The AutoCAD .NET API enables you to manipulate AutoCAD and drawing files programmatically with the assemblies or libraries that are exposed. With these objects exposed, they can be accessed by many different programming languages and environments.

There are several advantages to implementing a .NET API for AutoCAD:

• Programmatic access to AutoCAD drawings is opened up to more programming environments. Before the .NET API, developers were limited to ActiveX^® Automation and languages that supported COM, AutoLISP®, and C++ with ObjectARX.
• Integrating with other Windows® based applications, such as Microsoft Excel and Word, is made dramatically easier by using an application’s native .NET API or exposed ActiveX/COM library.
• The .NET Framework is designed for both 32-bit and 64-bit operating systems. Visual Basic for Applications was only designed for 32-bit operating systems.
• Allows access to advanced programming interfaces with a lower learning curve than those for more traditional programming languages such as C++.

Objects are the main building blocks of the AutoCAD .NET API. Each exposed object represents a precise part of AutoCAD, and they are grouped into different assemblies and namespaces. There are many different types of objects in the AutoCAD .NET API. For example:

• Graphical objects such as lines, arcs, text, and dimensions
• Style settings such as text and dimension styles
• Organizational structures such as layers, groups, and blocks
• The drawing displays such as view and viewport
• The drawing and AutoCAD application

For information on some of the files which make up the AutoCAD .NET API, see Components of the AutoCAD .NET API.