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IsolatedStorageFile.CreateDirectory Method

Creates a directory in the isolated storage scope.

[Visual Basic]
Public Sub CreateDirectory( _
   ByVal dir As String _
)
[C#]
public void CreateDirectory(
 string dir
);
[C++]
public: void CreateDirectory(
 String* dir
);
[JScript]
public function CreateDirectory(
   dir : String
);

Parameters

dir
The relative path of the directory to create within the isolated storage scope.

Exceptions

Exception Type Condition
IsolatedStorageException The current code has insufficient permissions to create isolated storage directory.
ArgumentNullException The directory path is a null reference (Nothing in Visual Basic).

Remarks

The created directory initially contains no files. The Creating Files and Directories example demonstrates the use of the CreateDirectory method

Example

[Visual Basic, C#, C++] The following code example demonstrates the CreateDirectory method. For the complete context of this example, see the IsolatedStorageFile overview.

[Visual Basic] 
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.

[C#] 
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.

[C++] 
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.

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

.NET Framework Security: 

See Also

IsolatedStorageFile Class | IsolatedStorageFile Members | System.IO.IsolatedStorage Namespace

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