CodeAccessPermission.RevertAll 方法

导致当前框架先前的所有重写都被移除，不再有效。

**命名空间:**System.Security
**程序集:**mscorlib（在 mscorlib.dll 中）

语法

声明
Public Shared Sub RevertAll
用法

CodeAccessPermission.RevertAll

public static void RevertAll ()

public:
static void RevertAll ()

public static void RevertAll ()

public static function RevertAll ()

异常

异常类型	条件
ExecutionEngineException	当前框架没有上一个 Assert、Deny 和 PermitOnly。

备注

如果当前框架没有重写（Assert、Deny 或 PermitOnly），则引发 ExecutionEngineException。

示例

下面的代码示例演示如何使用 RevertAll 方法来恢复以前对当前框架的重写。

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



Class UIPermissions

    Public Shared Sub Main()
        Try
            ' Create a new UIPermission that allows access only to OwnClipboard.
            Dim clipboardPermission As New UIPermission(UIPermissionClipboard.OwnClipboard)
            ' Deny access to OwnClipboard.
            Console.WriteLine("Denying access to OwnClipboard")
            clipboardPermission.Deny()
            ' Demand access to files in the specified path.
            DemandOwnClipboardAccess()
            ' Revert the Deny.
            Console.WriteLine("Reverting the Deny.")
            CodeAccessPermission.RevertDeny()
            DemandOwnClipboardAccess()
            ' Grant access only to OwnClipboard.
            Console.WriteLine("Granting permission only for OwnClipboard access.")
            clipboardPermission.PermitOnly()
            DemandAllClipboardAccess()
            ' Revert the PermitOnly with a call to RevertPermitOnly.
            Console.WriteLine("Reverting the PermitOnly.")
            CodeAccessPermission.RevertPermitOnly()
            DemandAllClipboardAccess()
            ' Permit access only to OwnClipboard.
            clipboardPermission.PermitOnly()
            DemandAllClipboardAccess()
            ' Revert the PermitOnly with a call to RevertAll.
            Console.WriteLine("Reverting the PermitOnly using RevertAll.")
            CodeAccessPermission.RevertAll()
            DemandAllClipboardAccess()

            Console.WriteLine("This sample completed successfully; " + _
                "press Enter to exit.")
            Console.ReadLine()
        Catch e As Exception
            Console.WriteLine("Unexpected exception thrown: " + vbLf + e.ToString())
            Console.ReadLine()
        End Try

    End Sub 'Main


    ' Determine whether OwnClipboard can be accessed.
    Private Shared Sub DemandOwnClipboardAccess()
        Try
            ' Create a new UIPermission that allows access to OwnClipboard.
            Dim clipboardPermission As New UIPermission(UIPermissionClipboard.OwnClipboard)

            ' Verify that callers higher in the stack have been granted
            ' the permission.
            Console.WriteLine("Demanding OwnClipboard access.")
            clipboardPermission.Demand()
            Console.WriteLine("The demand was successful")
        Catch ex As SecurityException
            Console.WriteLine("A security exception was thrown while " + _
                "demanding OwnClipboard access permission " + vbLf)
            Console.WriteLine(ex.Message)
        Catch ex As Exception
            Console.WriteLine("A fatal exception occurred:" + vbLf + ex.ToString())
        End Try

    End Sub 'DemandOwnClipboardAccess


    ' Determine whether OwnClipboard can be accessed.
    Private Shared Sub DemandAllClipboardAccess()
        Try
            ' Create a new UIPermission that allows access to OwnClipboard.
            Dim clipboardPermission As New UIPermission(UIPermissionClipboard.AllClipboard)

            ' Verify that callers higher in the stack have been granted
            ' the permission.
            Console.WriteLine("Demanding AllClipboard access.")
            clipboardPermission.Demand()
            Console.WriteLine("The demand was successful")
        Catch ex As SecurityException
            Console.WriteLine("A security exception was thrown while " + _
                "demanding AllClipboard access permission " + vbLf)
            Console.WriteLine(ex.Message)
        Catch ex As Exception
            Console.WriteLine("A fatal exception occurred:" + vbLf + ex.ToString())
        End Try

    End Sub 'DemandAllClipboardAccess
End Class 'UIPermissions

using System;
using System.Security;
using System.Security.Permissions;
using System.IO;

class UIPermissions
{
    public static void Main()
    {
        try
        {
            // Create a new UIPermission that allows access only to OwnClipboard.
            UIPermission clipboardPermission = new UIPermission(UIPermissionClipboard.OwnClipboard);
            // Deny access to OwnClipboard.
            Console.WriteLine("Denying access to OwnClipboard");
            clipboardPermission.Deny();
            // Demand access to files in the specified path.
            DemandOwnClipboardAccess();
            // Revert the Deny.
            Console.WriteLine("Reverting the Deny.");
            CodeAccessPermission.RevertDeny();
            DemandOwnClipboardAccess();
            // Grant access only to OwnClipboard.
            Console.WriteLine("Granting permission only for OwnClipboard access.");
            clipboardPermission.PermitOnly();
            DemandAllClipboardAccess();
            // Revert the PermitOnly with a call to RevertPermitOnly.
            Console.WriteLine("Reverting the PermitOnly.");
            CodeAccessPermission.RevertPermitOnly();
            DemandAllClipboardAccess();
            // Permit access only to OwnClipboard.
            clipboardPermission.PermitOnly();
            DemandAllClipboardAccess();
            // Revert the PermitOnly with a call to RevertAll.
            Console.WriteLine("Reverting the PermitOnly using RevertAll.");
            CodeAccessPermission.RevertAll();
            DemandAllClipboardAccess();


            Console.WriteLine("This sample completed successfully; " +
                "press Enter to exit.");
            Console.ReadLine();
        }
        catch (Exception e)
        {
            Console.WriteLine("Unexpected exception thrown: \n" + e.ToString());
            Console.ReadLine();
        }
    }

    // Determine whether OwnClipboard can be accessed.
    private static void DemandOwnClipboardAccess()
    {
        try
        {
            // Create a new UIPermission that allows access to OwnClipboard.
            UIPermission clipboardPermission = new UIPermission(UIPermissionClipboard.OwnClipboard);

            // Verify that callers higher in the stack have been granted
            // the permission.
            Console.WriteLine("Demanding OwnClipboard access.");
            clipboardPermission.Demand();
            Console.WriteLine("The demand was successful");
        }
        catch (SecurityException ex)
        {
            Console.WriteLine("A security exception was thrown while " +
                "demanding OwnClipboard access permission \n");
            Console.WriteLine(ex.Message);
        }
        catch (Exception ex)
        {
            Console.WriteLine("A fatal exception occurred:\n" +
                ex.ToString());
        }
    }

    // Determine whether OwnClipboard can be accessed.
    private static void DemandAllClipboardAccess()
    {
        try
        {
            // Create a new UIPermission that allows access to OwnClipboard.
            UIPermission clipboardPermission = new UIPermission(UIPermissionClipboard.AllClipboard);

            // Verify that callers higher in the stack have been granted
            // the permission.
            Console.WriteLine("Demanding AllClipboard access.");
            clipboardPermission.Demand();
            Console.WriteLine("The demand was successful");
        }
        catch (SecurityException ex)
        {
            Console.WriteLine("A security exception was thrown while " +
                "demanding AllClipboard access permission \n");
            Console.WriteLine(ex.Message);
        }
        catch (Exception ex)
        {
            Console.WriteLine("A fatal exception occurred:\n" +
                ex.ToString());
        }
    }
}

using namespace System;
using namespace System::Security;
using namespace System::Security::Permissions;
using namespace System::IO;

ref class UIPermissions
{
public:
   static void Main()
   {
      try
      {
         // Create a new UIPermission that allows access only to OwnClipboard.
         UIPermission^ clipboardPermission = gcnew UIPermission(
            UIPermissionClipboard::OwnClipboard );
         
         // Deny access to OwnClipboard.
         Console::WriteLine( L"Denying access to OwnClipboard" );
         clipboardPermission->Deny();
         
         // Demand access to files in the specified path.
         DemandOwnClipboardAccess();
         
         // Revert the Deny.
         Console::WriteLine( L"Reverting the Deny." );
         CodeAccessPermission::RevertDeny();
         DemandOwnClipboardAccess();

         // Grant access only to OwnClipboard.
         Console::WriteLine( L"Granting permission only for OwnClipboard access." );
         clipboardPermission->PermitOnly();
         DemandAllClipboardAccess();
         
         // Revert the PermitOnly with a call to RevertPermitOnly.
         Console::WriteLine( L"Reverting the PermitOnly." );
         CodeAccessPermission::RevertPermitOnly();
         DemandAllClipboardAccess();

         // Permit access only to OwnClipboard.
         clipboardPermission->PermitOnly();
         DemandAllClipboardAccess();
         
         // Revert the PermitOnly with a call to RevertAll.
         Console::WriteLine( L"Reverting the PermitOnly using RevertAll." );
         CodeAccessPermission::RevertAll();
         DemandAllClipboardAccess();

         Console::WriteLine( L"This sample completed successfully; "
             L"press Enter to exit." );
         Console::ReadLine();
      }
      catch ( Exception^ e ) 
      {
         Console::WriteLine( L"Unexpected exception thrown: \n{0}", e );
         Console::ReadLine();
      }
   }

private:
   // Determine whether OwnClipboard can be accessed.
   static void DemandOwnClipboardAccess()
   {
      try
      {
         // Create a new UIPermission that allows access to OwnClipboard.
         UIPermission^ clipboardPermission =
            gcnew UIPermission( UIPermissionClipboard::OwnClipboard );
         
         // Verify that callers higher in the stack have been granted
         // the permission.
         Console::WriteLine( L"Demanding OwnClipboard access." );
         clipboardPermission->Demand();
         Console::WriteLine( L"The demand was successful" );
      }
      catch ( SecurityException^ ex ) 
      {
         Console::WriteLine( L"A security exception was thrown while "
         L"demanding OwnClipboard access permission \n" );
         Console::WriteLine( ex->Message );
      }
      catch ( Exception^ ex ) 
      {
         Console::WriteLine( L"A fatal exception occurred:\n{0}", ex );
      }
   }

   // Determine whether OwnClipboard can be accessed.
   static void DemandAllClipboardAccess()
   {
      try
      {
         // Create a new UIPermission that allows access to OwnClipboard.
         UIPermission^ clipboardPermission =
            gcnew UIPermission( UIPermissionClipboard::AllClipboard );
         
         // Verify that callers higher in the stack have been granted
         // the permission.
         Console::WriteLine( L"Demanding AllClipboard access." );
         clipboardPermission->Demand();
         Console::WriteLine( L"The demand was successful" );
      }
      catch ( SecurityException^ ex ) 
      {
         Console::WriteLine( L"A security exception was thrown while "
         L"demanding AllClipboard access permission \n" );
         Console::WriteLine( ex->Message );
      }
      catch ( Exception^ ex ) 
      {
         Console::WriteLine( L"A fatal exception occurred:\n{0}", ex );
      }
   }

};

int main()
{
   UIPermissions::Main();
}

平台

Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

CodeAccessPermission 类
CodeAccessPermission 成员
System.Security 命名空间