ActiveX Control

ActiveX Control

ActiveX is a set of technology from Microsoft that enables us to make the interactive user interface. ActiveX technology has a set of components or control that can be embedded into another application & webpage. These controls can be programmed for getting active responses.

ActiveX control is controlled using three things –

Classification of ActiveX controls:

1.     Properties:

Properties are the attributes of the control that can be modified by the container application.

2.     Methods:

Methods are the function that can be called by container application to make these function available to another application, one interface is used which is known as IDispatch.

3.     Events:

Events are the message that can be sent from the control to the container application.

i.                    Stock Events:

Trigger mouse & keyboard events handling.

ii.                  Custom Events:

Trigger specific function event handling.

ActiveX Control Vs Ordinary Windows Controls:

ActiveX Control	Ordinary Windows Control
It can be embedded in application.	It cannot be embedded in application.
The important features of ActiveX control are properties & methods.	Ordinary windows control can be controlled by the message handler.
ActiveX controls can be embedded into webpage.	It cannot be embedded into webpage.
ActiveX control can be written using MFC, C#, C++, AIL	It can written as simple in win32 application or written in C.
It supports COM & OLE technologies.	It do not support any of both neither COM nor OLE.
They normally created in the .OCX.	The ordinary window control gets created in the .exe file.
It is easy to build some complex application such as window media player, Internet explorer.	Ordinary windows control can be used for building simple user interface based application.

Creating ActiveX Controls:

ActiveX is set of technology from Microsoft. It is used to provide better GUI facilities.

Installing ActiveX Controls:

ActiveX controls can be used when it is register in windows registry. There is a windows utility “Regsvr32”, using which the control can be registered.

Steps for installing ActiveX Control –

(Consider an ActiveX control we have named “ActiveCDemo.OCX”)

                                i.            Go to command prompt (cmd), locate the directory in which the “.OCX” file of your ActiveX control is present.

                              ii.            Type the command “C:\ActiveXDemo\debug\regsvr32 ActiveXDemo.OCX”

                            iii.            We will get following message on hitting Enter key –

       

ActiveX Control Container Programming:

ActiveX control container programming is a way by which how we used preinstalled and stored ActiveX control.

For installing the calendar we will apply following steps:

1.     Start VC++ 6.0, select MFC AppWizard (.exe) option, Give the project name and click ok.

2.     Now select the dialog based radio button and click net button. Accept the default value and generate application code.

3.     Now install the calendar control on the control toolbox, select the project menu-> Add to project-> Components and control. Then click insert button to insert the control.

This control will be added into control toolbox. This calendar control provides many events or properties to handle mouse and keyboard events.

Note:

When we build the project using MFC AppWizard (.exe), it must be ensured that the support for ActiveX control option is checked. Then the AppWizard do the following things –

i.                    It insert following line in the InitInstance member function of the application class –

AfxEnableControlContainer();

ii.                  It insert the following line in the “Stdafx.h”file

#include<afxdisp.h>