如何区分连接到同一主机的多个 USB 键盘的按键（在 C# 中）

Question

I need to differentiate between a keypress of (at least) two usb-keyboards connected to a single PC. Is there a method/precedure available to decide if key 's' (for example) is pressed either by keyboard A or Keyboard B? (preferable language is C#)

Pseudo-Code:

if (keyPressed == 's')
{ 
   if(keyboardID == 'A')
   {
       print("Key 's' was pressed by Keyboard A");
   }
   else if (keyboardID == 'B')
   {
       print("Key 's' was pressed by Keyboard B");
   }
}

Answer 1

keystrokes are processed by the OS as events

in linux for every input device there is separate event queue in /dev/input/event* ( * means the specific device number)

in linux you can list all input devices with the command sudo lsinput (input-utils)

you can capture the specific events for each of your keyboards, see Linux keyboard event capturing /dev/inputX

in windows this is similar. you can use rawInput and get a handle for each device. deeper information and example codes is in

https://blogs.msdn.microsoft.com/oldnewthing/20160627-00/?p=93755 (" The device handle tells us which keyboard generated the input ... ")

https://www.codeproject.com/Articles/17123/Using-Raw-Input-from-C-to-handle-multiple-keyboard

raw input handling (distinguishing secondary mouse)

https://msdn.microsoft.com/en-us/library/windows/desktop/ms645543%28v=vs.85%29.aspx

Answer 2

Short of getting to the driver level and intercepting the keystroke there, you really can't (I think). I utilize a bluetooth keyboard and a bluetooth keypad and could not find a way to do what you are asking so the number 3 on the keypad would register different than the number 3 on the keyboard keypad.