The PostFilter method override

    protected override void PostFilterProperties(System.Collections.IDictionary properties)

    {

      base.PostFilterProperties (properties);

      //The properties that would cause the control to cease functioning

      //in the designer must be replaced with harmless copies.

      //EnableTimeout is replaced with the designers harmless one

      properties["EnableTimeout"]=TypeDescriptor.CreateProperty(

        typeof(AControlDesigner),

        (PropertyDescriptor)properties["EnableTimeout"],

        new Attribute[0]);

      //UsableTime is also replaced

      properties["UsableTime"]=TypeDescriptor.CreateProperty(

        typeof(AControlDesigner),

        (PropertyDescriptor)properties["UsableTime"],

        new Attribute[0]);

    }

    Protected Overrides Sub PostFilterProperties(ByVal properties As System.Collections.IDictionary)

      MyBase.PostFilterProperties(properties)

      'The properties that would cause the control to cease functioning

      'in the designer must be replaced with harmless copies.

      'EnableTimeout is replaced with the designers harmless one

      properties("EnableTimeout") = TypeDescriptor.CreateProperty(GetType(AControlDesigner), CType(properties("EnableTimeout"), PropertyDescriptor), New Attribute(-1) {})

      'UsableTime is also replaced

      properties("UsableTime") = TypeDescriptor.CreateProperty(GetType(AControlDesigner), CType(properties("UsableTime"), PropertyDescriptor), New Attribute(-1) {})

    End Sub 'PostFilterProperties