ActiveX objects 

What is an ActiveX Object?

  • An ActiveX object is an instance of an ActiveX control or component that can be used in a program.
  • These objects expose methods, properties, and events that can be automated — meaning other programs can control or interact with them dynamically.
  • They typically support Automation (formerly called OLE Automation), which allows applications like Microsoft Excel, Word, or Internet Explorer to be programmatically controlled through these objects.

Key Features of ActiveX Objects-

  • Automation Support: They expose interfaces that can be controlled by scripting languages like VBScript, JavaScript, or languages supporting COM (like C++, VB, C#).
  • Reusability: Once created, these objects can be reused in different applications without rewriting code.
  • Interoperability: They allow different software components to communicate, even if written in different languages.
  • Embedding: ActiveX controls can be embedded in web pages (mostly Internet Explorer) or desktop applications to add functionality like media players, file viewers, or form controls.

Typical Use Cases-

  • Web Browsers: Embedding multimedia players, interactive forms, or ActiveX-based controls in Internet Explorer.
  • Office Automation: Controlling Microsoft Office apps (Excel, Word) via scripts or other programs to automate repetitive tasks.
  • Custom Desktop Apps: Adding reusable UI components or background services that expose programmable interfaces.

How Do You Use an ActiveX Object?

In scripting (for example, VBScript or JavaScript in Windows):

Set excelApp = CreateObject("Excel.Application")
excelApp.Visible = True
excelApp.Workbooks.Add
excelApp.Cells(1,1).Value = "Hello ActiveX!"

This creates an Excel application object, makes it visible, adds a workbook, and writes text to the first cell.

Security Concerns-

  • ActiveX controls have full access to the Windows system, so malicious or poorly designed controls can harm your system.
  • Modern browsers have largely moved away from ActiveX due to these risks and compatibility issues.
  • ActiveX is mostly legacy technology now but still used in some enterprise or legacy applications.

 

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