DnsPermission.IsSubsetOf(IPermission) 方法

定义

命名空间:

System.Net

程序集:

System.Security.Permissions.dll

程序集:

System.dll

确定当前权限实例是否是指定权限实例的子集。

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

参数

target

IPermission

第二个需测试子集关系的 DnsPermission 实例。

返回

Boolean

如果当前实例是不受限制的，并且 target 或者为 false 或者是不受限制的，则为 null；否则，为 true。

例外

ArgumentException

target 既不是 DnsPermission，也不是 null。

示例

以下示例使用该方法 IsSubsetOf 来确定当前权限实例是否是指定权限实例的子集。

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

注解

如果当前实例指定由指定实例完全包含的一组操作，则当前DnsPermissionDnsPermission实例是指定DnsPermissionDnsPermission实例的子集。

IsSubsetOf如果该方法返回true，则当前DnsPermission实例不允许再访问 DNS 服务器，而不是指定的DnsPermission实例。