Today I wrote two test programs.

Tested the two technical issues of COM component inheritance and connection points. You can refer to this example to understand some difficult problems of arcobject.

Create an API igeometry. The menu is as follows:

 

Add another vertex interface ipoint, as shown in the following figure:

 

Several changes. Start with mygis. IDL:

 

If you need a function, you can also copy it:

 

Modify the cpoint class. The modification method is to directly Delete the inherited igeometry interface. As follows:

 

 

After the above steps, the entire process is complete.

You can check the calling methods.

Ipointptr P (clsid_point );
Long L = 0;
P-> getvalue (& L );

Igeometryptr G = P;
G-> getvalue (& L );

Arcengine9.2 has a toolbar control that requires a mapcontrol object. The toolbar allows you to edit images. What is the internal mechanism of this editing? The toolbar does not accept the mouse information of the map control, but can handle the mouse event accordingly. After analysis, the toolbar controls use the COM connection point technology to receive map controls and mouse and keyboard information.