DnsPermission.Intersect(IPermission) Method

Definition

Namespace:

System.Net

Assembly:

System.Security.Permissions.dll

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

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

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

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

Public Overrides Function Intersect (target As IPermission) As IPermission

Parameters

target

IPermission

The DnsPermission instance to intersect with the current instance.

Returns

IPermission

A DnsPermission instance that represents the intersection of the current DnsPermission instance with the specified DnsPermission instance, or null if the intersection is empty. If both the current instance and target are unrestricted, this method returns a new DnsPermission instance that is unrestricted; otherwise, it returns null.

Exceptions

ArgumentException

target is neither a DnsPermission nor null.

Examples

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

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();
   }

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

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

Private Sub MyIntersection()
    ' Create a DnsPermission instance that is the intersection of the current
    ' DnsPermission instance and the specified DnsPermission instance.
    Dim permission As DnsPermission = CType(dnsPermission1.Intersect(dnsPermission2), DnsPermission)
    ' Print the attributes and values of the intersection instance of DnsPermission.
    PrintKeysAndValues(permission.ToXml().Attributes)
End Sub

Remarks

The Intersect method returns a DnsPermission instance that allows the access defined by both the current DnsPermission instance and the specified DnsPermission instance. Any demand must pass both permissions to pass their intersection.