Question

I am a bit new to threading (not new to C#, just haven’t done much threading). Can someone explain to me why this does not work?

I have a thread which calls a method I will call “Loop”. Loop contains a while loop which will continuously run, and on every loop of the while I want it to check if the A Key is down (using Microsoft’s Keyboard class within the XNA Framework). But for some reason it never registers that anything is being pressed.

static Thread thread = new Thread(Loop);
static bool abort = false;

public static void Begin()
{
    thread.Start();
}

private static void Loop()
{
    while (!abort)
    {
        if (Keyboard.GetState().IsKeyDown(Keys.A))
            Console.WriteLine("A pressed.");
    }
}

Might anyone know why the Console.WriteLine() is never being called?

EDIT:

I guess I should explain a little bit. What I am actually trying to do is create something similar to ActionScript’s events in C#. So I want to pass a “condition” and an “action” to call if that condition is met in this separate class which contains this thread. What this would do would allow me to just add “event listeners” to objects and it would automatically constantly check if one of the events gets triggered, rather than leave it to me to write If statements in code to check for the events.

Upon trying to do so, the first thing I tested was regarding this XNA Keyboard stuff, because it was one of the reasons I originally wanted to build this system, but it didn’t work. So I created the standalone code which i posted above to see if I had made an error in my previous code and it still didn’t work.

Answer 1

I never use XNA so I didn’t really “know” but I’ve run into similar situations where you can’t get keyboard (and other) input from a worker thread. I googled and found that in XNA this does seem to be the case. See this for example

So you need to (and probably want to) process your game input in the GUI thread. Just checking for input on each update tick should be fine. I doubt even if it did work, you would gain any performance – and you might introduce some interesting synchronization bugs 😉

It does look like your creating your worker thread properly – this just isn’t an application for it.