DnsPermission::IsSubsetOf Method (IPermission^)


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

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

virtual bool IsSubsetOf(
	IPermission^ target
) override


Type: System.Security::IPermission^

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

Return Value

Type: System::Boolean

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

Exception Condition

target is neither a DnsPermission nor null.

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.

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

   void useDns()
      // Create a DnsPermission instance.
      permission = gcnew DnsPermission( PermissionState::Unrestricted );
      DnsPermission^ dnsPermission1 = gcnew DnsPermission( PermissionState::None );
      // Check for permission.
      // 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 );

   void Subset( DnsPermission^ Permission1 )
      if ( permission->IsSubsetOf( Permission1 ) )
         Console::WriteLine( "Current 'DnsPermission' instance is a subset of specified 'DnsPermission' instance." );
         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 );

.NET Framework
Available since 1.1
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