2.2. Interface Between Visual Basic and Windows API
Basically speaking, calling a Windows API function is very similar to calling a DLL function developed in C/C++, because the Windows API itself is a collection of DLLs and all functions in the Windows API DLLs are written in C language (not in C++).
2.2.1. Windows API Functions
The Windows API contains thousands of functions, subroutines, types, and system constants that you can use in Visual Basic applications. In order to access and use any Windows API function, you should first declare the prototype of that function in Visual Basic format, which defines a mapping between the variables and components in Visual Basic and C/C++.
The thousands of Windows API functions, subroutines, and constants, ...