Walkthrough: Creating Your First Application-Level Add-in for Project

Applies to

The information in this topic applies only to the specified Visual Studio Tools for Office projects and versions of Microsoft Office.

Project type

  • Application-level projects

Microsoft Office version

  • Project 2007

  • Project 2003

For more information, see Features Available by Application and Project Type.

This walkthrough shows you how to create an application-level add-in for Microsoft Office Project. The features that you create in this kind of solution are available to the application itself, regardless of which projects are open. For more information, see Office Solutions Development Overview.

This walkthrough illustrates the following tasks:

  • Creating a Project add-in project for Project 2003 or Project 2007.

  • Writing code that uses the object model of Project to add a task to a new project.

  • Building and running the project to test it.

  • Cleaning up the completed project so that the add-in no longer runs automatically on your development computer.


Your computer might show different names or locations for some of the Visual Studio user interface elements in the following instructions. The Visual Studio edition that you have and the settings that you use determine these elements. For more information, see Visual Studio Settings.


You need the following components to complete this walkthrough:

  • Visual Studio Tools for Office (an optional component of Visual Studio 2008 Professional and Visual Studio Team System).

  • Project 2003 or Project 2007.

By default, Visual Studio Tools for Office is installed with the listed versions of Visual Studio. To check whether it is installed on your computer, see Installing Visual Studio Tools for Office.

Creating the Project

To create a new project in Visual Studio

  1. Start Visual Studio.

  2. On the File menu, point to New, and then click Project.

  3. In the Project Types pane, expand Visual C# or Visual Basic, and then expand Office.

  4. Select the 2007 folder if you are developing an add-in for Project 2007, or select the 2003 folder if you are developing an add-in for Project 2003.


    If you are developing an add-in for a particular version of Microsoft Project, that version must be installed on your development computer.

  5. In the Templates pane, select Project 2007 Add-in or Project 2003 Add-in.

  6. In the Name box, type FirstProjectAddIn.

  7. Click OK.

    Visual Studio creates the FirstProjectAddIn project and opens the ThisAddIn code file in the editor.

Writing Code that Adds a New Task to a Project

Next, add code to the ThisAddIn code file. The new code uses the object model of Project to add a new task to a project. By default, the ThisAddIn code file contains the following generated code:

  • A partial definition of the ThisAddIn class. This class provides an entry point for your code and provides access to the object model of Project. For more information, see AddIn Host Item. The remainder of the ThisAddIn class is defined in a hidden code file that you should not modify.

  • The ThisAddIn_Startup and ThisAddIn_Shutdown event handlers. These event handlers are called when Project loads and unloads your add-in. Use these event handlers to initialize your add-in when it is loaded, and to clean up resources used by your add-in when it is unloaded. For more information, see Visual Studio Tools for Office Project Events.

To add a task to a new project

  • In the ThisAddIn code file, add the following code to the ThisAddIn class. This code defines an event handler for the NewProject event of the Microsoft.Office.Interop.MSProject.Application class.

    When the user creates a new project, this event handler adds a task to the project.

    Private Sub Application_NewProject(ByVal pj As Microsoft.Office.Interop.MSProject.Project) Handles Application.NewProject
        Dim newTask As MSProject.Task
        newTask = pj.Tasks.Add _
        ("This text was added by using code")
        newTask.Start = DateTime.Now
        newTask.Duration = "3"
        newTask.ResourceNames = "Rob Caron, Kelly Krout" 
    End Sub
    void Application_NewProject(Microsoft.Office.Interop.MSProject.Project pj)
        MSProject.Task newTask = pj.Tasks.Add
            ("This text was added by using code", missing);
        newTask.Start = DateTime.Now;
        newTask.Duration = "3";
        newTask.ResourceNames = "Rob Caron, Kelly Krout";

To modify the project, this code example use the following objects:

  • The Application field of the ThisAddIn class. The Application field returns an Microsoft.Office.Interop.MSProject.Application object, which represents the current instance of Project.

  • The pj parameter of the event handler for the NewProject event. The pj parameter is a Microsoft.Office.Interop.MSProject.Project object, which represents the project. For more information, see Project Solutions.

  1. If you are using C#, add the following code to the ThisAddIn_Startup event handler. This code connects the Application_Newproject event handler with the NewProject event.

    this.Application.NewProject += new Microsoft.Office.Interop.MSProject._EProjectApp2_NewProjectEventHandler(Application_NewProject);

Testing the Project

When you build and run the project, verify that the new task appears in the resulting new project.

To test the project

  1. Press F5 to build and run your project. Microsoft Project starts and automatically opens a new blank project.

    When you build the project, the code is compiled into an assembly that is included in the build output folder for the project. Visual Studio also creates a set of registry entries that enable Project to discover and load the add-in, and it configures the security settings on the development computer to enable the add-in to run. For more information, see Office Solution Build Process Overview.

  2. Verify that a new task is added to the blank project.

  3. Verify that the following text appears in the Task Name field of the task.

    This text was added by using code.

  4. Close Microsoft Project.

Cleaning up the Project

When you finish developing a project, remove the add-in assembly, registry entries, and security settings from your development computer. Otherwise, the add-in will run every time you open Microsoft Project on the development computer.

To clean up your project

  • In Visual Studio, on the Build menu, click Clean Solution.

Next Steps

Now that you have created a basic application-level add-in for Project, you can learn more about how to develop add-ins from these topics:

See Also


Programming Application-Level Add-Ins

Project Solutions

Visual Studio Tools for Office Project Templates Overview


2003 Microsoft Office Add-in Project Templates

2007 Microsoft Office Add-in Project Templates

Other Resources

Building and Debugging Office Solutions

Deploying Office Solutions

Change History




July 2008

Added topic.

Information enhancement.