Interoperating with Unmanaged Code 

The Microsoft .NET Framework promotes interaction with COM components, COM+ services, external type libraries, and many operating system services. Data types, method signatures, and error-handling mechanisms vary between managed and unmanaged object models. To simplify interoperation between .NET Framework components and unmanaged code and to ease the migration path, the common language runtime conceals from both clients and servers the differences in these object models.

Code executing under the control of the runtime is called managed code. Conversely, code that runs outside the runtime is called unmanaged code. COM components, ActiveX interfaces, and Win32 API functions are examples of unmanaged code.

In This Section

• Interoperating with Unmanaged Code How-to Topics
  Provides links to all How-to topics found in the conceptual documentation for interoperating with unmanaged code.

• Exposing COM Components to the .NET Framework
  Describes how to use COM components from .NET-based applications.

• Exposing .NET Framework Components to COM
  Describes how to use .NET-based components from COM applications.

• Consuming Unmanaged DLL Functions
  Describes how to call unmanaged DLL functions using platform invoke.

• Design Considerations for Interoperation
  Provides tips for writing integrated COM components.

• Interop Marshaling
  Describes marshaling for COM interop and platform invoke.

• How to: Map HRESULTs and Exceptions
  Describes the mapping between exceptions and HRESULTs.

• Interoperating Using Generic Types
  Describes the behavior of generic types when used in COM interop.

Related Sections

• Advanced Development Technologies
  Provides links to more information on sophisticated development tasks and techniques in the .NET Framework