Calling DLL functions

You use the parts within the External Functions category to access or call functions written in either C or COBOL. The C or COBOL features must be loaded into VA Smalltalk before you can use these parts.

In addition to providing the steps for calling DLL functions, the following information is also available:

•	Overview of calling external functions

Steps for calling DLL functions

1.	From the External Functions category , add either a C External Function part or a COBOL External Function part , depending upon whether the DLL was written in C or COBOL.

If you choose the C External Function part, you must have access to a header (.H) file defining the data types used by the function. If you choose the COBOL External Function part, you must have access to a copy library file defining the record formats used by the function.

2.	Double-click on the part to open its Settings window and use the DLL tab to identify the specifications for the DLL that contains the external function.

3.	Build the parameter list for the external function by doing one of the following:

a.	On the Record tab, manually build the parameter list by parsing the C-header file or the COBOL copy library file for the external function.

b.	On the Prototypes tab, do the following:

1.	Automatically build the parameter list by parsing the C-header file or the COBOL copy library file for the external function.

2.	Select the external function you want to call from the list.

4.	Select OK on the Settings window.

5.	Connect to the C or COBOL external function you want to call.