Advanced PowerBuilder

Limits of a C++ User Object

C++ user objects can add power and flexibility to your applications, but remember that you do need prior knowledge of how to program in C++, which, it has to be said, has a longer learning curve than PowerScript. There are also a few limitations which you should bear in mind:

	Since a C++ user object is a non-visual user object, you can't use it to directly link any graphical (i.e. visual) C++ based custom controls with your PowerBuilder application.
	When you're linking controls with third-party DLLs, you have to refer to the documentation provided with the DLL to determine what classes and methods are declared, how it responds and its limitations in general. You would need the complete documentation of all the classes and functions embedded within the DLL to be able to use it effectively. So when you're shopping around for a third-party DLL or class library, check that the vendor provides good technical documentation and support.
	You can only write user events for the limited number of events that occur to the user object as a whole. These user events include: Constructor Destructor DragDrop DragEnter DragLeave DragWithin RButtonDown

In addition to these events, you can write custom user events for the user object as a whole.

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