DnsPermission.IsSubsetOf(IPermission) Method

Definition

Namespace:

System.Net

Assembly:

System.Security.Permissions.dll

Package:

System.Security.Permissions v9.0.0-rc.2.24473.5

Source:

DnsPermission.cs

Determines whether the current permission instance is a subset of the specified permission instance.

public:
 override bool IsSubsetOf(System::Security::IPermission ^ target);

public override bool IsSubsetOf (System.Security.IPermission target);

override this.IsSubsetOf : System.Security.IPermission -> bool

Public Overrides Function IsSubsetOf (target As IPermission) As Boolean

Parameters

target

IPermission

The second DnsPermission instance to be tested for the subset relationship.

Returns

Boolean

false if the current instance is unrestricted and target is either null or unrestricted; otherwise, true.

Exceptions

ArgumentException

target is neither a DnsPermission nor null.

Examples

The following example uses the IsSubsetOf method to determine whether the current permission instance is a subset of the specified permission instance.

public:
   void useDns()
   {
      // Create a DnsPermission instance.
      permission = gcnew DnsPermission( PermissionState::Unrestricted );
      DnsPermission^ dnsPermission1 = gcnew DnsPermission( PermissionState::None );
      // Check for permission.
      permission->Demand();
      dnsPermission1->Demand();
      // Print the attributes and values.
      Console::WriteLine( "Attributes and Values of 'DnsPermission' instance :" );
      PrintKeysAndValues( permission->ToXml()->Attributes );
      Console::WriteLine( "Attributes and Values of specified 'DnsPermission' instance :" );
      PrintKeysAndValues( dnsPermission1->ToXml()->Attributes );
      Subset( dnsPermission1 );
   }

private:
   void Subset( DnsPermission^ Permission1 )
   {
      if ( permission->IsSubsetOf( Permission1 ) )
      {
         Console::WriteLine( "Current 'DnsPermission' instance is a subset of specified 'DnsPermission' instance." );
      }
      else
      {
         Console::WriteLine( "Current 'DnsPermission' instance is not a subset of specified 'DnsPermission' instance." );
      }
   }

   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 useDns() {
   // Create a DnsPermission instance.
   permission = new DnsPermission(PermissionState.Unrestricted);
   DnsPermission dnsPermission1 = new DnsPermission(PermissionState.None);
   // Check for permission.
   permission.Demand();
   dnsPermission1.Demand();
   // Print the attributes and values.
   Console.WriteLine("Attributes and Values of 'DnsPermission' instance :");
   PrintKeysAndValues(permission.ToXml().Attributes);
   Console.WriteLine("Attributes and Values of specified 'DnsPermission' instance :");
   PrintKeysAndValues(dnsPermission1.ToXml().Attributes);
   Subset(dnsPermission1);
}

private void Subset(DnsPermission Permission1)
{
   if(permission.IsSubsetOf(Permission1))
      Console.WriteLine("Current 'DnsPermission' instance is a subset of specified 'DnsPermission' instance.");
   else
      Console.WriteLine("Current 'DnsPermission' instance is not a subset of specified 'DnsPermission' instance.");
}

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 Sub useDns()
    ' Create a DnsPermission instance.
    permission = New DnsPermission(PermissionState.Unrestricted)
    Dim dnsPermission1 As New DnsPermission(PermissionState.None)
    ' Check  for permission.
    permission.Demand()
    dnsPermission1.Demand()
    ' Print the attributes and values.
    Console.WriteLine("Attributes and Values of 'DnsPermission' instance :")
    PrintKeysAndValues(permission.ToXml().Attributes)
    Console.WriteLine("Attributes and Values of specified 'DnsPermission' instance :")
    PrintKeysAndValues(dnsPermission1.ToXml().Attributes)
    Subset(dnsPermission1)
End Sub


Private Sub Subset(Permission1 As DnsPermission)
    If permission.IsSubsetOf(Permission1) Then
        Console.WriteLine("Current 'DnsPermission' instance is a subset of specified 'DnsPermission' instance.")
    Else
        Console.WriteLine("Current 'DnsPermission' instance is not a subset of specified 'DnsPermission' instance.")
    End If
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 current DnsPermission instance is a subset of the specified DnsPermission instance if the current DnsPermission instance specifies a set of operations that is wholly contained by the specified DnsPermission instance.

If the IsSubsetOf method returns true, the current DnsPermission instance allows no more access to DNS servers than does the specified DnsPermission instance.