed. The code examples used throughout this namespace are presented in the context of this sample application.
[Visual Basic, C#, C++] You can use the Isolated Storage Tool (Storeadm.exe) utility to list and remove the Isolated Storage files that are created with this console application.
[Visual Basic] 'This sample demonstrates methods of classes found in the System.IO IsolatedStorage namespace. Imports System Imports System.IO Imports System.IO.IsolatedStorage Imports System.Security.Policy Imports Microsoft.VisualBasic Namespace ISOCS _ Class ConsoleApp <STAThread()> Overloads Shared _ Sub Main(ByVal args() As String) ' Prompt the user for their username. Console.WriteLine("Enter your login ID:") ' Does no error checking. Dim lp As New LoginPrefs(Console.ReadLine()) If lp.NewPrefs Then Console.WriteLine("Please set preferences for a new user.") GatherInfoFromUser(lp) ' Write the new preferences to storage. Dim percentUsed As Double = lp.SetPrefsForUser() Console.WriteLine(("Your preferences have been written. Current space used is " & percentUsed.ToString() & " %")) Else Console.WriteLine("Welcome back.") Console.WriteLine("Your preferences have expired, please reset them.") GatherInfoFromUser(lp) lp.SetNewPrefsForUser() Console.WriteLine("Your news site has been set to {0}" & ControlChars.Cr & " and your sports site has been set to {1}.", lp.NewsUrl, lp.SportsUrl) End If lp.GetIsoStoreInfo() Console.WriteLine("Enter 'd' to delete the IsolatedStorage files and exit, or press any other key to exit without deleting files.") Dim consoleInput As String = Console.ReadLine() If consoleInput.ToLower() = "d" Then lp.DeleteFiles() lp.DeleteDirectories() End If End Sub 'Main Shared Sub GatherInfoFromUser(ByVal lp As LoginPrefs) Console.WriteLine("Please enter the URL of your news site.") lp.NewsUrl = Console.ReadLine() Console.WriteLine("Please enter the URL of your sports site.") lp.SportsUrl = Console.ReadLine() End Sub 'GatherInfoFromUser End Class 'ConsoleApp _ Public Class LoginPrefs Public Sub New(ByVal myUserName As String) userName = myUserName myNewPrefs = GetPrefsForUser() End Sub 'New Private userName As String Private myNewsUrl As String Public Property NewsUrl() As String Get Return myNewsUrl End Get Set(ByVal Value As String) myNewsUrl = value End Set End Property Private mySportsUrl As String Public Property SportsUrl() As String Get Return mySportsUrl End Get Set(ByVal Value As String) mySportsUrl = value End Set End Property Private myNewPrefs As Boolean Public ReadOnly Property NewPrefs() As Boolean Get Return myNewPrefs End Get End Property Private Function GetPrefsForUser() As Boolean Try ' Retrieve an IsolatedStorageFile for the current Domain and Assembly. Dim isoFile As IsolatedStorageFile = _ IsolatedStorageFile.GetStore(IsolatedStorageScope.User _ Or IsolatedStorageScope.Assembly _ Or IsolatedStorageScope.Domain, Nothing, Nothing) Dim isoStream As New IsolatedStorageFileStream(Me.userName, FileMode.Open, _ FileAccess.Read, FileShare.Read) ' farThe code executes to this point only if a file corresponding to the username exists. ' Though you can perform operations on the stream, you cannot get a handle to the file. Try Dim aFileHandle As IntPtr = isoStream.Handle Console.WriteLine(("A pointer to a file handle has been obtained. " & aFileHandle.ToString() & " " & aFileHandle.GetHashCode())) Catch ex As Exception ' Handle the exception. Console.WriteLine("Expected exception") Console.WriteLine(ex.ToString()) End Try Dim reader As New StreamReader(isoStream) ' Read the data. Me.NewsUrl = reader.ReadLine() Me.SportsUrl = reader.ReadLine() reader.Close() isoFile.Close() Return False Catch ex As System.IO.FileNotFoundException ' Expected exception if a file cannot be found. This indicates that we have a new user. Return True End Try End Function 'GetPrefsForUser Public Function GetIsoStoreInfo() As Boolean Try 'Get a User store with type evidence for the current Domain and the Assembly. Dim isoFile As IsolatedStorageFile = _ IsolatedStorageFile.GetStore(IsolatedStorageScope.User Or _ IsolatedStorageScope.Assembly Or IsolatedStorageScope.Domain, _ GetType(System.Security.Policy.Url), GetType(System.Security.Policy.Url)) Dim dirNames As [String]() = isoFile.GetDirectoryNames("*") Dim fileNames As [String]() = isoFile.GetFileNames("*") Dim name As String ' List directories currently in this Isolated Storage. If dirNames.Length > 0 Then For Each name In dirNames Console.WriteLine("Directory Name: " & name) Next name End If ' List the files currently in this Isolated Storage. ' The list represents all users who have personal preferences stored for this application. If fileNames.Length > 0 Then For Each name In fileNames Console.WriteLine("File Name: " & name) Next name End If isoFile.Close() Return True Catch ex As Exception Console.WriteLine(ex.ToString()) End Try End Function 'GetIsoStoreInfo Public Function SetPrefsForUser() As Double Try Dim isoFile As IsolatedStorageFile isoFile = IsolatedStorageFile.GetUserStoreForDomain() ' Open or create a writable file. Dim isoStream As New IsolatedStorageFileStream(Me.userName, FileMode.OpenOrCreate, _ FileAccess.Write, isoFile) Dim writer As New StreamWriter(isoStream) writer.WriteLine(Me.NewsUrl) writer.WriteLine(Me.SportsUrl) ' Calculate the amount of space used to record the user's preferences. Dim d As Double = Convert.ToDouble(isoFile.CurrentSize) / Convert.ToDouble(isoFile.MaximumSize) Console.WriteLine(("CurrentSize = " & isoFile.CurrentSize.ToString())) Console.WriteLine(("MaximumSize = " & isoFile.MaximumSize.ToString())) ' StreamWriter.Close implicitly closes isoStream. writer.Close() isoFile.Dispose() isoFile.Close() Return d Catch ex As Exception Console.WriteLine(ex.ToString()) End Try End Function 'SetPrefsForUser 'ToDo: Handle the exception. Public Sub DeleteFiles() Try Dim isoFile As IsolatedStorageFile = IsolatedStorageFile.GetStore(IsolatedStorageScope.User Or IsolatedStorageScope.Assembly Or IsolatedStorageScope.Domain, GetType(System.Security.Policy.Url), GetType(System.Security.Policy.Url)) Dim name As String Dim dirNames As [String]() = isoFile.GetDirectoryNames("*") Dim fileNames As [String]() = isoFile.GetFileNames("*") ' List the files currently in this Isolated Storage. ' The list represents all users who have personal ' preferences stored for this application. If fileNames.Length > 0 Then For Each name In fileNames ' Delete the files. isoFile.DeleteFile(name) Next name 'Confirm no files are left. fileNames = isoFile.GetFileNames("*") End If Catch ex As Exception Console.WriteLine(ex.ToString()) End Try End Sub 'DeleteFiles ' This method deletes directories in the specified Isolated Storage, after first ' deleting the files they contain. In this example, the Archive directory is deleted. ' There should be no other directories in this Isolated Storage. Public Sub DeleteDirectories() Try Dim isoFile As IsolatedStorageFile = IsolatedStorageFile.GetStore(IsolatedStorageScope.User _ Or IsolatedStorageScope.Assembly Or IsolatedStorageScope.Domain, _ GetType(System.Security.Policy.Url), GetType(System.Security.Policy.Url)) Dim name As String Dim dirNames As [String]() = isoFile.GetDirectoryNames("*") Dim fileNames As [String]() = isoFile.GetFileNames("Archive\*") ' Delete all the files currently in the Archive directory. If fileNames.Length > 0 Then For Each name In fileNames isoFile.DeleteFile(("Archive\" & name)) Next name 'Confirm no files are left. fileNames = isoFile.GetFileNames("Archive\*") End If If dirNames.Length > 0 Then For Each name In dirNames ' Delete the Archive directory. isoFile.DeleteDirectory(name) Next name End If dirNames = isoFile.GetDirectoryNames("*") isoFile.Remove() Catch ex As Exception Console.WriteLine(ex.ToString()) End Try End Sub 'DeleteDirectories Public Function SetNewPrefsForUser() As Double Try Dim inputChar As Byte Dim isoFile As IsolatedStorageFile = IsolatedStorageFile.GetStore(IsolatedStorageScope.User Or IsolatedStorageScope.Assembly Or IsolatedStorageScope.Domain, GetType(System.Security.Policy.Url), GetType(System.Security.Policy.Url)) ' If this is not a new user, archive the old preferences and ' overwrite them using the new preferences. If Not Me.myNewPrefs Then If isoFile.GetDirectoryNames("Archive").Length = 0 Then isoFile.CreateDirectory("Archive") Else Dim source As New IsolatedStorageFileStream(Me.userName, FileMode.OpenOrCreate, isoFile) Dim canWrite, canRead As Boolean ' This is the stream from which data will be read. If source.CanRead Then canRead = True Else canRead = False Console.WriteLine("Is the source file readable? " & canRead) Console.WriteLine("Creating new IsolatedStorageFileStream for Archive.") ' Open or create a writable file. Dim target As New IsolatedStorageFileStream("Archive\ " & Me.userName, _ FileMode.OpenOrCreate, FileAccess.Write, FileShare.Write, isoFile) ' This is the stream to which data will be written. If target.CanWrite Then canWrite = True Else canWrite = False Console.WriteLine("Is the target file writable? " & canWrite) target.SetLength(0) 'rewind the target file ' Stream the old file to a new file in the Archive directory. If source.IsAsync And target.IsAsync Then ' IsolatedStorageFileStreams cannot be asynchronous. However, you ' can use the asynchronous BeginRead and BeginWrite functions ' with some possible performance penalty. Console.WriteLine("IsolatedStorageFileStreams cannot be asynchronous.") Else Console.WriteLine("Writing data to the new file.") While source.Position < source.Length inputChar = CByte(source.ReadByte()) target.WriteByte(inputChar) End While ' Determine the size of the IsolatedStorageFileStream ' by checking its Length property. Console.WriteLine(("Total Bytes Read: " & source.Length)) End If ' After you have read and written to the streams, close them. target.Close() source.Close() End If End If ' Open or create a writable file with a maximum size of 10K. Dim isoStream As New IsolatedStorageFileStream(Me.userName, FileMode.OpenOrCreate, _ FileAccess.Write, FileShare.Write, 10240, isoFile) isoStream.SetLength(0) 'Position to overwrite the old data. Dim writer As New StreamWriter(isoStream) ' Update the data based on the new inputs. writer.WriteLine(Me.NewsUrl) writer.WriteLine(Me.SportsUrl) ' Calculate the amount of space used to record this user's preferences. Dim d As Double = Convert.ToDouble(isoFile.CurrentSize) / Convert.ToDouble(isoFile.MaximumSize) Console.WriteLine(("CurrentSize = " & isoFile.CurrentSize.ToString())) Console.WriteLine(("MaximumSize = " & isoFile.MaximumSize.ToString())) ' StreamWriter.Close implicitly closes isoStream. writer.Close() isoFile.Close() Return d Catch ex As Exception Console.WriteLine(ex.ToString()) Return 0.0 End Try End Function 'SetNewPrefsForUser End Class 'LoginPrefs End Namespace 'ISOCS [C#] // This sample demonstrates methods of classes found in the System.IO IsolatedStorage namespace. using System; using System.IO; using System.IO.IsolatedStorage; using System.Security.Policy; [assembly: CLSCompliantAttribute(true)] class ConsoleApp { [STAThread] static void Main(string[] args) { // Prompt the user for their username. Console.WriteLine("Login:"); // Does no error checking. LoginPrefs lp = new LoginPrefs(Console.ReadLine()); if (lp.NewPrefs) { Console.WriteLine("Please set preferences for a new user."); GatherInfoFromUser(lp); // Write the new preferences to storage. double percentUsed = lp.SetPrefsForUser(); Console.WriteLine("Your preferences have been written. Current space used is " + percentUsed.ToString() + " %"); } else { Console.WriteLine("Welcome back."); Console.WriteLine("Your preferences have expired, please reset them."); GatherInfoFromUser(lp); lp.SetNewPrefsForUser(); Console.WriteLine("Your news site has been set to {0}\n and your sports site has been set to {1}.", lp.NewsUrl, lp.SportsUrl); } lp.GetIsoStoreInfo (); Console.WriteLine("Enter 'd' to delete the IsolatedStorage files and exit, or press any other key to exit without deleting files."); string consoleInput = Console.ReadLine(); if (consoleInput.ToLower() == "d") { lp.DeleteFiles(); lp.DeleteDirectories(); } } static void GatherInfoFromUser (LoginPrefs lp ) { Console.WriteLine("Please enter the URL of your news site."); lp.NewsUrl = Console.ReadLine(); Console.WriteLine("Please enter the URL of your sports site."); lp.SportsUrl = Console.ReadLine(); } } public class LoginPrefs { public LoginPrefs(string myUserName) { userName = myUserName; myNewPrefs = GetPrefsForUser(); } string userName; string myNewsUrl; public string NewsUrl { get { return myNewsUrl; } set { myNewsUrl = value; } } string mySportsUrl; public string SportsUrl { get { return mySportsUrl; } set { mySportsUrl = value; } } bool myNewPrefs; public bool NewPrefs { get { return myNewPrefs; } } private bool GetPrefsForUser() { try { // Retrieve an IsolatedStorageFile for the current Domain and Assembly. IsolatedStorageFile isoFile = IsolatedStorageFile.GetStore(IsolatedStorageScope.User | IsolatedStorageScope.Assembly | IsolatedStorageScope.Domain , null, null); IsolatedStorageFileStream isoStream = new IsolatedStorageFileStream( this.userName, FileMode.Open, FileAccess.Read, FileShare.Read); // The code executes to this point only if a file corresponding to the username exists. // Though you can perform operations on the stream, you cannot get a handle to the file. try { IntPtr aFileHandle = isoStream.Handle; Console.WriteLine("A pointer to a file handle has been obtained. " + aFileHandle.ToString() + " " + aFileHandle.GetHashCode()); } catch (Exception e) { // Handle the exception. Console.WriteLine("Expected exception"); Console.WriteLine(e); } StreamReader reader = new StreamReader(isoStream); // Read the data. this.NewsUrl = reader.ReadLine(); this.SportsUrl = reader.ReadLine(); reader.Close(); isoFile.Close(); return false; } catch (System.IO.FileNotFoundException) { // Expected exception if a file cannot be found. This indicates that we have a new user. return true; } } public bool GetIsoStoreInfo () { // Get a User store with type evidence for the current Domain and the Assembly. IsolatedStorageFile isoFile = IsolatedStorageFile.GetStore( IsolatedStorageScope.User | IsolatedStorageScope.Assembly | IsolatedStorageScope.Domain, typeof(System.Security.Policy.Url), typeof(System.Security.Policy.Url)); String [] dirNames = isoFile.GetDirectoryNames("*"); String [] fileNames = isoFile.GetFileNames("*"); // List directories currently in this Isolated Storage. if (dirNames.Length>0) { for (int i=0;i<dirNames.Length;++i) { Console.WriteLine("Directory Name: " + dirNames[i]); } } // List the files currently in this Isolated Storage. // The list represents all users who have personal preferences stored for this application. if (fileNames.Length>0) { for (int i=0;i<fileNames.Length;++i) { Console.WriteLine("File Name: " + fileNames[i]); } } isoFile.Close(); return true; } public double SetPrefsForUser () { try { IsolatedStorageFile isoFile; isoFile = IsolatedStorageFile.GetUserStoreForDomain(); // Open or create a writable file. IsolatedStorageFileStream isoStream = new IsolatedStorageFileStream( this.userName, FileMode.OpenOrCreate, FileAccess.Write, isoFile); StreamWriter writer = new StreamWriter(isoStream); writer.WriteLine(this.NewsUrl); writer.WriteLine(this.SportsUrl); // Calculate the amount of space used to record the user's preferences. double d = isoFile.CurrentSize/isoFile.MaximumSize; Console.WriteLine("CurrentSize = " + isoFile.CurrentSize.ToString()); Console.WriteLine("MaximumSize = " + isoFile.MaximumSize.ToString()); // StreamWriter.Close implicitly closes isoStream. writer.Close(); isoFile.Dispose(); isoFile.Close(); return d; } catch (IsolatedStorageException) { //ToDo: Handle the exception. return 0.0; } } public void DeleteFiles () { try { IsolatedStorageFile isoFile = IsolatedStorageFile.GetStore( IsolatedStorageScope.User | IsolatedStorageScope.Assembly | IsolatedStorageScope.Domain, typeof(System.Security.Policy.Url), typeof(System.Security.Policy.Url)); String [] dirNames = isoFile.GetDirectoryNames("*"); String [] fileNames = isoFile.GetFileNames("*"); // List the files currently in this Isolated Storage. // The list represents all users who have personal // preferences stored for this application. if (fileNames.Length>0) { for (int i=0;i<fileNames.Length;++i) { // Delete the files. isoFile.DeleteFile(fileNames[i]); } // Confirm that no files remain. fileNames = isoFile.GetFileNames("*"); } } catch (Exception e) { Console.WriteLine(e.ToString()); } } // This method deletes directories in the specified Isolated Storage, after first // deleting the files they contain. In this example, the Archive directory is deleted. // There should be no other directories in this Isolated Storage. public void DeleteDirectories() { try { IsolatedStorageFile isoFile = IsolatedStorageFile.GetStore( IsolatedStorageScope.User | IsolatedStorageScope.Assembly | IsolatedStorageScope.Domain, typeof(System.Security.Policy.Url), typeof(System.Security.Policy.Url)); String [] dirNames = isoFile.GetDirectoryNames("*"); String [] fileNames = isoFile.GetFileNames("Archive\\*"); // Delete all the files currently in the Archive directory. if (fileNames.Length>0) { for (int i=0;i<fileNames.Length;++i) { // Delete the files. isoFile.DeleteFile("Archive\\" + fileNames[i]); } // Confirm that no files remain. fileNames = isoFile.GetFileNames("Archive\\*"); } if (dirNames.Length>0) { for (int i=0; i<dirNames.Length; ++i) { // Delete the Archive directory. } } dirNames = isoFile.GetDirectoryNames("*"); isoFile.Remove(); } catch (Exception e) { Console.WriteLine(e.ToString()); } } public double SetNewPrefsForUser () { try { byte inputChar; IsolatedStorageFile isoFile = IsolatedStorageFile.GetStore( IsolatedStorageScope.User | IsolatedStorageScope.Assembly | IsolatedStorageScope.Domain, typeof(System.Security.Policy.Url), typeof(System.Security.Policy.Url)); // If this is not a new user, archive the old preferences and // overwrite them using the new preferences. if (! this.myNewPrefs) { if ( isoFile.GetDirectoryNames("Archive").Length == 0 ) isoFile.CreateDirectory("Archive"); else { IsolatedStorageFileStream source = new IsolatedStorageFileStream(this.userName,FileMode.OpenOrCreate, isoFile); // This is the stream from which data will be read. Console.WriteLine("Is the source file readable? " + (source.CanRead?"true":"false")); Console.WriteLine("Creating new IsolatedStorageFileStream for Archive."); // Open or create a writable file. IsolatedStorageFileStream target = new IsolatedStorageFileStream("Archive\\ " + this.userName, FileMode.OpenOrCreate, FileAccess.Write, FileShare.Write, isoFile); Console.WriteLine("Is the target file writable? " + (target.CanWrite?"true":"false")); // Stream the old file to a new file in the Archive directory. if (source.IsAsync && target.IsAsync) { // IsolatedStorageFileStreams cannot be asynchronous. However, you // can use the asynchronous BeginRead and BeginWrite functions // with some possible performance penalty. Console.WriteLine("IsolatedStorageFileStreams cannot be asynchronous."); } else { Console.WriteLine("Writing data to the new file."); while (source.Position < source.Length) { inputChar = (byte)source.ReadByte(); target.WriteByte(inputChar); } // Determine the size of the IsolatedStorageFileStream // by checking its Length property. Console.WriteLine("Total Bytes Read: " + source.Length); } // After you have read and written to the streams, close them. target.Close(); source.Close(); } } // Open or create a writable file with a maximum size of 10K. IsolatedStorageFileStream isoStream = new IsolatedStorageFileStream(this.userName, FileMode.OpenOrCreate, FileAccess.Write, FileShare.Write, 10240, isoFile); isoStream.Position = 0; // Position to overwrite the old data. StreamWriter writer = new StreamWriter(isoStream); // Update the data based on the new inputs. writer.WriteLine(this.NewsUrl); writer.WriteLine(this.SportsUrl); // Calculate the amount of space used to record this user's preferences. double d = isoFile.CurrentSize/isoFile.MaximumSize; Console.WriteLine("CurrentSize = " + isoFile.CurrentSize.ToString()); Console.WriteLine("MaximumSize = " + isoFile.MaximumSize.ToString()); // StreamWriter.Close implicitly closes isoStream. writer.Close(); isoFile.Close(); return d; } catch (Exception e) { Console.WriteLine(e.ToString()); return 0.0; } } } [C++] // This sample demonstrates methods of classes found in the System.IO IsolatedStorage namespace. #using <mscorlib.dll> using namespace System; using namespace System::IO; using namespace System::IO::IsolatedStorage; using namespace System::Security::Policy; __gc public class LoginPrefs { private: String* userName; String* newsUrl; String* sportsUrl; bool newPrefs; public: bool GetPrefsForUser() { try { // Retrieve an IsolatedStorageFile for the current Domain and Assembly. IsolatedStorageFile* isoFile = IsolatedStorageFile::GetStore( static_cast<IsolatedStorageScope>(IsolatedStorageScope::User | IsolatedStorageScope::Assembly | IsolatedStorageScope::Domain), (Type*)0, 0); IsolatedStorageFileStream* isoStream = new IsolatedStorageFileStream(this->userName, FileMode::Open, FileAccess::ReadWrite, isoFile); // farThe code executes to this point only if a file corresponding to the username exists. // Though you can perform operations on the stream, you cannot get a handle to the file. try { IntPtr aFileHandle = isoStream->Handle; Console::WriteLine(S"A pointer to a file handle has been obtained. {0} {1}", __box(aFileHandle), __box(aFileHandle.GetHashCode())); } catch (Exception* e) { // Handle the exception. Console::WriteLine(S"Expected exception"); Console::WriteLine(e->ToString()); } StreamReader* reader = new StreamReader(isoStream); // Read the data. this->NewsUrl = reader->ReadLine(); this->SportsUrl = reader->ReadLine(); reader->Close(); isoFile->Close(); isoStream->Close(); return false; } catch (Exception* e) { // Expected exception if a file cannot be found. This indicates that we have a new user. String* errorMessage = e->ToString(); return true; } } bool GetIsoStoreInfo () { // Get a User store with type evidence for the current Domain and the Assembly. IsolatedStorageFile* isoFile = IsolatedStorageFile::GetStore( static_cast<IsolatedStorageScope>(IsolatedStorageScope::User | IsolatedStorageScope::Assembly | IsolatedStorageScope::Domain), __typeof(System::Security::Policy::Url), __typeof(System::Security::Policy::Url)); String* dirNames[] = isoFile->GetDirectoryNames(S"*"); String* fileNames[] = isoFile->GetFileNames(S"*"); // List directories currently in this Isolated Storage. if (dirNames->Length>0) { for (int i=0;i<dirNames->Length;++i) { Console::WriteLine(S"Directory Name: {0}", dirNames[i]); } } // List the files currently in this Isolated Storage. // The list represents all users who have personal preferences stored for this application. if (fileNames->Length>0) { for (int i=0;i<fileNames->Length;++i) { Console::WriteLine(S"File Name: {0}", fileNames[i]); } } isoFile->Close(); return true; } double SetPrefsForUser () { try { IsolatedStorageFile* isoFile; isoFile = IsolatedStorageFile::GetUserStoreForDomain(); // Open or create a writable file. IsolatedStorageFileStream* isoStream = new IsolatedStorageFileStream( this->userName, FileMode::OpenOrCreate, FileAccess::Write, isoFile); StreamWriter* writer = new StreamWriter(isoStream); writer->WriteLine(this->NewsUrl); writer->WriteLine(this->SportsUrl); // Calculate the amount of space used to record the user's preferences. double d = isoFile->CurrentSize/isoFile->MaximumSize; Console::WriteLine(S"CurrentSize = {0}", isoFile->CurrentSize.ToString()); Console::WriteLine(S"MaximumSize = {0}", isoFile->MaximumSize.ToString()); writer->Close(); isoFile->Close(); isoStream->Close(); return d; } catch (Exception* e) { //ToDo: Handle the exception. Console::WriteLine(e->ToString()); return 0.0; } } void DeleteFiles () { try { IsolatedStorageFile* isoFile = IsolatedStorageFile::GetStore( static_cast<IsolatedStorageScope>(IsolatedStorageScope::User | IsolatedStorageScope::Assembly | IsolatedStorageScope::Domain), __typeof(System::Security::Policy::Url), __typeof(System::Security::Policy::Url)); String* dirNames[] = isoFile->GetDirectoryNames(S"*"); String* fileNames[] = isoFile->GetFileNames(S"*"); // List the files currently in this Isolated Storage. // The list represents all users who have personal // preferences stored for this application. if (fileNames->Length>0) { for (int i=0;i<fileNames->Length;++i) { //Delete the files. isoFile->DeleteFile(fileNames[i]); } // Confirm that no files remain. fileNames = isoFile->GetFileNames(S"*"); } isoFile->Close(); } catch (Exception* e) { Console::WriteLine(e->ToString()); } } // This method deletes directories in the specified Isolated Storage, after first // deleting the files they contain. In this example, the Archive directory is deleted. // There should be no other directories in this Isolated Storage. void DeleteDirectories() { try { IsolatedStorageFile* isoFile = IsolatedStorageFile::GetStore( static_cast<IsolatedStorageScope>(IsolatedStorageScope::User | IsolatedStorageScope::Assembly | IsolatedStorageScope::Domain), __typeof(System::Security::Policy::Url), __typeof(System::Security::Policy::Url)); String* dirNames[] = isoFile->GetDirectoryNames(S"*"); String* fileNames[] = isoFile->GetFileNames(S"Archive\\*"); // Delete the current files within the Archive directory. if (fileNames->Length>0) { for (int i=0;i<fileNames->Length;++i) { //delete files isoFile->DeleteFile((S"Archive\\{0}", fileNames[i])); } //Confirm no files are left. fileNames = isoFile->GetFileNames(S"Archive\\*"); } if (dirNames->Length>0) { for (int i=0; i<dirNames->Length; ++i) { // Delete the Archive directory. isoFile->DeleteDirectory(dirNames[i]); } } dirNames = isoFile->GetDirectoryNames(S"*"); isoFile->Remove(); } catch (Exception* e) { Console::WriteLine(e->ToString()); } } double SetNewPrefsForUser () { try { Byte inputChar; IsolatedStorageFile* isoFile = IsolatedStorageFile::GetStore( static_cast<IsolatedStorageScope>(IsolatedStorageScope::User | IsolatedStorageScope::Assembly | IsolatedStorageScope::Domain), __typeof(System::Security::Policy::Url), __typeof(System::Security::Policy::Url)); // If this is not a new user, archive the old preferences and // overwrite them using the new preferences. if (! this->NewPrefs) { if ( isoFile->GetDirectoryNames(S"Archive")->Length == 0 ) isoFile->CreateDirectory(S"Archive"); else { // This is the stream to which data will be written. IsolatedStorageFileStream* source = new IsolatedStorageFileStream(this->userName,FileMode::OpenOrCreate, isoFile); // This is the stream from which data will be read. Console::WriteLine(S"Is the source file readable? {0}", (source->CanRead ? S"true" : S"false")); Console::WriteLine(S"Creating new IsolatedStorageFileStream for Archive."); // Open or create a writable file. IsolatedStorageFileStream* target = new IsolatedStorageFileStream((S"Archive\\ {0}", this->userName), FileMode::OpenOrCreate, FileAccess::Write, FileShare::Write, isoFile); Console::WriteLine(S"Is the target file writable? {0}", (target->CanWrite ? S"true" : S"false")); // Stream the old file to a new file in the Archive directory. if (source->IsAsync && target->IsAsync) { // IsolatedStorageFileStreams cannot be asynchronous. However, you // can use the asynchronous BeginRead and BeginWrite functions // with some possible performance penalty. Console::WriteLine(S"IsolatedStorageFileStreams cannot be asynchronous."); } else { Console::WriteLine(S"Writing data to the new file."); while (source->Position < source->Length) { inputChar = (Byte)source->ReadByte(); target->WriteByte((Byte)source->ReadByte()); } // Determine the size of the IsolatedStorageFileStream // by checking its Length property. Console::WriteLine(S"Total Bytes Read: {0}", source->Length.ToString()); } // After you have read and written to the streams, close them. target->Close(); source->Close(); } } // Open or create a writable file, no larger than 10k IsolatedStorageFileStream* isoStream = new IsolatedStorageFileStream(this->userName, FileMode::OpenOrCreate, FileAccess::Write, FileShare::Write, 10240, isoFile); isoStream->Position = 0; // Position to overwrite the old data. StreamWriter* writer = new StreamWriter(isoStream); // Update the data based on the new inputs. writer->WriteLine(this->NewsUrl); writer->WriteLine(this->SportsUrl); // Calculate the amount of space used to record this user's preferences. double d = isoFile->CurrentSize/isoFile->MaximumSize; Console::WriteLine(S"CurrentSize = {0}", isoFile->CurrentSize.ToString()); Console::WriteLine(S"MaximumSize = {0}", isoFile->MaximumSize.ToString()); // StreamWriter.Close implicitly closes isoStream. writer->Close(); isoFile->Close(); return d; } catch (Exception* e) { Console::WriteLine(e->ToString()); return 0.0; } } LoginPrefs(String* aUserName) { userName = aUserName; newPrefs = GetPrefsForUser(); } __property String* get_NewsUrl() { return newsUrl; } __property void set_NewsUrl(String* value) { newsUrl = value; } __property String* get_SportsUrl() { return sportsUrl; } __property void set_SportsUrl(String* value) { sportsUrl = value; } __property bool get_NewPrefs() { return newPrefs; } }; void GatherInfoFromUser (LoginPrefs* lp ) { Console::WriteLine(S"Please enter the URL of your news site."); lp->NewsUrl = Console::ReadLine(); Console::WriteLine(S"Please enter the URL of your sports site."); lp->SportsUrl = Console::ReadLine(); } int main() { // Prompt the user for their username. Console::WriteLine(S"Enter your login ID:"); // Does no error checking. LoginPrefs* lp = new LoginPrefs(Console::ReadLine()); if (lp->NewPrefs) { Console::WriteLine(S"Please set preferences for a new user."); GatherInfoFromUser(lp); // Write the new preferences to storage. double percentUsed = lp->SetPrefsForUser(); Console::WriteLine(S"Your preferences have been written. Current space used is {0}%", __box(percentUsed)); } else { Console::WriteLine(S"Welcome back."); Console::WriteLine(S"Your preferences have expired, please reset them."); GatherInfoFromUser(lp); lp->SetNewPrefsForUser(); Console::WriteLine(S"Your news site has been set to {0}\n and your sports site has been set to {1}.", lp->NewsUrl, lp->SportsUrl); } lp->GetIsoStoreInfo (); Console::WriteLine(S"Enter 'd' to delete the IsolatedStorage files and exit, or press any other key to exit without deleting files."); String* consoleInput = Console::ReadLine(); if (consoleInput->Equals(S"d")) { lp->DeleteFiles(); lp->DeleteDirectories(); } }
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Requirements
Namespace: System.IO.IsolatedStorage
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family
Assembly: Mscorlib (in Mscorlib.dll)
See Also
IsolatedStorageFileStream Members | System.IO.IsolatedStorage Namespace