Using ActiveX Methods in Reactor Callback Functions

The second detail appearing in the pseudo-code shows up near the end, at the step for redrawing the tiles. Here is the pseudo-code statement:

Redraw the tiles (force ActiveX drawing)

The parenthetical phrase says it all: force ActiveX drawing. Why is this required? Why can't the application use the object creation preference stored in the association sublist?

The answer is you cannot use the command function for entity creation within a reactor callback function. This has to do with some internal workings of AutoCAD. You need to force the tile drawing routine to use ActiveX. You will hear more about this issue later in this lesson.