1. The basic concept of ActiveX
ActiveX control can be regarded as a very small server application, it cannot run independently, it must be embedded in a container program and run together with the container. This container includes WEB pages, application forms and so on. . .
The suffix of ActiveX controls is OCX or DLL. Generally, the files packaged into cab or exe in the form of coexistence of OCX and dynamic library are placed on the server. After the client downloads, run and install the cab or exe to decompress it into a coexistence file of OCX and dynamic library, and then register the ocx file.
ActiveX controls are based on the com standard, a set of technologies that enable software components to interact in a network environment. It has nothing to do with a specific programming language. As a technology developed for Internet applications, ActiveX is widely used in all aspects of WEB servers and clients. At the same time, ActiveX technology is also used to easily create common desktop applications, and ActiveX generally has an interface.
ActiveX control, simply put, it is a plug-in of IE browser, such as IE's Flash player is an ActiveX control. ActiveX has obvious security problems, because it is actually a program. If you install an ActiveX control, then this control has the right to do many things on your computer, such as secretly monitoring your web browsing records, in the background Install malicious programs, generate pop-up windows on your computer from time to time, and even steal your account password, etc. Because of this, the IE kernel browser sometimes prompts you not to load these controls;
Fortunately, ActiveX controls only run in Windows, and only limited to Microsoft's own software, such as IE browser, Office, etc.; if you use Chrome, Firefox and other browsers, you don't need to worry about the possible harm caused by ActiveX controls, because The plug-ins used by these browsers belong to a different category of plug-ins than ActiveX controls;
2. Three concepts: ActiveX, OLE and COM
From the perspective of time, OLE appeared first, followed by COM and ActiveX; from the perspective of architecture, OLE and ActiveX are built on COM, so COM is the foundation; from the perspective of names, OLE and ActiveX are Two brand names, while COM is a purely technical term, which is why people hear more about ActiveX and OLE. COM was born in response to the needs of OLE, so although COM is the basis of OLE, OLE came before COM. The basic starting point of COM is to allow one piece of software to provide services to another piece of software through a common mechanism. The core technology of ActiveX is COM. The biggest difference between ActiveX and OLE is that OLE is aimed at the integration between application software and files on the desktop, while ActiveX mainly provides further network applications and user interaction. COM objects can be written in any language such as C++, Java , and VB, and can be implemented in the form of DLLs or executable files that work as different processes. A browser that uses COM objects doesn't need to care what language the object is written in, or whether it's executed in a DLL or another process. From the browser side, there is no difference. Such a general processing trick is very useful.
Reference URL: https://blog.csdn.net/Alisa_xf/article/details/73558603