OpenFileDialog.ReadOnlyChecked Eigenschaft

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Ruft einen Wert ab, der angibt, ob das Kontrollkästchen für den Schreibschutz aktiviert ist, oder legt diesen fest.

public:
 property bool ReadOnlyChecked { bool get(); void set(bool value); };

public bool ReadOnlyChecked { get; set; }

member this.ReadOnlyChecked : bool with get, set

Public Property ReadOnlyChecked As Boolean

Eigenschaftswert

Boolean

true, wenn das Kontrollkästchen für den Schreibschutz aktiviert ist, andernfalls false. Der Standardwert ist false.

Beispiele

Im folgenden Codebeispiel wird die Verwendung des ReadOnlyChecked-Attributs veranschaulicht. In diesem Beispiel wird das OpenFileDialog Feld angezeigt, in dem die ShowReadOnly -Eigenschaft auf festgelegt ist true. Wenn der Benutzer auf die Option klickt, um die Datei im schreibgeschützten Modus zu öffnen, wird die ReadOnlyChecked -Eigenschaft zu trueausgewertet, und die OpenFile -Methode wird verwendet, um die Datei zu öffnen. Andernfalls wird die FileStream -Klasse verwendet, um die Datei im Lese-/Schreibmodus zu öffnen.

private:
   FileStream^ OpenFile()
   {
      // Displays an OpenFileDialog and shows the read/only files.
      OpenFileDialog^ dlgOpenFile = gcnew OpenFileDialog;
      dlgOpenFile->ShowReadOnly = true;
      if ( dlgOpenFile->ShowDialog() == ::DialogResult::OK )
      {
         // If ReadOnlyChecked is true, uses the OpenFile method to
         // open the file with read/only access.
         if ( dlgOpenFile->ReadOnlyChecked == true )
         {
            return dynamic_cast<FileStream^>(dlgOpenFile->OpenFile());
         }
         // Otherwise, opens the file with read/write access.
         else
         {
            String^ path = dlgOpenFile->FileName;
            return gcnew FileStream( path,System::IO::FileMode::Open,System::IO::FileAccess::ReadWrite );
         }
      }

      return nullptr;
   }

private FileStream OpenFile()
{
    // Displays an OpenFileDialog and shows the read/only files.

    OpenFileDialog dlgOpenFile = new OpenFileDialog();
    dlgOpenFile.ShowReadOnly = true;

    if(dlgOpenFile.ShowDialog() == DialogResult.OK)
    {

        // If ReadOnlyChecked is true, uses the OpenFile method to
        // open the file with read/only access.
        string path = null;

        try {
            if(dlgOpenFile.ReadOnlyChecked == true)
            {
                return (FileStream)dlgOpenFile.OpenFile();
            }

            // Otherwise, opens the file with read/write access.
            else
            {
                path = dlgOpenFile.FileName;
                return new FileStream(path, System.IO.FileMode.Open,
                            System.IO.FileAccess.ReadWrite);
            }
        } catch (SecurityException ex)
            {
                // The user lacks appropriate permissions to read files, discover paths, etc.
                MessageBox.Show("Security error. Please contact your administrator for details.\n\n" +
                    "Error message: " + ex.Message + "\n\n" +
                    "Details (send to Support):\n\n" + ex.StackTrace
                );
            }
            catch (Exception ex)
            {
                // Could not load the image - probably related to Windows file system permissions.
                MessageBox.Show("Cannot display the image: " + path.Substring(path.LastIndexOf('\\'))
                    + ". You may not have permission to read the file, or " +
                    "it may be corrupt.\n\nReported error: " + ex.Message);
            }
    }

    return null;
}

Private Function OpenFile() As FileStream

    ' Displays an OpenFileDialog and shows the read/only files.

    Dim DlgOpenFile As New OpenFileDialog()
    DlgOpenFile.ShowReadOnly = True

    If DlgOpenFile.ShowDialog() = System.Windows.Forms.DialogResult.OK Then
        Dim path As New String("")

        ' If ReadOnlyChecked is true, uses the OpenFile method to
        ' open the file with read/only access.
        Try
            If (DlgOpenFile.ReadOnlyChecked = True) Then
                Return DlgOpenFile.OpenFile()
            Else
                ' Otherwise, opens the file with read/write access.
                Path = DlgOpenFile.FileName
                Return New FileStream(Path, System.IO.FileMode.Open, _
                        System.IO.FileAccess.ReadWrite)
            End If
        Catch SecEx As SecurityException
            ' The user lacks appropriate permissions to read files, discover paths, etc.
            MessageBox.Show("Security error. Please contact your administrator for details.\n\n" & _
                "Error message: " & SecEx.Message * "\n\n" & _
                "Details (send to Support):\n\n" & SecEx.StackTrace)
        Catch Ex As Exception
            ' Could not load the image - probably related to Windows file system permissions.
            MessageBox.Show("Cannot display the image: " & path.Substring(path.LastIndexOf("\\")) & _
                     ". You may not have permission to read the file, or " & _
                    "it may be corrupt.\n\nReported error: " + ex.Message)
        End Try
    End If

    Return Nothing
End Function

Hinweise

Der ReadOnlyChecked Zustand wirkt sich nicht auf den Lese-/Schreibmodus aus, OpenFileDialog.OpenFile der zum Öffnen einer im Dialogfeld ausgewählten Datei verwendet wird. OpenFile öffnet die Datei immer im schreibgeschützten Modus.

Die ShowReadOnly -Eigenschaft muss vorher festgelegt werden, damit das schreibgeschützte Kontrollkästchen im Dialogfeld angezeigt wird.

Weitere Informationen

• ShowReadOnly