IsolatedStorageFileStream.Handle 属性

定义

命名空间:

System.IO.IsolatedStorage

程序集:

System.IO.IsolatedStorage.dll

Source:

IsolatedStorageFileStream.cs

注意

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

获取当前 IsolatedStorageFileStream 对象封装的文件的文件句柄。 不允许在 IsolatedStorageFileStream 对象上访问此属性，如果访问，将引发 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

属性值

IntPtr

nativeint

当前 IsolatedStorageFileStream 对象封装的文件的文件句柄。

属性

ObsoleteAttribute

例外

IsolatedStorageException

Handle 属性始终生成此异常。

示例

下面的代码示例演示 了 Handle 属性。

[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

注解

有关详细信息，请参阅 Handle。