Visual InterDev 1.0 Design-Time Control SDK provides the following interfaces and methods for making an ActiveX control into a design-time control. The primary reason to create a design-time control is for generating run-time text.
The method you use for generating text depends on the language you are using. For Visual Basic projects, use the GetRunTimeText method of the IProvideRuntimeText interface. For Visual C++ and other types of projects, use the SaveRuntimeState method of the IActiveDesigner interface. The output is handled differently in Visual Basic because it doesn't process text streams the same way as other languages.