automating-word-by-using-extended-objects.md

title	description	ms.date	ms.topic	dev_langs	helpviewer_keywords	author	ms.author	manager	ms.subservice
Automate Word by using extended objects	Learn how you can use host items and host controls in your solutions when you develop Word solutions in Visual Studio.	02/02/2017	conceptual	VB CSharp	Word [Office development in Visual Studio], automating extended objects [Office development in Visual Studio], Word automation [Office development in Visual Studio], Word host items [Office development in Visual Studio], Word automating Word controls [Office development in Visual Studio], Word host controls host controls, Word host controls [Office development in Visual Studio], Word Word [Office development in Visual Studio], host controls	John-Hart	johnhart	mijacobs	office-development

Automate Word by using extended objects

When you develop Word solutions in Visual Studio, you can use host items and host controls in your solutions. These are objects that extend certain commonly used objects in the Word object model (that is, the object model that is exposed by the primary interop assembly for Word), such as the xref:Microsoft.Office.Interop.Word.Document and xref:Microsoft.Office.Interop.Word.ContentControl objects. The extended objects behave like the Word objects they are based on, but they add additional events and data binding capabilities to the objects.

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Host items and host controls are available in both VSTO Add-ins and document-level customizations, although the context in which these can be used is different for each type of solution. For more information, see Host items and host controls overview.

Document host item

Word projects give you access to the xref:Microsoft.Office.Tools.Word.Document host item. The xref:Microsoft.Office.Tools.Word.Document host item acts as a container for other controls, including host controls and Windows Forms controls, and it maintains information about the controls on its surface. The xref:Microsoft.Office.Tools.Word.Document host item also provides most of the same members as the xref:Microsoft.Office.Interop.Word.Document class, which is the corresponding class in the object model of Word.

For more information, see Document host item.

Word host controls

There are several host controls for Word that help you create, organize, and automate documents. Most of their functionality involves importing, presenting, and protecting data. These host controls provide events and data-binding capabilities that their counterparts in the native Word object model do not have.

In document-level projects, you can add any host control to your document at design time, or you can add content controls and bookmark controls at run time. In VSTO Add-in projects, you can add content controls and bookmark controls to any open document at run time.

For more information about the host controls you can use in Word projects, see the following topics:

• Content controls

• Bookmark control

• XMLNode control

• XMLNodes control

Related content

• How to: Add content controls to Word documents
• How to: Add Bookmark controls to Word documents
• How to: Add XMLNode controls to Word documents
• How to: Add XMLNodes controls to Word documents
• Walkthrough: Create a template by using content controls
• Walkthrough: Bind content controls to custom XML parts
• Walkthrough: Create shortcut menus for bookmarks
• Word solutions
• Host items and host controls overview
• Programmatic limitations of host items and host controls
• Extend Word documents and Excel workbooks in VSTO Add-ins at run time