Hi Wei,

>VFP allows to use drag&drop to add controls listed in the toolbar to a grid. Can I drag&drop a control in my classlib to a grid? Thanks in advance.

Depends your Controls' BaseClass.
In VFP's toolbar you need select your Classlib (in the side the "arrow" button have another button with some "book", called "View Class", click it and choice "Add" and in Dialog Box type your Classlib). Your classes will be in ToolBox. Thus, Drag & Drop they.
Obs.: I think that some controls can't Drag & Drop to grid.
Was it this that you wanted? I hope this help you.