Home » Tip Bank » Visual Basic

Language: Visual Basic, C++
Expertise: Intermediate

May 28, 1999

Some C++ programmers develop Win32 API DLLs that can used from Visual Basic programs. Use the __stdcall prefix with functions exported from the C++ DLL that you want to access from VB 5.0. For example, the code in a simple Win32 DLL exporting GetMyComputerName using .def would be:

 
.Def File contents::

LIBRARY  <library-name>
DESCRIPTION "Some description"
EXPORTS
     GetMyComputerName        @1

.CPP file contents::
BOOL __stdcall GetMyComputerName(LPSTR szComputerName, LPSTR szErrorMsg)
{
...
....
}

This function could be used in VB after declaring the following:

 
Declare Function GetMyComputerName Lib "<dll filename>" (ByVal strComputerName
As String, ByVal strErrorMsg As String) As Long