. NET component Programming (8) Component Documentdesigner (document Designer)

Each component not only has component Designer, but also component Documentdesigner, but what is the difference between these two Designer? I use the more popular FA to make the difference, Component Designer refers to the UI designer that is displayed when a Component is dragged onto a form or page container (Figure 1); Component Documentdesigner refers to the component itself root document designer (Figure 2).

For example, there are two component, whose name is BaseClass1 and Class1, and Class1 inherits from BaseClass1, we designed BASECLASS1 for Documentdesigner, The design items are not visible in the BaseClass1 document designer and are visible in Class1.