COM Interop

The Component Object Model (COM) allows an object to expose its functionality to other components and to host applications. Most of today's software includes COM objects. Although .NET assemblies are the best choice for new applications, you may at times need to employ COM objects. This section covers some of the issues associated with creating and using COM objects with Visual Basic.

In This Section

• Introduction to COM Interop
  Provides an overview of COM interoperability.

• How to: Reference COM Objects from Visual Basic
  Covers how to add references to COM objects that have type libraries.

• How to: Work with ActiveX Controls
  Demonstrates how to use existing ActiveX controls to add features to the Visual Studio Toolbox.

• Walkthrough: Calling Windows APIs
  Steps you through the process of calling the APIs that are part of the Windows operating system.

• How to: Call Windows APIs (Visual Basic)
  Demonstrates how to define and call the MessageBox function in User32.dll.

• Walkthrough: Creating COM Objects with Visual Basic
  Steps you through the process of creating COM objects with and without the COM class template.

• Troubleshooting Interoperability
  Covers some of the problems you may encounter when using COM.

• COM Interoperability in .NET Framework Applications
  Provides an overview of how to use COM objects and .NET Framework objects in the same application.

Related Sections

• Walkthrough: Implementing Inheritance with COM Objects
  Demonstrates how to use classes in COM objects as the basis for inheritance in Visual Basic.

• Interoperating with Unmanaged Code
  Describes interoperability services provided by the common language runtime.

• Exposing COM Components to the .NET Framework
  Describes the process of calling COM types through COM interop.

• Exposing .NET Framework Components to COM
  Describes the preparation and use of managed types from COM.

• Applying Interop Attributes
  Covers attributes you can use when working with unmanaged code.