This documentation is archived and is not being maintained.

How to: Create Smart Tags With Custom Recognizers in Excel and .NET Framework 3.5

In Excel projects that target the .NET Framework 3.5, you can control how Excel recognizes smart tags in documents by deriving from the Microsoft.Office.Tools.Excel.SmartTag class and overriding the Recognize method.

To run a smart tag, end users must have smart tags enabled. For more information, see How to: Enable Smart Tags in Word and Excel.

Applies to: The information in this topic applies to document-level projects and application-level projects for Excel 2007. For more information, see Features Available by Office Application and Project Type.

To add a smart tag with a custom recognizer to an Excel workbook

  1. Create a new document-level or application-level project for Excel 2007. For more information, see How to: Create Office Projects in Visual Studio.

  2. Add a reference to the Microsoft.Office.Interop.SmartTag assembly (version from the .NET tab of the Add Reference dialog box.

  3. Add a class file to the project and create a class that inherits from Microsoft.Office.Tools.Excel.SmartTag.

  4. In the new class, create the actions for the smart tags. Actions are items that appear on the smart tags menu. Create actions by adding instances of the Action type to your class's Actions collection.

  5. Override the SmartTagBase.Recognize method to implement your own custom recognizing behavior.

    Your override of the Recognize method must call the Microsoft.Office.Tools.Excel.SmartTag.PersistTag method to make Excel recognize the smart tag.

  6. Create event handlers to respond to the Click event, and optionally the BeforeCaptionShow event, of the actions that you created.

  7. In the code file for the project workbook, add the smart tag instance to the VstoSmartTags property of the ThisWorkbook class (for a document-level project), or the VstoSmartTags property of the ThisAddIn class (for an application-level project).

The following code example shows how to create a custom smart tag in an Excel workbook. The example overrides the Recognize method to recognize the terms sales and organization. The Recognize method adds a key and value pair to the collection of keyed properties for the smart tag. The method then calls the PersistTag method to recognize the smart tag and save the new smart tag property.

To test the example, type the words sales and organization in different cells in the workbook, and then try the smart tag actions. One action displays the corresponding property value for the recognized term, and the other action displays the smart tag namespace and caption.

using System;
using System.Windows.Forms;
using Microsoft.Office.Tools.Excel;
using Microsoft.Office.Interop.SmartTag;

    public class CustomSmartTag : SmartTag {

        // Declare Actions for this SmartTag
        Microsoft.Office.Tools.Excel.Action Action1 =
            new Microsoft.Office.Tools.Excel.Action("Display property value");
        Microsoft.Office.Tools.Excel.Action Action2 =
            new Microsoft.Office.Tools.Excel.Action("Display smart tag details");

        public CustomSmartTag() : base(
            "Custom Smart Tag")
            this.Terms.AddRange(new string[] { 
                "sales", "organization" });
            Actions = new Microsoft.Office.Tools.Excel.Action[] { Action1, Action2 };
            Action1.Click +=
                new ActionClickEventHandler(Action1_Click);
            Action2.Click += 
                new ActionClickEventHandler(Action2_Click);

        protected override void Recognize(string text, 
            ISmartTagRecognizerSite site, ISmartTagTokenList tokenList)
            // Determine whether each smart tag term exists in 
            // the document text.
            foreach (string term in this.Terms)
                // Search the cell text for the first instance of 
                // the current smart tag term.
                int index = this.CellText.IndexOf(term, 0);

                if (index >= 0)
                    // Create a smart tag token and a property bag for the 
                    // recognized term.
                    ISmartTagProperties propertyBag = 

                    // Write a new property value.                 
                    string key = "Key1";
                    propertyBag.Write(key, DateTime.Now.ToString());

                    // Attach the smart tag to the term in the document

                    // This implementation only finds the first instance
                    // of a smart tag term in the cell. 

        // This action displays the property value for the term.
        private void Action1_Click(object sender, ActionEventArgs e)
            ISmartTagProperties propertyBag = e.Properties;
            string key = "Key1";
            MessageBox.Show("The corresponding value of " + key +
                " is: " + propertyBag.get_Read(key));

        // This action displays smart tag details.
        private void Action2_Click(object sender, ActionEventArgs e)
            MessageBox.Show("The current smart tag caption is '" + 
                this.Caption + "'. The current smart tag type is '" + 
                this.SmartTagType + "'.");

  • Add a reference in the project to Microsoft Smart Tags 2.0 Type Library from the COM tab of the Add Reference dialog box. Ensure that the Copy Local property of the reference is false. If it is true, the reference is not to the correct primary interop assembly and you must install the assembly from the Microsoft Office installation media. For more information, see How to: Install Office Primary Interop Assemblies.

  • Place the example code in a new class file named CustomSmartTag.

  • In C#, change the namespace to match the project name.

  • Add Imports (in Visual Basic) or using (in C#) statements for the Microsoft.Office.Tools.Excel and Microsoft.Office.Interop.SmartTag namespaces at the top of the class file.

  • Add the following code to the ThisWorkbook_Startup or ThisAddIn_Startup event handler in your project. This code adds the custom smart tag to the workbook.

    Me.VstoSmartTags.Add(New CustomSmartTag())

    this.VstoSmartTags.Add(new CustomSmartTag());

You must enable smart tags in Excel. By default, they are not enabled. For more information, see How to: Enable Smart Tags in Word and Excel.