Debugging (ActiveX Control)
Developer Control Bar
The Developer Control Bar monitors all ActiveX Control method calls and errors. Options are available on the system menu of the Developer Control Bar to switch on and off the method calls, triggers and error output.
Note also that the Developer Control Bar has an Always on Top option that forces it to always appear on top of other windows.
API Errors
Any errors incurred by an API method can be checked in a Visual Basic program (as well as being output in the Developer Control Bar).
All API subroutines, as opposed to functions that return a value, return an error code. This error code will have the same value as the system variable ExecError&. The value of _ExecError& can be checked after function calls in order to check that they succeeded. The GetErrorString method can be used to get a textual version of an error number.
The SISCONST.VB/SISCONST.H file contains a list of the errors that can occur when using the ActiveX Control.