IsolatedStorageFileStream.Handle Свойство

Определение

Пространство имен:

System.IO.IsolatedStorage

Сборка:

System.IO.IsolatedStorage.dll

Исходный код:

IsolatedStorageFileStream.cs

Внимание!

IsolatedStorageFileStream.Handle has been deprecated. Use IsolatedStorageFileStream's SafeFileHandle property instead.

Возвращает дескриптор файла для файла, инкапсулируемого текущим объектом IsolatedStorageFileStream. Доступ к этому свойству для объекта IsolatedStorageFileStream не разрешен. Создается исключение IsolatedStorageException.

public:
 virtual property IntPtr Handle { IntPtr get(); };

[System.Obsolete("IsolatedStorageFileStream.Handle has been deprecated. Use IsolatedStorageFileStream's SafeFileHandle property instead.")]
public override IntPtr Handle { get; }

[<System.Obsolete("IsolatedStorageFileStream.Handle has been deprecated. Use IsolatedStorageFileStream's SafeFileHandle property instead.")>]
member this.Handle : nativeint

Public Overrides ReadOnly Property Handle As IntPtr

Значение свойства

IntPtr

nativeint

Дескриптор файла для файла, инкапсулируемого текущим объектом IsolatedStorageFileStream.

Атрибуты

ObsoleteAttribute

Исключения

IsolatedStorageException

Свойство Handle всегда создает это исключение.

Примеры

В следующем примере кода демонстрируется Handle свойство .

[SecurityPermissionAttribute(SecurityAction::Demand, Flags=SecurityPermissionFlag::UnmanagedCode)]
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^)nullptr, nullptr );
      IsolatedStorageFileStream^ isoStream = gcnew 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( "A pointer to a file handle has been obtained. {0} {1}", aFileHandle, aFileHandle.GetHashCode() );
      }
      catch ( Exception^ e ) 
      {
         
         // Handle the exception.
         Console::WriteLine( "Expected exception" );
         Console::WriteLine( e->ToString() );
      }

      StreamReader^ reader = gcnew 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;
   }

}

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("substituteUsername",
            System.IO.FileMode.Open,
            System.IO.FileAccess.Read,
             System.IO.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
        {

            SafeFileHandle aFileHandle = isoStream.SafeFileHandle;
            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;
    }
}

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("substituteUsername", System.IO.FileMode.Open, _
            System.IO.FileAccess.Read, System.IO.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 SafeFileHandle = isoStream.SafeFileHandle
            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

Комментарии

Для получения дополнительной информации см. Handle.