OpenFileDialog.ReadOnlyChecked Property


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Gets or sets a value indicating whether the read-only check box is selected.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

Public Property ReadOnlyChecked As Boolean

Property Value

Type: System.Boolean

true if the read-only check box is selected; otherwise, false. The default value is false.

The ReadOnlyChecked state does not affect the read/write mode that OpenFileDialog.OpenFile uses to open a file selected in the dialog box. OpenFile will always open the file in read-only mode.

The ShowReadOnly property must be set before in order for the read-only check box to appear in the dialog box.

The following code example demonstrates the use of the ReadOnlyChecked property. This example displays the OpenFileDialog box with the ShowReadOnly property set to true. If the user clicks the option to open the file in read-only mode, the ReadOnlyChecked property evaluates to true, and the OpenFile method is used to open the file. Otherwise, the FileStream class is used to open the file in read/write mode.

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.
            If (DlgOpenFile.ReadOnlyChecked = True) Then
                Return DlgOpenFile.OpenFile()
                ' Otherwise, opens the file with read/write access.
                Path = DlgOpenFile.FileName
                Return New FileStream(Path, System.IO.FileMode.Open, _
            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

.NET Framework
Available since 1.1
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