This documentation is archived and is not being maintained.

FileDialogPermission Class

Controls the ability to access files or folders through a File dialog box. This class cannot be inherited.

Namespace:  System.Security.Permissions
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public NotInheritable Class FileDialogPermission _
	Inherits CodeAccessPermission _
	Implements IUnrestrictedPermission
'Usage
Dim instance As FileDialogPermission

This permission is typically used to provide limited access to user-specified files when FileIOPermission is not granted.

The following code example demonstrates the behavior of the FileDialogPermission class methods.

The example is intended to show how the methods perform if you execute the methods from your code. In general, the methods of permission classes are used by the security infrastructure; they are not typically used in applications.

For an example that shows the use of the FileDialogPermission class to demand permission for a specific FileDialogPermissionAccess enumeration value, see the FileDialogPermission(FileDialogPermissionAccess) constructor.

Imports System
Imports System.Security
Imports System.Security.Permissions



<assembly: CLSCompliant(True)>


Public Class FileDialogPermissionDemo
    Private fileDialogPerm1 As New FileDialogPermission(FileDialogPermissionAccess.Open)
    Private fileDialogPerm2 As New FileDialogPermission(FileDialogPermissionAccess.OpenSave)
    Private fileDialogPerm3 As New FileDialogPermission(PermissionState.None)

    ' IsSubsetOf determines whether the current permission is a subset of the 
    ' specified permission. 
    Private Function IsSubsetOfDemo() As Boolean  
        Dim returnValue As Boolean = True 


        If fileDialogPerm1.IsSubsetOf(fileDialogPerm2) Then
            Console.WriteLine(fileDialogPerm1.Access.ToString() + " is a subset of " _
            + fileDialogPerm2.Access.ToString())
        Else
            Console.WriteLine(fileDialogPerm1.Access.ToString + " is not a subset of " + _
            fileDialogPerm2.Access.ToString())
        End If 

        Return returnValue

    End Function 'IsSubsetOfDemo

    ' Union creates a new permission that is the union of the current permission and the 
    ' specified permission. 
    Private Function UnionDemo() As Boolean  
        Dim returnValue As Boolean = True

        fileDialogPerm3 = CType(fileDialogPerm1.Union(fileDialogPerm2), FileDialogPermission)

        If fileDialogPerm3 Is Nothing Then
            Console.WriteLine("The union of " + fileDialogPerm1.Access.ToString() + _
            " and " + fileDialogPerm2.Access.ToString() + " is null.")
        Else
            Console.WriteLine("The union of " + fileDialogPerm1.Access.ToString() + _
            " and " + fileDialogPerm2.Access.ToString() + " = " + _
            CType(fileDialogPerm3, FileDialogPermission).Access.ToString())
        End If 

        Return returnValue

    End Function 'UnionDemo

    ' Intersect creates and returns a new permission that is the intersection of the current 
    ' permission and the permission specified. 
    Private Function IntersectDemo() As Boolean  
        Dim returnValue As Boolean = True

        fileDialogPerm3 = CType(fileDialogPerm1.Intersect(fileDialogPerm2), FileDialogPermission)
        If Not (fileDialogPerm3 Is Nothing) Then
            Console.WriteLine("The intersection of " + fileDialogPerm1.Access.ToString() + " and " _
            + fileDialogPerm2.Access.ToString() + " = " + CType(fileDialogPerm3, _
            FileDialogPermission).Access.ToString())
        Else
            Console.WriteLine("The intersection of " + fileDialogPerm1.Access.ToString() + " and " + _
            fileDialogPerm2.Access + " is null.")
        End If 

        Return returnValue

    End Function 'IntersectDemo

    ' Copy creates and returns an identical copy of the current permission. 
    Private Function CopyDemo() As Boolean  

        Dim returnValue As Boolean = True

        fileDialogPerm2 = CType(fileDialogPerm1.Copy(), FileDialogPermission)
        Console.WriteLine("Result of copy = " + fileDialogPerm2.ToString())

        Return returnValue

    End Function 'CopyDemo

    ' ToXml creates an XML encoding of the permission and its current state; FromXml reconstructs a 
    ' permission with the specified state from the XML encoding. 
    Private Function ToFromXmlDemo() As Boolean  

        Dim returnValue As Boolean = True

        fileDialogPerm2 = New FileDialogPermission(PermissionState.None)
        fileDialogPerm2.FromXml(fileDialogPerm1.ToXml())
        Console.WriteLine("Result of ToFromXml = " + fileDialogPerm2.ToString())

        Return returnValue

    End Function 'ToFromXmlDemo

    ' Invoke all demos. 
    Public Function RunDemo() As Boolean 
        Dim returnCode As Boolean = True 
        Dim tempReturnCode As Boolean 

        ' Call the IsSubsetOf demo. 
        If IsSubsetOfDemo() Then
            Console.Out.WriteLine("IsSubsetOf demo completed successfully.")
            tempReturnCode = True 
        Else
            Console.Out.WriteLine("IsSubsetOf demo failed.")
            tempReturnCode = False 
        End If
        returnCode = tempReturnCode And returnCode

        ' Call the Union demo. 
        If UnionDemo() Then
            Console.Out.WriteLine("Union demo completed successfully.")
            tempReturnCode = True 
        Else
            Console.Out.WriteLine("Union demo failed.")
            tempReturnCode = False 
        End If
        returnCode = tempReturnCode And returnCode

        ' Call the Intersect demo.	 
        If IntersectDemo() Then
            Console.Out.WriteLine("Intersect demo completed successfully.")
            tempReturnCode = True 
        Else
            Console.Out.WriteLine("Intersect demo failed.")
            tempReturnCode = False 
        End If
        returnCode = tempReturnCode And returnCode


        ' Call the Copy demo.	 
        If CopyDemo() Then
            Console.Out.WriteLine("Copy demo completed successfully.")
            tempReturnCode = True 
        Else
            Console.Out.WriteLine("Copy demo failed.")
            tempReturnCode = False 
        End If
        returnCode = tempReturnCode And returnCode

        ' Call the ToFromXml demo.	 
        If ToFromXmlDemo() Then
            Console.Out.WriteLine("ToFromXml demo completed successfully.")
            tempReturnCode = True 
        Else
            Console.Out.WriteLine("ToFromXml demo failed.")
            tempReturnCode = False 
        End If
        returnCode = tempReturnCode And returnCode

        Return returnCode
    End Function 

    ' Test harness. 
    Public Shared Sub Main(ByVal args() As String) 
        Try 
            Dim democase As New FileDialogPermissionDemo()
            Dim returnCode As Boolean = democase.RunDemo()
            If returnCode Then
                Console.Out.WriteLine("FileDialogPermission demo completed successfully.")
                Console.Out.WriteLine("Press the Enter key to exit.")
                Dim consoleInput As String = Console.ReadLine()
                System.Environment.ExitCode = 100
            Else
                Console.Out.WriteLine("FileDialogPermission demo failed.")
                Console.Out.WriteLine("Press the Enter key to exit.")
                Dim consoleInput As String = Console.ReadLine()
                System.Environment.ExitCode = 101
            End If 
        Catch e As Exception
            Console.Out.WriteLine("FileDialogPermission failed.")
            Console.WriteLine(e.ToString())
            Console.Out.WriteLine("Press the Enter key to exit.")
            Dim consoleInput As String = Console.ReadLine()
            System.Environment.ExitCode = 101
        End Try 

    End Sub 'Main
End Class 'FileDialogPermissionDemo

System.Object
  System.Security.CodeAccessPermission
    System.Security.Permissions.FileDialogPermission

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
Show: