C# - How to allow multiple filetypes in an OpenFileDialog?

Question

I knew this once but I keep forgetting; How do I allow multiple filetypes in one filter entry of the OpenFileDialog?

Text files|*.txt          // this is OK.

Text files|*.txt,*.text   // how do I get this??

Answer 1

Semicolon:

files|*.txt;*.text

Answer 2

What if I want to exclude some file types. For example, i want the open file dialog to show all files except .exe, .bat, etc.

So basically a filter to exclude some file types.