About Using ActiveX Automation with the Microsoft .NET Framework (ActiveX)

AutoCAD automation objects can be accessed from projects created with Microsoft® Visual Studio®.

To fully access AutoCAD automation objects from Microsoft Visual Studio® .NET, create references to the following files:

• The AutoCAD 2015 type library, acax20enu.tlb, located at C:\Program Files\Common Files\Autodesk Shared.
• The AutoCAD/ObjectDBX Common 20.0 type library, axdb20enu.tlb, located at C:\Program Files\Common Files\Autodesk Shared.

These references will make available the following primary interop assemblies:

• Autodesk.AutoCAD.Interop.dll (for AutoCAD-specific types and Autodesk)
• AutoCAD.Interop.Common.dll (for types shared by ObjectDBX™ host applications)

The interop assemblies are located in the global assembly cache; they map automation objects to .NET counterparts.

After you reference the type libraries, you can declare AutoCAD-based variables in Microsoft Visual Studio .NET, as in the following examples:

Dim objAcad As Autodesk.AutoCAD.Interop.AcadApplication
Dim objLine As Autodesk.AutoCAD.Interop.Common.AcadLine

You can load a .NET application using the NETLOAD command in AutoCAD.

Additional information about using a .NET application with AutoCAD is available from the Developer Center section of the Autodesk website.