Why do I get two messages on `AltGr` being pressed?

Question

Why do I get two messages on AltGr being pressed?

I have the following hook:

LRESULT CALLBACK MyClass::KeyboardShotcutsHook(int code, WPARAM w         


        

Answer 1

Because AltGr and Alt+Ctrl are equivalent (in Windows). Two key stroke sequences mean the same thing, and Alt+Ctrl won (probably because there is no AltGr on the US keyboard layout - that's my guess).

If you want to check for AltGr, check if Ctrl is pressed whenever Alt shows up in your hook.