ArcGIS Engine Developer Guide

C++ APPLICATION PROGRAMMING INTERFACE
For the sake of simplicity the code snippets given
don’t always check HRESULTs, although as a
developer you should always do so.
RECOMMENDED FUNCTION USAGE
The C++ API provides its own implementation of some functions. Below are the
names and descriptions of the general API functions and examples of their use.
For additional information on the Motif- and GTK-specific functions, see the
sections ‘Motif ArcGIS control programming’ and ‘GTK ArcGIS control programming’,
respectively.
General API functions (described below)
• AoInitialize
• AoUninitialize
• AoExit
• AoCreateObject
• AoAllocBSTR
• AoFreeBSTR
• AoToolbarAddCommand
• AoToolbarAddTool
Motif-specific API functions
• MwCtlAppMainLoop
• MwCtlGetInterface
GTK-specific API functions
• gtk_axctl_new
• gtk_axctl_get_interface
• gtk_axctl_initialize_message_queue
AoInitialize, AoUninitialize, and AoExit
• AoInitialize—used where CoInitialize would be used in COM programming.
extern "C" HRESULT AoInitialize(LPVOID pvReserved);
This function initializes ArcGIS Engine. The initialization must be done prior
to ArcObjects being used and in addition to the use of the IAoInitialize interface,
which handles licensing for the application.
• AoUninitialize—used where CoUninitialize would be used in COM programming.
extern "C" void AoUninitialize(void);
This function uninitializes ArcGIS Engine.
• AoExit—used where exit would be used in non-ArcObjects code, as well as
where return would be used in main.
extern "C" VOID AoExit (int number);
AoExit must be called before an application is exited. This allows portability
to supported operating systems that require AoExit to correctly clean up
various ArcGIS Engine elements.
224 • ArcGIS Engine Developer Guide