To create a SOLIDWORKS .NET add-in that implements this interface:

1. Open a new project in Visual Studio using SOLIDWORKS template, Visual C# - SwCSharpAddin.
2. Add CNotification_A_Handler.cs with the following code to the add-in to handle user notifications:
   
   

   using System;

   using System.Collections.Generic;

   using System.Linq;

   using System.Text;

   using System.Runtime.InteropServices;

   using SolidWorks.Interop.sldworks;

   using SolidWorks.Interop.swpublished;

   using System.Diagnostics;
   

   namespace addin_name

   {

       public class CNotification_A_Handler : IUserNotificationHandler

       {

           // The add-in author needs to decide how the handler should react to user responses

           // In this example, pass the SOLIDWORKS application object and the target model into the handler's constructor for later use

           // Model can be null here since notifications can relate to the application, rather than the document

           private ISldWorks iswApp;

           private ModelDoc2 iswModelDoc;

           public CNotification_A_Handler(ISldWorks swApp, ModelDoc2 swModelDoc)

           {

               iswApp = swApp;

               iswModelDoc = swModelDoc;

           }

           public void OnTimeout()

           {

               Debug.Print("CNotification_A_Handler::OnTimeout");

               // To Do: Implement desired response

           }

           public void OnUserClose()

           {

               Debug.Print("CNotification_A_Handler::OnUserClose");

               // To Do: Implement desired response

           }

           public void OnUserResponseA(bool DoNotShowAgain)

           {

               Debug.Print(String.Format("CNotification_A_Handler::OnUserResponseA, Don't Show Again? == {0}", DoNotShowAgain));

               // To Do: Implement desired response

           }

           public void OnUserResponseB(bool DoNotShowAgain)

           {

               Debug.Print(String.Format("CNotification_A_Handler::OnUserResponseB, Don't Show Again? == {0}", DoNotShowAgain));

               // To Do: Implement desired response

           }

       }

   }

3. Add a ShowNotification() function to the UI Callbacks region in SwAddin.cs to declare and define a user notification and create the user notification handler:
   

   public class SwAddin : ISwAddin
   {
       ...
       private const String NotifyID_A = "MyAddInName+Notification_A";
       private IUserNotificationDefinition NotifyDefn_A;
   
   

   
   
   
       void ShowNotification()
       {
           // This unique user notification is triggered from the command bar.
           // Have we already defined this user notification in this session? If so, reuse it.
           if (NotifyDefn_A == null)
           {
               // Create a new notification definition
               NotifyDefn_A = swApp.DefineUserNotification(NotifyID_A) As IUserNotificationDefinition;
               // Configure the notification definition
               NotifyDefn_A.Severity = (int) swUserNotificationSeverity_e.swUserNotificationSeverity_Warning;
               NotifyDefn_A.Title = "Notification from my add-in";
               NotifyDefn_A.Message = "Something important happened that you should know about.";
               NotifyDefn_A.ResponseAType = (int) swUserNotificationResponseType_e.swUserNotificationResponseType_Button;
               NotifyDefn_A.ResponseAText = "OK";
               // ResponseBType & ResponseBText have default values: swUserNotificationResponseType_None & ""
               // IncludeDoNotShowAgain has default value: VARIANT_TRUE
           }
   

           ModelDoc2 swModelDoc = swApp.ActiveDoc;
   

   
   
           // Create a handler for this instance of the user notification;
           // In this example, the handler will go out of scope here
           // SOLIDWORKS will retain its pointer to the handler object until the notification has been dismissed and the response callback has been called.
           CNotification_A_Handler myHandler =  new CNotification_A_Handler(swApp, swModelDoc);       
    
           // Show the user notification for the application
   

           String strTarget = "";
   

             
           swShowNotificationResult_e notifyResult;
   
   
           if (swModelDoc != null)
   
   
           {
   
   
               strTarget = "IModelDocExtension";
   
   
               notifyResult = (swShowNotificationResult_e)swModelDoc.Extension.ShowUserNotification(NotifyDefn_A, myHandler);
   
   
           }
   
   
           else
   
   
           {
   
   
               strTarget = "ISldWorks";
   
   
               notifyResult = (swShowNotificationResult_e)swApp.ShowUserNotification(NotifyDefn_A, myHandler);
   
   
           }
   
   
   
   
           
           switch (notifyResult)
           {
               case swShowNotificationResult_e.swShowNotificationResult_Shown:
                   // The *modeless* notification has been shown
                   break;
               case swShowNotificationResult_e.swShowNotificationResult_DontShowAgain:
                   // The notification was not shown because 'Don't show again' was previously checked
                   break;
               case swShowNotificationResult_e.swShowNotificationResult_FailedInvalidDefinition:
                   // The notification could not be displayed due to an invalid definition (e.g. empty title/description) 
                   break;
               case swShowNotificationResult_e.swShowNotificationResult_FailedInvalidHandler:
                   // The notification was not displayed because the Handler argument was NULL or did not support the expected interface
                   break;
               default:
                   // Unknown error
                   break;
           }
       }
   
   }
   

4. Modify the UI Methods region in SwAddin.cs to add a command item to the add-in's toolbar:
   
   cmdIndex0 = cmdGroup.AddCommandItem2("Show Notification", -1, "Show User Notification", "Show User Notification", 0, "ShowNotification", "", mainItemID1, menuToolbarOption);