External Component

Windows DLL

In EPL, you can directly call windows dynamic link library, meanwhile also means you can call Windows API by call a dll function. You must declare a Dll function first before you use it, you should specify basic attribute of a dll function, such as function name, parameter, and return value type. Basically, almost all Windows API functions and other DLL functions can be called by EPL. After you declare a dll function, just use it as use a common function.

The following shows you some examples that to declare a same Windows API by C++ & EPL.

 

MoveWindow

 

In C++ originally

BOOL MoveWindow (HWND hWnd, int X, int Y, int nWidth, int nHeight, BOOL bRepaint);

 

In EPL

CreateThread

 

In C++ originally

HANDLE CreateThread(LPSECURITY_ATTRIBUTES lpThreadAttributes,

DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,

LPVOID lpParameter, DWORD dwCreationFlags,

LPDWORD lpThreadId);

 

In EPL

Windows OCX Control

You can use ActiveX control (OCX) and Type Library in EPL to extend EPL and your application. EPL also provides a very useful tool that packs ActiveX Control/TypeLib to EPL Library, the packed EPL Library is just store programming elements information, the actual implementation will still be implemented in corresponding ActiveX Controls or TypeLib, the tools enable you to rename a method, property, event name and you can also add description to them

To add an ActiveX control to your program, just select it from OCX/TypeLib list, and convert it to compatible library file (*.npk), finally load npk file for using.

Notice: you must packs to convert ActiveX control or TypeLib before using it.

Choose an OCX or Type Library to Convert

Select Preconverted NPK

Use OCX in EPL

Windows COM

EPL provides Windows COM (The Component Object Model) supporting. Using COM you can do things such as Office Automation.

To operate a COM object, you can use “Object” data type in kernel library, and use “Variant” data type to store COM Variant