How to achieve the tags auto suggest of code project using C# windows application?

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C#

Windows

Anyone who tried to make the Auto Suggest text box of Code Project's Tags text box? There you can have a list(drop down) of matching typed characters and separated by a comma and a space(", "). And every after a comma and a space you can again have the auto suggest drop down list.

What I have tried:

I'm trying to do it but it a more simple way for now I'm just using the autocomplete string collection. I'm in need of help to achieve Code Projects's Tags Auto Suggest Textbox.