DnsPermission.FromXml-Methode

Stellt eine DnsPermission-Instanz aus einer XML-Codierung wieder her.

Namespace: System.Net
Assembly: System (in system.dll)

Syntax

'Declaration
Public Overrides Sub FromXml ( _
    securityElement As SecurityElement _
)
'Usage
Dim instance As DnsPermission
Dim securityElement As SecurityElement

instance.FromXml(securityElement)

public override void FromXml (
    SecurityElement securityElement
)

public:
virtual void FromXml (
    SecurityElement^ securityElement
) override

public void FromXml (
    SecurityElement securityElement
)

public override function FromXml (
    securityElement : SecurityElement
)

Parameter

• securityElement
  Die XML-Codierung, die zum Wiederherstellen der DnsPermission-Instanz verwendet werden soll.

Ausnahmen

Hinweise

Die FromXml-Methode rekonstruiert eine DnsPermission-Instanz aus einer XML-Codierung, die durch die SecurityElement-Klasse definiert ist.

Verwenden Sie die ToXml-Methode, um die DnsPermission-Instanz einschließlich der Zustandsinformationen in XML zu codieren.

Beispiel

Im folgenden Beispiel wird eine DnsPermission-Instanz aus einer XML-Codierung rekonstruiert.

Public Sub ConstructDnsPermission()
    Try
        ' Create a DnsPermission instance.
        Dim permission As New DnsPermission(PermissionState.None)
        ' Create a SecurityElement instance by calling the ToXml method on the
        ' DnsPermission instance and print its attributes, 
        ' which hold the  XML encoding of the DnsPermission instance.
        Console.WriteLine("Attributes and Values of 'DnsPermission' instance :")
        PrintKeysAndValues(permission.ToXml().Attributes)
        
        ' Create a SecurityElement instacnce .
        Dim securityElementObj As New SecurityElement("IPermission")
        ' Add attributes and values of the SecurityElement instance corresponding to
        ' teh permission instance.
        securityElementObj.AddAttribute("version", "1")
        securityElementObj.AddAttribute("Unrestricted", "true")
        securityElementObj.AddAttribute("class", "System.Net.DnsPermission")
        
        ' Reconstruct a DnsPermission instance from an XML encoding.
        Dim permission1 As New DnsPermission(PermissionState.None)
        permission1.FromXml(securityElementObj)
        
        ' Print the attributes and values of the constructed DnsPermission object.
        Console.WriteLine("After reconstruction Attributes and Values of new DnsPermission instance :")
        PrintKeysAndValues(permission1.ToXml().Attributes)
    Catch e As NullReferenceException
        Console.WriteLine("NullReferenceException caught!!!")
        Console.WriteLine(("Source : " + e.Source))
        Console.WriteLine(("Message : " + e.Message))
    Catch e As SecurityException
        Console.WriteLine("SecurityException caught!!!")
        Console.WriteLine(("Source : " + e.Source))
        Console.WriteLine(("Message : " + e.Message))
    Catch e As ArgumentNullException
        Console.WriteLine("ArgumentNullException caught!!!")
        Console.WriteLine(("Source : " + e.Source))
        Console.WriteLine(("Message : " + e.Message))
    Catch e As Exception
        Console.WriteLine("Exception caught!!!")
        Console.WriteLine(("Source : " + e.Source))
        Console.WriteLine(("Message : " + e.Message))
    End Try
End Sub 'ConstructDnsPermission


Private Sub PrintKeysAndValues(myList As Hashtable)
    ' Get the enumerator that can iterate through the hash table.
    Dim myEnumerator As IDictionaryEnumerator = myList.GetEnumerator()
    Console.WriteLine(ControlChars.Tab + "-KEY-" + ControlChars.Tab + "-VALUE-")
    While myEnumerator.MoveNext()
        Console.WriteLine(ControlChars.Tab + "{0}:" + ControlChars.Tab + "{1}", myEnumerator.Key, myEnumerator.Value)
    End While
    Console.WriteLine()
End Sub 'PrintKeysAndValues

public void ConstructDnsPermission() {
  try 
  {
    // Create a DnsPermission instance.
    DnsPermission permission = new DnsPermission(PermissionState.None);
    // Create a SecurityElement instance by calling the ToXml method on the 
    // DnsPermission instance.
    // Print its attributes, which hold the  XML encoding of the DnsPermission
    // instance.
    Console.WriteLine("Attributes and Values of 'DnsPermission' instance :");
    PrintKeysAndValues(permission.ToXml().Attributes);

    // Create a SecurityElement instance.
    SecurityElement securityElementObj = new SecurityElement("IPermission");
    // Add attributes and values of the SecurityElement instance corresponding to
    // the permission instance. 
    securityElementObj.AddAttribute("version", "1");
    securityElementObj.AddAttribute("Unrestricted", "true");
    securityElementObj.AddAttribute("class","System.Net.DnsPermission");
                     
    // Reconstruct a DnsPermission instance from an XML encoding.
      DnsPermission permission1 = new DnsPermission(PermissionState.None);
    permission1.FromXml(securityElementObj);

    // Print the attributes and values of the constructed DnsPermission object.
    Console.WriteLine("After reconstruction Attributes and Values of new DnsPermission instance :");
    PrintKeysAndValues(permission1.ToXml().Attributes);
  }
  catch(NullReferenceException e) 
  {
    Console.WriteLine("NullReferenceException caught!!!");
    Console.WriteLine("Source : " + e.Source);
    Console.WriteLine("Message : " + e.Message);
  }
  catch(SecurityException e) 
  {
    Console.WriteLine("SecurityException caught!!!");
    Console.WriteLine("Source : " + e.Source);
    Console.WriteLine("Message : " + e.Message);
  }
  catch(ArgumentNullException e) 
  {
    Console.WriteLine("ArgumentNullException caught!!!");
    Console.WriteLine("Source : " + e.Source);
    Console.WriteLine("Message : " + e.Message);
  }
  catch(Exception e)
  {
    Console.WriteLine("Exception caught!!!");
    Console.WriteLine("Source : " + e.Source);
    Console.WriteLine("Message : " + e.Message);
  }
}

private void PrintKeysAndValues(Hashtable myList) {
   // Get the enumerator that can iterate through the hash table.
   IDictionaryEnumerator myEnumerator = myList.GetEnumerator();
   Console.WriteLine("\t-KEY-\t-VALUE-");
   while (myEnumerator.MoveNext())
      Console.WriteLine("\t{0}:\t{1}", myEnumerator.Key, myEnumerator.Value);
      Console.WriteLine();
}

public:
   void ConstructDnsPermission()
   {
      try
      {
         // Create a DnsPermission instance.
         DnsPermission^ permission = gcnew DnsPermission( PermissionState::None );
         // Create a SecurityElement instance by calling the ToXml method on the
         // DnsPermission instance.
         // Print its attributes, which hold the  XML encoding of the DnsPermission
         // instance.
         Console::WriteLine( "Attributes and Values of 'DnsPermission' instance :" );
         PrintKeysAndValues( permission->ToXml()->Attributes );
         
         // Create a SecurityElement instance.
         SecurityElement^ securityElementObj = gcnew SecurityElement( "IPermission" );
         // Add attributes and values of the SecurityElement instance corresponding to
         // the permission instance.
         securityElementObj->AddAttribute( "version", "1" );
         securityElementObj->AddAttribute( "Unrestricted", "true" );
         securityElementObj->AddAttribute( "class", "System.Net.DnsPermission" );
         
         // Reconstruct a DnsPermission instance from an XML encoding.
         DnsPermission^ permission1 = gcnew DnsPermission( PermissionState::None );
         permission1->FromXml( securityElementObj );
         
         // Print the attributes and values of the constructed DnsPermission Object*.
         Console::WriteLine( "After reconstruction Attributes and Values of new DnsPermission instance :" );
         PrintKeysAndValues( permission1->ToXml()->Attributes );
      }
      catch ( NullReferenceException^ e ) 
      {
         Console::WriteLine( "NullReferenceException caught!!!" );
         Console::WriteLine( "Source : {0}", e->Source );
         Console::WriteLine( "Message : {0}", e->Message );
      }
      catch ( SecurityException^ e ) 
      {
         Console::WriteLine( "SecurityException caught!!!" );
         Console::WriteLine( "Source : {0}", e->Source );
         Console::WriteLine( "Message : {0}", e->Message );
      }
      catch ( ArgumentNullException^ e ) 
      {
         Console::WriteLine( "ArgumentNullException caught!!!" );
         Console::WriteLine( "Source : {0}", e->Source );
         Console::WriteLine( "Message : {0}", e->Message );
      }
      catch ( Exception^ e ) 
      {
         Console::WriteLine( "Exception caught!!!" );
         Console::WriteLine( "Source : {0}", e->Source );
         Console::WriteLine( "Message : {0}", e->Message );
      }
   }

private:
   void PrintKeysAndValues( Hashtable^ myList )
   {
      // Get the enumerator that can iterate through the hash table.
      IDictionaryEnumerator^ myEnumerator = myList->GetEnumerator();
      Console::WriteLine( "\t-KEY-\t-VALUE-" );
      while ( myEnumerator->MoveNext() )
      {
         Console::WriteLine( "\t {0}:\t {1}", myEnumerator->Key, myEnumerator->Value );
      }
      Console::WriteLine();
   }

public void ConstructDnsPermission()
{
    try {
        // Create a DnsPermission instance.
        DnsPermission permission = 
            new DnsPermission(PermissionState.None);

        // Create a SecurityElement instance by calling the ToXml 
        // method on the DnsPermission instance.
        // Print its attributes, which hold the  XML encoding of the 
        // DnsPermission instance.
        Console.WriteLine("Attributes and Values of 'DnsPermission' "
            + "instance :");
        PrintKeysAndValues(permission.ToXml().get_Attributes());

        // Create a SecurityElement instance.
        SecurityElement securityElementObj = 
            new SecurityElement("IPermission");

        // Add attributes and values of the SecurityElement instance 
        // corresponding to the permission instance. 
        securityElementObj.AddAttribute("version", "1");
        securityElementObj.AddAttribute("Unrestricted", "true");
        securityElementObj.AddAttribute("class", 
            "System.Net.DnsPermission");

        // Reconstruct a DnsPermission instance from an XML encoding.
        DnsPermission permission1 = 
            new DnsPermission(PermissionState.None);
        permission1.FromXml(securityElementObj);

        // Print the attributes and values of the constructed
        // DnsPermission object.
        Console.WriteLine("After reconstruction Attributes and Values "
            + "of new DnsPermission instance :");
        PrintKeysAndValues(permission1.ToXml().get_Attributes());
    }
    catch (NullReferenceException e) {
        Console.WriteLine("NullReferenceException caught!!!");
        Console.WriteLine("Source : " + e.get_Source());
        Console.WriteLine("Message : " + e.get_Message());
    }
    catch (SecurityException e) {
        Console.WriteLine("SecurityException caught!!!");
        Console.WriteLine("Source : " + e.get_Source());
        Console.WriteLine("Message : " + e.get_Message());
    }
    catch (ArgumentNullException e) {
        Console.WriteLine("ArgumentNullException caught!!!");
        Console.WriteLine("Source : " + e.get_Source());
        Console.WriteLine("Message : " + e.get_Message());
    }
    catch (System.Exception e) {
        Console.WriteLine("Exception caught!!!");
        Console.WriteLine("Source : " + e.get_Source());
        Console.WriteLine("Message : " + e.get_Message());
    }
} //ConstructDnsPermission

private void PrintKeysAndValues(Hashtable myList)
{
    // Get the enumerator that can iterate through the hash table.
    IDictionaryEnumerator myEnumerator = myList.GetEnumerator();
    Console.WriteLine("\t-KEY-\t-VALUE-");
    while (myEnumerator.MoveNext()) {
        Console.WriteLine("\t{0}:\t{1}", myEnumerator.get_Key(),
            myEnumerator.get_Value());
    }
    Console.WriteLine();
} //PrintKeysAndValues

Plattformen

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 unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

DnsPermission-Klasse
DnsPermission-Member
System.Net-Namespace
SecurityElement