Step 2: Choose a Visual or Nonvisual Run-Time Object

Whether the run-time object is visual or not, it must have a window and it must implement a default event interface.

Visual Run-Time Object

You have a couple of choices in implementing a visual run-time object:

• Use the Designer Wizard to generate a designer.
  
  
• Inherit from CComDesignerBase in order to have access to the registry keys such as MiscStatus bits or TypelibID. You will need to modify your .rgs files accordingly.

Because CComDesignerToolbox provides design-time features only, a run-time instance should not inherit from it.

Nonvisual Run-Time Object

To implement a run-time object that does not have a visual user interface, use CComDesignerInvisAtRun, which provides dynamic registration features and provides an IOleObject interface for object siting.

A nonvisual run-time object also requires the interfaces listed below. You can use the ATL Object Wizard to generate an ATL Simple object with these interfaces. A nonvisual run-time object need not derive from CComControl.

The following example shows an object that is derived from CComDesignerInvisAtRun:

class ATL_NO_VTABLE CShapesInstCtl : 
   public CComObjectRootEx<CComSingleThreadModel>,
   public CComCoClass<CShapesInstCtl, &CLSID_ShapesInstCtl>,
   public IProvideClassInfo2Impl<&CLSID_ShapesInstCtl,
       &DIID_DShapesEvents, &LIBID_SHAPESINSTLib>,
   public IDispatchImpl<IShapesInstCtl,
      &IID_IShapesInstCtl, &LIBID_SHAPESINSTLib>,
   public CProxyDShapesEvents<CShapesInstCtl>,
   public IConnectionPointContainerImpl<CShapesInstCtl>
   public CComDesignerInvisAtRun<CShapesInstCtl,RegEntryArray>,
{
   . . .
}