HOW TO: Create an Office XP Smart Tag DLL by Using Visual C# .NET

Smart Tags are a technology that was introduced with Office XP that provides Office users more interactivity with the content of their Office documents. A Smart Tag is an element of text in an Office document that is recognized as having custom actions associated with it. An example of one of these special elements of text might be an e-mail name that is typed into a Word document or an Excel workbook. If the e-mail name is recognized as a Smart Tag, the user is presented with one or more actions to perform on the selected text. Possible actions associated with an e-mail name are to look up additional contact information, or to send a new e-mail message to that contact.

You can extend the capabilities of Office XP by developing your own Smart Tag Recognizer/Action DLL for use in Office documents. This article describes how to build a Smart Tag DLL by using Visual C# .NET and discusses what registry settings are required for Office XP to identify and use your Smart Tag DLL.

NOTE: Excel 2002 and Word 2002 are the only Office XP programs that support Smart Tags. However, the information presented in this article can be applied to Smart Tag development for any program that adopts the Smart Tag technology.

Smart Tag Interfaces

A Smart Tag DLL is an object that implements two special interfaces: ISmartTagRecognizer and ISmartTagAction. The ISmartTagRecognizer interface is responsible for recognizing text that is typed into a document as a Smart Tag. The ISmartTagAction interface is responsible for performing actions on a particular Smart Tag string at the user's request. It is not required that these interfaces be implemented in the same DLL. You can have a recognizer DLL, and then one or more action DLLs that extend a single Smart Tag type for different actions.

Documentation for these interfaces, and the type library that defines them, is provided in the Smart Tag Software Development Kit (SDK). If you have not already done so, install the Smart Tag SDK before you continue with the steps to create the sample Smart Tag. You can obtain the Smart Tag SDK from the Microsoft Office XP Developer (MOD) CD-ROM, or you can download it. To download the Smart Tag SDK, visit the following Microsoft Web site:

Step-by-Step Instructions to Build a Smart Tag DLL

 The following steps create a simple Smart Tag DLL that recognizes the Microsoft Network (MSN) Instant Messenger contacts and gives the user the ability to send e-mail or instant messages to a recognized contact. You must have Instant Messenger 4.5 to use this sample.

Create the Resource Libraries and Install Them in the Global Assembly Cache

1. On the Start menu, point to Programs, click Microsoft Visual Studio .NET, click Visual Studio .NET Tools, and then click Visual Studio .NET Command Prompt. Change to the root directory of drive C.
2. Generate strong named key pairs by issuing the following commands:

   sn -k SmartTagLib.snk
   sn -k Messenger.snk
   sn -k SmartTagSample.snk
   					

3. From the command prompt, change the directory to the location that contains the Smart Tag SDK type library. The default location for this directory is C:\Program Files\Common Files\Microsoft Shared\Smart Tag.
4. Issue the following command to generate the strong named wrapper DLL from the type library:NOTE: The following command is case-sensitive. If you do not follow the case that is presented below, you may have to change the sample code so that it will work.

   tlbimp mstag.tlb /keyfile:c:\SmartTagLib.snk /out:c:\SmartTagLib.dll
   					

5. Issue the following command to install this DLL into the global assembly cache:

   gacutil /i c:\SmartTagLib.dll
   					

6. From the command prompt, change the directory to the installation location for MSN Instant Messenger. The default location for this directory is C:\Program Files\Messenger.
7. Issue the following command to generate the strong named wrapper DLL from the type library:NOTE: The following command is case-sensitive. If you do not follow the case that is presented below, you may have to change the sample code so that it will work.

   tlbimp msmsgs.exe\3 /keyfile:c:\Messenger.snk /out:c:\Messenger.dll 

8. Issue the following command to install this DLL into the global assembly cache:

   gacutil /i c:\Messenger.dll

Create the Smart Tag DLL

1. Start Microsoft Visual Studio .NET. On the File menu, click New, and then click Project. Under Project types click Visual C# Projects, and then select Class Library. Name the project SmartTagSample. Class1 is created by default.
2. Add references to the MSN Instant Messenger Library and the Smart Tag SDK library that you just created. To do this, follow these steps:
   1. On the Project menu, click Add Reference.
   2. Click Browse. In the Select Component dialog box, select C:\SmartTagLib.dll, and then click Open.
   3. Click Browse. In the Select Component dialog box, select C:\Messenger.dll, and then click Open.
   4. Click OK in the Add References dialog box to accept your selections.
3. In the Project Properties window, rename Class1.cs to Recognizer.cs.
4. Replace the code in the code window for Recognizer.cs with the following:

   using System;
   using System.Diagnostics;
   
   namespace SmartTagSample
   {
   	public class Recognizer : SmartTagLib.ISmartTagRecognizer
   	{
   		String[] Contacts;
   
   		public Recognizer()
   		{
   			int i;
   			Messenger.MessengerClass oMessenger = new Messenger.MessengerClass();
   			Messenger.IMessengerContacts oUsers;
   
   			oUsers = (Messenger.IMessengerContacts) oMessenger.MyContacts;
   			Contacts = new String[oUsers.Count];
   			i = 0;
   
   			foreach (Messenger.IMessengerContact oUser in oUsers)
   			{
   				Contacts.SetValue(oUser.FriendlyName.ToLower(),i);
   				i++;
   			}
   		}
   
   		public string ProgId
   		{
   			get 
   			{
   				Debug.WriteLine("Recognizer::ProgID");
   				// Return the ProgID of the Recognizer interface.
   				return "SmartTagSample.Recognizer";
   			}
   
   		}
   
   		public int SmartTagCount
   		{
   			get
   			{
   				Debug.WriteLine("Recognizer::SmartTagCount");
   				// Return the number of Smart Tags you support.
   				return 1;
   			}
   		}
   
   
   		public System.String get_Desc ( System.Int32 LocaleID )
   		{
   			Debug.WriteLine("Recognizer::Desc");
   			// Return a long description of your recognizer.
   			return 
                           "Microsoft Messenger recognizes your Instant Messenger Contacts";
   		}
   
   		public System.String get_Name ( System.Int32 LocaleID )
   		{
   			Debug.WriteLine("Recognizer::Name");
   			// Return a short title about your recognizer.
   			return "Microsoft Messenger Contacts Visual C# .NET Recognizer";
   		}
   
   		public System.String get_SmartTagDownloadURL ( System.Int32 SmartTagID )
   		{
   			Debug.WriteLine("Recognizer::SmartTagDownloadURL");
   			// Return the URL that is embedded in documents.
   			return null;
   		}
   
   		public System.String get_SmartTagName ( System.Int32 SmartTagID )
   		{
   			Debug.WriteLine("Recognizer::SmartTagName");
   			// This method is called the same number of times as you
   			// return in SmartTagCount. This method sets a unique name
   			// for the Smart Tag.
   			return "microsoft/messenger#contacts";
   		}
   
   		public void Recognize ( System.String Text , SmartTagLib.IF_TYPE DataType , 
                System.Int32 LocaleID , SmartTagLib.ISmartTagRecognizerSite RecognizerSite )
   		{
   			
   			Debug.WriteLine("Recognizer::Recognize");
   			// The Recognize method is called and passed a text value.
   			// You should recognize strings in the text and set up the actions.
   			int i;
   			int startpos;
   			int strlen;
   			SmartTagLib.ISmartTagProperties propbag;
   
   			// Convert the text to lowercase.
   			Text = Text.ToLower();
   			// Loop through all contacts.
   			for (i = 0; i < Contacts.GetUpperBound(0); i++) 
   			{
   				// Look for a contact name in the text.
   				startpos = Text.IndexOf(Contacts[i]) + 1;
   				// Find the length of the contact name.
   				strlen = Contacts[i].Length;
   				// Look for all occurrences of contacts in the string.
   				while (startpos > 0) 
   				{
   					// Create a new property bag.
   					propbag = RecognizerSite.GetNewPropertyBag();
   					// Commit the Smart Tag to the property bag.
   					RecognizerSite.CommitSmartTag("microsoft/ 
   					messenger#contacts", startpos, strlen, propbag);
   					// Continue looking for contacts in the string.
   					startpos = Text.IndexOf(Contacts[i],startpos + 
                                           strlen) + 1;
   				}
   			} 
   		}
   	}
   }
   					

5. On the Project menu, select Add Class. Under Templates, select Class, and then name the class Action.cs. Click Open to create the new class.
6. Replace the code in the code window for Action.cs with the following:

   using System;
   using System.Diagnostics;
   
   namespace SmartTagSample
   {
   	public class Action: SmartTagLib.ISmartTagAction
   	{
   
   		// Property implementation.
   		public string ProgId
   		{
   			get 
   			{
   				Debug.WriteLine("Action::ProgID");
   				// Return the ProgID of the Action interface.
   				return "SmartTagSample.Action";
   			}
   
   		}
   
   		public int SmartTagCount
   		{
   			get
   			{
   				Debug.WriteLine("Action::SmartTagCount");
   				// Return the number of smart tags that
   				// this action supports.
   				return 1;
   			}
   		}
   
   
   		public System.String get_Desc ( System.Int32 LocaleID )
   		{
   			Debug.WriteLine("Action::Desc");
   			// Return a long description describing the action.
   			return 
                           "Provides actions for the Messenger Smart Tag";
   		}
   
   		public System.String get_Name ( System.Int32 LocaleID )
   		{
   			Debug.WriteLine("Action::Name");
   			// Return a short name describing the action.
   			return "Messenger Smart Tag";
   		}
   
   		public System.String get_SmartTagCaption 
                           ( System.Int32 SmartTagID , System.Int32 LocaleID )
   		{
   			Debug.WriteLine("Action::SmartTagCaption");
   			// This caption appears on the menu
   			// for the smart tag.
   			return "Messenger Smart Tag";
   		}
   
   		public System.String get_SmartTagName ( System.Int32 SmartTagID )
   		{
   			Debug.WriteLine("Action::SmartTagName");
   			// This method is called the same number of 
   			// times as you return in SmartTagCount.
   			// This method sets a unique name
   			// for the smart tag.
   			return "microsoft/messenger#contacts";
   		}
   
   		public System.String get_VerbCaptionFromID ( System.Int32 VerbID , 
                   System.String ApplicationName , System.Int32 LocaleID )
   		{
   			Debug.WriteLine("Action::VerbCaptionFromID");
   			// Get a caption for each verb.
   			// This caption appears
   			// on the Smart Tag menu.
   			switch(VerbID) 
   			{
   				case 1:
   					return 
                                           "Send this contact an Instant Message";
   				case 2:
   					return 
                                           "Send e-mail to this contact";
   				default:
   					return null;
   			}
   		}
   
   		public System.Int32 get_VerbCount 
                                       ( System.String SmartTagName )
   		{
   			Debug.WriteLine("Action::VerbCount");
   			// Return the number of verbs you support.
   			if
                            (SmartTagName.Equals("microsoft/messenger#contacts")) 
   			{
   				return 2;
   			}
   			return 0;
   		}
   
   		public System.Int32 get_VerbID ( System.String SmartTagName , 
                                                    System.Int32 VerbIndex )
   		{
   			Debug.WriteLine("Action::VerbID");
   			// Return a unique ID for each verb you support.
   			return VerbIndex;
   		}
   
   		public System.String get_VerbNameFromID ( System.Int32 VerbID )
   		{
   			// Return a string name for each verb.
   			switch(VerbID) 
   			{
   				case 1:
   					return "SendInstantMessage";
   				case 2:
   					return "SendEmail";
   				default:
   					return null;
   			}
   		}
   
   		public void InvokeVerb ( System.Int32 VerbID , System.String 
                   ApplicationName , System.Object Target , 
                   SmartTagLib.ISmartTagProperties Properties , System.String Text , 
                   System.String Xml )
   		{
   			Debug.WriteLine("Action::InvokeVerb");
   			// This method is called when a user invokes a verb
   			// from the Smart Tag menu.
   			Messenger.MessengerClass oMessenger = 
                                  new Messenger.MessengerClass();
   			Messenger.IMessengerContacts oUsers;
   
   			oUsers = (Messenger.IMessengerContacts)
                                     oMessenger.MyContacts;
   			foreach (Messenger.IMessengerContact oUser in oUsers)
   			{
   				if (String.Compare(oUser.FriendlyName,Text,true) == 0) 
   				{
   					switch(VerbID) 
   					{
   						case 1:
   							// The user wants to display the
   							// Instant Message box to send
   							//  the contact a message.
   							oMessenger.InstantMessage(oUser);
   							break;
   						case 2:
   							// Shell the "mailto" protocol to 
   							// start the user's mail program
   							//  and create a new message.
   							System.Diagnostics.Process.Start
                                                          ("mailto:" + oUser.SigninName);
   							break;
   					}
   				}
   			}
   		}
   	}
   }
   					

7. Open the Assemblyinfo.cs file.
8. Replace the line that reads

   [assembly: AssemblyKeyFile("")]
   					

   with:

   [assembly: AssemblyKeyFile("C:\\SmartTagSample.snk")]
   					

9. From Project Properties, select Build. Change the value of Register for COM Interop to True, and then click OK.
10. On the Build menu, click Build Solution to create the DLL.
11. From a Visual Studio .NET command prompt, change the directory to the bin\Debug directory for your project.
12. For this DLL to work correctly, you must install it into the global assembly cache. Issue the following command to install the DLL:

    gacutil /i SmartTagSample.dll
    					

Register the Smart Tag DLL for Use with Office

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
Before you can use any Smart Tag DLL, it must be registered on the system. Typical COM registration is completed for you when you compile the project, distribute the DLL with the Package and Deployment Wizard, or call Regsvr32.exe with the DLL name. You must create additional registry entries that are not part of typical COM registration so that Office applications can identify the DLL as a Smart Tag DLL. To do this, follow these steps:

1. From a command line, start Regedit.exe.
2. Locate the following key in the registry:
   HKEY_CURRENT_USER\Software\Microsoft\Office\Common\Smart Tag\Actions
3. Add a new subkey named SmartTagSample.Action.
4. Locate the following key in the registry:
   HKEY_CURRENT_USER\Software\Microsoft\Office\Common\Smart Tag\Recognizers
5. Add a new subkey named SmartTagSample.Recognize.
6. Close Registry Editor.

Steps to Test the Smart Tag DLL

Smart Tags obey the same security model as macros. If the security settings of the application are set to High, the Smart Tag DLL does not load unless Trust all installed add-ins and templates is selected. If the security settings are set to Medium and Trust all installed add-ins and templates is not selected, the user is prompted to enable or disable each add-in. Because the InprocServer32 key for the .NET assembly references the Mscoree.dll file instead of the DLL that you build, a dialog box prompts you to enable or disable macros for Mscoree.dll.

To test the custom Smart Tag Recognizer/Action DLL in Word, follow these steps:

1. Start Instant Messenger, and log on.
   
   NOTE: The sample Smart Tag requires that you log on to Instant Messenger; if you are not logged on to Instant Messenger, the custom DLL loads but does not recognize any contacts.
2. Start Word 2002. On the Tools menu, point to Macro, and then click Security. Set the macro security to Medium, and then click OK. If the macro security setting was previously set to High, restart Word.
3. Type the friendly name of a contact in a new document (for example, John Smith), and then press ENTER. A faint line appears under the friendly name to indicate that it is recognized as a Smart Tag. Move the pointer over the friendly name, and the Smart Tag Action button appears.
4. Click the Smart Tag button, and then select one of the custom action items from the drop-down menu. You can send an e-mail or instant message to the contact from your new document.

You can use similar steps to test the Smart Tag DLL in Excel 2002.

Troubleshooting

If you have problems getting your custom Smart Tags to work, first verify that the custom Smart Tag DLL is being loaded. In Word or Excel, on the Tools menu, click Auto Correct Options, click the Smart Tag tab, and verify that Label Text with Smart Tags is selected and that your Smart Tag DLL is listed and selected. If your Smart Tag is not listed, it may not be properly registered.

If the execution of the custom recognizer or action class is the source of the problem, you can debug a Smart Tag DLL as you would any Visual C# .NET DLL. From Project Properties, click Configuration Properties and then click Debugging. Select Start Application and specify the path to Winword.exe or Excel.exe. Set Debug Mode to Program, and then click OK. Set a breakpoint in the constructor for the class item that you want to debug. When Excel or Word starts and loads the Smart Tag, your code breaks at the breakpoint and you can step through the code for debugging.

Your Smart Tag DLL should trap and handle any run-time errors. If an error is raised in your code and the error is not handled, Office immediately unloads the DLL and clears the item so that it is not loaded again. This behavior is the same as the way Office treats COM Add-Ins, and can give you the impression that Office is not loading the DLL when it is in fact doing so, but was forced to unload it because of an unhandled run-time error.

For additional information about using CLSIDs to register the Smart Tag DLL instead of ProgIDs, click the article number below to view the article in the Microsoft Knowledge Base: For more information, visit the following Microsoft Web site: