DnsPermission.Union(IPermission) Method

Definition

Namespace:

System.Net

Assembly:

System.Security.Permissions.dll

Creates a permission instance that is the union of the current permission instance and the specified permission instance.

public:
 override System::Security::IPermission ^ Union(System::Security::IPermission ^ target);

public override System.Security.IPermission Union (System.Security.IPermission target);

override this.Union : System.Security.IPermission -> System.Security.IPermission

Public Overrides Function Union (target As IPermission) As IPermission

Parameters

target

IPermission

The DnsPermission instance to combine with the current instance.

Returns

IPermission

A DnsPermission instance that represents the union of the current DnsPermission instance with the specified DnsPermission instance. If target is null, this method returns a copy of the current instance. If the current instance or target is unrestricted, this method returns a DnsPermission instance that is unrestricted; otherwise, it returns a DnsPermission instance that is restricted.

Exceptions

ArgumentException

target is neither a DnsPermission nor null.

Examples

The following example creates a permission instance that is the union of the current permission instance and the specified permission instance.

private:
   void MyUnion()
   {
      // Create a DnsPermission instance that is the union of the current DnsPermission
      // instance and the specified DnsPermission instance.
      DnsPermission^ permission = dynamic_cast<DnsPermission^>(dnsPermission1->Union( dnsPermission2 ));
      // Print the attributes and the values of the union instance of DnsPermission.
      PrintKeysAndValues( permission->ToXml()->Attributes );
   }

public:
   void useDns()
   {
      // Create a DnsPermission instance.
      dnsPermission1 = gcnew DnsPermission( PermissionState::Unrestricted );
      dnsPermission2 = gcnew DnsPermission( PermissionState::None );
      // Check for permission.
      dnsPermission1->Demand();
      dnsPermission2->Demand();
      Console::WriteLine( "Attributes and Values of first DnsPermission instance :" );
      PrintKeysAndValues( dnsPermission1->ToXml()->Attributes );
      Console::WriteLine( "Attributes and Values of second DnsPermission instance :" );
      PrintKeysAndValues( dnsPermission2->ToXml()->Attributes );
      Console::WriteLine( "Union of both instances : " );
      MyUnion();
      Console::WriteLine( "Intersection of both instances : " );
      MyIntersection();
   }

private:
   void PrintKeysAndValues( Hashtable^ myList )
   {
      // Get the enumerator that can iterate through the hash tabble.
      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();
   }

private void MyUnion()
{
   // Create a DnsPermission instance that is the union of the current DnsPermission
   // instance and the specified DnsPermission instance.
   DnsPermission permission = (DnsPermission)dnsPermission1.Union(dnsPermission2);
   // Print the attributes and the values of the union instance of DnsPermission.
   PrintKeysAndValues(permission.ToXml().Attributes);
}
public void useDns() {
   // Create a DnsPermission instance.
   dnsPermission1 = new DnsPermission(PermissionState.Unrestricted);
   dnsPermission2 = new DnsPermission(PermissionState.None);
   // Check for permission.
   dnsPermission1.Demand();
   dnsPermission2.Demand();
   Console.WriteLine("Attributes and Values of first DnsPermission instance :");
   PrintKeysAndValues(dnsPermission1.ToXml().Attributes);
   Console.WriteLine("Attributes and Values of second DnsPermission instance :");
   PrintKeysAndValues(dnsPermission2.ToXml().Attributes);
   Console.WriteLine("Union of both instances : ");
   MyUnion();
   Console.WriteLine("Intersection of both instances : ");
   MyIntersection();
}

private void PrintKeysAndValues(Hashtable myList) {
   // Get the enumerator that can iterate through the hash tabble.
   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();
}

Private Sub MyUnion()
    ' Create a DnsPermission instance which is the union of the current DnsPermission instance and the specified DnsPermission instance.
    Dim permission As DnsPermission = CType(dnsPermission1.Union(dnsPermission2), DnsPermission)
    ' Print the attributes and values of the union instance of DnsPermission.
    PrintKeysAndValues(permission.ToXml().Attributes)
End Sub
Public Sub useDns()
    ' Create a DnsPermission instance.
    dnsPermission1 = New DnsPermission(PermissionState.Unrestricted)
    dnsPermission2 = New DnsPermission(PermissionState.None)
    ' Check for permission.
    dnsPermission1.Demand()
    dnsPermission2.Demand()
    Console.WriteLine("Attributes and Values of first DnsPermission instance :")
    PrintKeysAndValues(dnsPermission1.ToXml().Attributes)
    Console.WriteLine("Attributes and Values of second DnsPermission instance :")
    PrintKeysAndValues(dnsPermission2.ToXml().Attributes)
    Console.WriteLine("Union of both instances : ")
    MyUnion()
    Console.WriteLine("Intersection of both instances : ")
    MyIntersection()
End Sub

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

Remarks

The Union method returns a DnsPermission instance that allows the access defined by either the current DnsPermission instance or the specified DnsPermission instance. Any demand that passes either permission passes their union.