Checks the key definitions table to see if a definition exists for the specified key on the selected embedded or attached keyboard.
HRESULT KeyExistsEx( BYTE keyboard,
BYTE plane,
BYTE page,
BYTE usage,
bool* result
);
keyboard
Indicates the keyboard to be used for this operation:
plane
Keyboard plane (Normal, Orange, or Green) for the specified key definition.
page
Page number defining the key.
usage
Usage number defining the key.
result
Returns true if the key is defined.
S_OK
The function succeeded.
Other
The function failed. Use the Microsoft errlook.exe utility to determine the meaning of this value.
If more than one external keyboard is attached to the computer, call GetKeyboardIDEx to return the unique identifier for each attached keyboard.