Build the sample. The plugin (VBSample12.dll or CSSample12.dll) and the associated .tbp file are copied to the AutoCAD Map 3D Client bin directory.
Start AutoCAD Map 3D and open any workspace. A new toolbar button with the Sample 12 - Toolbar Button caption is displayed in a document-level toolbar in the AutoCAD Map 3D task pane.
If you click the button, the event handler is triggered.