Get started programming VSTO Add-ins

You can use VSTO Add-ins to automate Microsoft Office applications, extend features of the application, and customize the user interface (UI) of the application. For information about how VSTO Add-ins compare to other types of Office solutions you can create by using Visual Studio, see Office solutions development overview (VSTO).

Applies to: The information in this topic applies to VSTO Add-in projects. For more information, see Features available by Office application and project type.

Create VSTO Add-in projects

Create VSTO Add-in projects by using one of the VSTO Add-in project templates in the New Project dialog box. These templates include required assembly references and project files. Visual Studio provides VSTO Add-in project templates for most applications in Office.

For more information about how to create a VSTO Add-in project, see How to: Create Office projects in Visual Studio. For more information about the project templates, see Office project templates overview.

Develop VSTO Add-in projects

When you create a VSTO Add-in project, Visual Studio automatically creates a ThisAddIn.vb (in Visual Basic) or ThisAddIn.cs (in C#) code file. This file contains the ThisAddIn class, which provides the foundation for your VSTO Add-in. You can use members of this class to run code when the VSTO Add-in is loaded or unloaded, to access the object model of the host application, and to extend features of the application. For more information, see Program VSTO Add-Ins.

Automate applications by using the Object models

The object models of Microsoft Office applications expose many types that you can program against in a VSTO Add-in. You can use these types to automate the application. For example, you can programmatically create and send an e-mail message in Outlook, or you can open a document and add content in Word. For more information about how to access the object model of the host application in code, see Program VSTO Add-Ins.

For more information about the object models of specific Microsoft Office applications, see the following topics:

• Excel object model overview

• Word object model overview

• Outlook object model overview

• InfoPath solutions

• PowerPoint solutions

• Project solutions

• Visio object model overview

Customize the user interface of applications

There are several different ways to customize the UI of the host application by using a VSTO Add-in:

• For Excel and Word, you can add managed controls to documents. For more information, see Extend Word documents and Excel workbooks in VSTO Add-ins at run time.

• You can customize the Ribbon if the application supports it. For more information, see Ribbon overview.

• You can create a custom task pane if the application supports it. For more information, see Custom task panes.

• For Outlook, you can create a custom form region. For more information, see Create Outlook form regions.

• For all Microsoft Office applications, you can display Windows Forms in your VSTO Add-in.

  For more information about how to customize the UI of Microsoft Office applications, see Office UI customization.

Related content

• Walkthrough: Create your first VSTO Add-in for Excel
• Walkthrough: Create your first VSTO Add-In for Outlook
• Walkthrough: Create your first VSTO Add-in for PowerPoint
• Walkthrough: Create your first VSTO Add-in for Project
• Walkthrough: Create your first VSTO Add-in for Word
• Common tasks in Office programming
• How to: Create Office projects in Visual Studio
• Get started (Office development in Visual Studio)
• Write code in Office solutions
• Architecture of VSTO Add-ins
• Program VSTO Add-ins