[V8i] [C# .NET] Using Undo function in IPrimitive Event

I would like to write a tool which is similar to place smart line which has endless points to click unless you click rest or close element. In place smart line tool, you can use Ctrl + Z and then continue with your existing location. However, when you are in IPrimitive Event, using Ctrl + Z will directly interrupt it and the IPrimitive Event will no longer workable. Any examples / measures to solve this? Moreover, in CONNECT Edition, I see this problem is still existing. 

Parents Reply Children
No Data