IsolatedStorageFile.CreateDirectory(String) Metodo

Definizione

Spazio dei nomi:

System.IO.IsolatedStorage

Assembly:

System.IO.IsolatedStorage.dll

Origine:

IsolatedStorageFile.cs

Crea una directory nell'ambito dello spazio di memorizzazione isolato.

public:
 void CreateDirectory(System::String ^ dir);

public void CreateDirectory (string dir);

member this.CreateDirectory : string -> unit

Public Sub CreateDirectory (dir As String)

Parametri

dir

String

Percorso relativo della directory da creare nell'ambito dello spazio di memorizzazione isolato.

Eccezioni

IsolatedStorageException

Il codice corrente non dispone di autorizzazioni sufficienti per creare una directory dello spazio di memorizzazione isolato.

ArgumentNullException

Il percorso della directory è null.

Esempio

Nell'esempio di codice seguente viene illustrato il CreateDirectory metodo . Per il contesto completo di questo esempio, vedere la IsolatedStorageFile panoramica.

double SetNewPrefsForUser()
{
   try
   {
      Byte inputChar;
      IsolatedStorageFile^ isoFile = IsolatedStorageFile::GetStore( static_cast<IsolatedStorageScope>(IsolatedStorageScope::User | IsolatedStorageScope::Assembly | IsolatedStorageScope::Domain), System::Security::Policy::Url::typeid, System::Security::Policy::Url::typeid );
      
      // If this is not a new user, archive the old preferences and 
      // overwrite them using the new preferences.
      if (  !this->NewPrefs )
      {
         if ( isoFile->GetDirectoryNames( "Archive" )->Length == 0 )
                     isoFile->CreateDirectory( "Archive" );
         else
         {
            
            // This is the stream to which data will be written.
            IsolatedStorageFileStream^ source = gcnew IsolatedStorageFileStream( this->userName,FileMode::OpenOrCreate,isoFile );
            
            // This is the stream from which data will be read.
            Console::WriteLine( "Is the source file readable?  {0}", (source->CanRead ? (String^)"true" : "false") );
            Console::WriteLine( "Creating new IsolatedStorageFileStream for Archive." );
            
            // Open or create a writable file.
            IsolatedStorageFileStream^ target = gcnew IsolatedStorageFileStream( String::Concat("Archive\\",this->userName),FileMode::OpenOrCreate,FileAccess::Write,FileShare::Write,isoFile );
            
            Console::WriteLine( "Is the target file writable? {0}", (target->CanWrite ? (String^)"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( (Byte)source->ReadByte() );
               }
               
               // Determine the size of the IsolatedStorageFileStream
               // by checking its Length property.
               Console::WriteLine( "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 = gcnew IsolatedStorageFileStream( this->userName,FileMode::OpenOrCreate,FileAccess::Write,FileShare::Write,10240,isoFile );
      
      isoStream->Position = 0; // Position to overwrite the old data.

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.

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.

Commenti

La directory creata inizialmente non contiene file. Se la directory esiste già, il CreateDirectory metodo restituisce senza creare una nuova directory. L'esempio Procedura: Creare file e directory nell'archiviazione isolata illustra l'uso del CreateDirectory metodo

Vedi anche

• Spazio di memorizzazione isolato