With WPF, you can checkup
System.Windows.Input.Keyboard.IsKeyToggled(Key.Insert), see
http://msdn.microsoft.com/en-us/library/system.windows.input.keyboard.iskeytoggled.aspx[
^].
Unfortunately, there is no such thing in
System.Windows.Forms. One work-around is using Windows API
GetKeyState, via P/Invoke, see
http://msdn.microsoft.com/en-us/library/windows/desktop/ms646301%28v=vs.85%29.aspx[
^]. For toggled state you need to examine low-order bit of the result, so mask it like this result = GetKeyState(/*...*/) & 1.
Unfortunately, using P/Invoke would break platform compatibility — the code will work only on Windows (a Forms application could work well on many platforms without recompilation under Mono,
http://en.wikipedia.org/wiki/Mono_%28software%29[
^],
http://www.mono-project.com/[
^]). By this reason, your approach which does not require P/Invoke is better.
There is one more reason: every instance of
System.Windows.Forms.RichTextBox control has its own insert state that is independent of the global insert state as well as the insert state of all other
RichTextBox controls. Take a look at this text:
http://vb.mvps.org/hardcore/html/controllingrichtextboxinsertstate.htm[
^] (sorry, it's in VB.NET, but you can understand it). See also this discussion:
http://www.codeguru.com/forum/showthread.php?t=276369[
^].
You are right about unnecessary duplication of a functionality, but this functionality is not expose, which is a shame, I would say. So, you will need to handle some key event anyway, because even when you can poll the keyboard status, you need some event to trigger your check.
—SA
Submit an article or tip