Overview of ActiveX technology (i.)

Definition of 1.1.ActiveX

ActiveX is a set of technologies proposed by Microsoft that uses COM (Componentobjectmodel, part object models) to enable software parts to interact in a networked environment. It has nothing to do with the 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 facilitate the creation of common desktop applications.

1.2.ActiveX of content

ActiveX includes both server-side technology and client technology. Its main contents are:

*activex Control (ActiveXcontrol), which is used to insert COM objects into a container (Container) that supports ActiveX, such as Web pages, MicrosoftWord.

*activex document (Activexdocument), for browsing compound documents (non-HTML documents) in WebBrowser or other ActiveX-enabled containers, such as MicrosoftWord documents, Microsoft Excel documents or user-defined documents, and so on.

*activex Script Description (activexscripting) for manipulating ActiveX control and Java programs from the client or server side, passing data, and coordinating operations between them.

*activex Server Framework (Activexserverframework) provides a range of functions for Web server application design and its encapsulation classes, such as server filters, HTML Data flow control, and so on.

* Built-in Java Virtual machines (javavirtualmachine) in InternetExplorer to enable Javaapplet to run on InternetExplorer and to communicate with ActiveX control through scripting language.

1.3.ActiveX vs. Java comparison

ActiveX provides a mechanism for extending any programming language, including Java, in which Java developers can use ActiveX technology, embed ActiveX controls directly, or bridge ActiveX technology, Integrate the multilingual program objects provided by other developers into Java. Compared to Java bytecode technology, ActiveX provides "code signing" (CodeSigning) technology to ensure its security.

1.4.InternetExplorer and Netscapenavigator

It goes without saying that Microsoft's InternetExplorer fully supports ActiveX. At the same time, Microsoft provides netscapenavigator plug-ins (Plug-In) so that navigator can also browse Web sites that contain ActiveX parts.

2.ActiveX Control and Internet

ActiveX control is an updated version of OLE control. Control is the primary element that establishes a programmable part (Component). ActiveX control can be used in all containers that support COM specifications, or as an Internet control embedded in a Web page. When a user accesses the page, the control is downloaded and automatically registered locally. Script Description Language (scripts) enables communication between controls and between the client and the server by setting properties, invoking methods (method), and activating events (event).

ActiveX control has fewer interfaces than previous OLE controls, and can have no windows. All ActiveX controls support the IUnknown interface.

At present, many third-party developers have developed a wide range of ActiveX controls. Over 1000 ActiveX controls on the Internet are available for users to download and use. In Windows ' System directory, there are many ActiveX controls provided by window. Microsoftvisualc++ (hereinafter referred to as VC) provides MFC (Microsoftfoundationclasses) control is ActiveX control.

Given the relatively low transmission rate of the current Internet, you must consider the following issues when designing ActiveX controls that run on the Internet:

* Control as small as possible;

* How to save the continuous storage data (persistdata);

* How to download and install on the Internet;

* Control how to register on the client;

3.ActiveX Documents and Internet

ActiveX documents provide an extension method for traditional embedded objects. ActiveX Document objects can contain multiple pages, appear throughout the customer area, and support the original menu functionality. Unlike previous embedded objects, the ActiveX Document object is no longer displayed as a shaded box, but is the entire frame (fullframe) and is always active.

MICROSOFTOFFICE97 provides microsoftofficebinder for building and browsing composite documents consisting of MicrosoftWord, MicrosoftExcel, or user-defined ActiveX documents. Each type of document can be edited directly.

An ActiveX document can be embedded as an object in a Web page and published on the web.

4.ActiveX Script Description Language

With VBScript or Microsoftjscript, you can add ActiveX controls to your Web page that can be used for interaction, put data preprocessing or validation processes on the client, and then pass the results to the Web server.

5.ActiveX Server Framework

Create an extended application on a Web server to dynamically generate Web pages. The ISAPI classes provided with MFC make it easy to build Web server-side extension applications.

6.visualc++5.0 's support for ActiveX

vc++5.0 (Enterprise Edition) provides a complete solution for Internet development, with the following contents:

* Develop ActiveX control and ActiveX documentation using MFC or ATL.

* Use ISAPI to design a Web server-side part.

* Use WinInet to develop applications that access files over the Internet.

* Use Asynchronousmonikers to generate applications that download data from the Internet.

* Use ACTIVEXSDK to develop other types of internet-based Win32 applications, including activexscriptinghost,microsoftwebconferencing.