Issues after I add a command filter to textview

Question

I want to intercept key events in vs. I searched many articles for help, and this article inspired me. What I have done is:

1. create a new class and implement "IVsTextManagerEvents" interface to register every textview.

   public void OnRegisterView(IVsTextView pView)
   {
       CommandFilter filter = new CommandFilter();
       IOleCommandTarget nextCommandTarget;
       pView.AddCommandFilter(filter, out nextCommandTarget);
       filter.NextCommandTarget = nextCommandTarget;
   }
   

2. add new class "CommandFilter" which implement IOleCommandTarget , in which we can intercept olecommand from vs

   public class CommandFilter : IOleCommandTarget
   {    
   
       public IOleCommandTarget NextCommandTarget
       {
           get; 
           set;
       }
   
       public int QueryStatus(ref Guid pguidCmdGroup, uint cCmds, OLECMD[] prgCmds, IntPtr pCmdText)
       {
           NextCommandTarget.QueryStatus(ref pguidCmdGroup, cCmds, prgCmds, pCmdText);
           return VSConstants.S_OK;
       }
   
       public int Exec(ref Guid pguidCmdGroup, uint nCmdID, uint nCmdexecopt, IntPtr pvaIn, IntPtr pvaOut)
       {
           if (pguidCmdGroup == typeof(VSConstants.VSStd2KCmdID).GUID)
           {
               switch (nCmdID)
               {
                   case (uint)VSConstants.VSStd2KCmdID.RETURN:
                       MessageBox.Show("enter");
                       break;
               }
           }
   
           NextCommandTarget.Exec(pguidCmdGroup, nCmdID, nCmdexecopt, pvaIn, pvaOut);
   
           return VSConstants.S_OK;
       }
   }
   

3. we need to advise IVsTextManagerEvents in Initialize

   protected override void Initialize()
   {
       base.Initialize();
   
       IConnectionPointContainer textManager = (IConnectionPointContainer)GetService(typeof(SVsTextManager));
       Guid interfaceGuid = typeof(IVsTextManagerEvents).GUID;
       textManager.FindConnectionPoint(ref interfaceGuid, out tmConnectionPoint);
       tmConnectionPoint.Advise(new TextManagerEventSink(), out tmConnectionCookie);
   }
   

after above prepare, we can now intercept key events. you can see a message box after you stroke key "enter".

My question is, after I have done above

1. I can't save the document, that means when I stroked ctrl+S, nothing happened.
2. You can see obvious delay, when I key in words. It seems my package take a long time to handle something, but as you can see above, I didn't at all.

Answer 1

It seems I have found the answer!

Not:

NextCommandTarget.Exec(pguidCmdGroup, nCmdID, nCmdexecopt, pvaIn, pvaOut);

return VSConstants.S_OK;

But:

return NextCommandTarget.Exec(pguidCmdGroup, nCmdID, nCmdexecopt, pvaIn, pvaOut);