Question

I’m currently trying to simulate holding a key down for a specified time. The code runs in its own thread so it’s not interrupting the UI. But the Sleep function is still interrupting the hold sequence. I actually wanted to use Sleep for the time, the key has to be hold down. Is there any way around?

int delay = 2000;

keybd_event(VK_W, 0, KEYEVENTF_EXTENDEDKEY, 0);
System.Threading.Thread.Sleep(delay);
keybd_event(VK_W, 0, KEYEVENTF_KEYUP, 0);
System.Threading.Thread.Sleep(50);

This should simulate holding down the key W, but all it does is pressing it, sleeping (it doesn’t do anything), and then releasing it.

Answer 1

If you want to repeatedly send key-down strokes for a specified number of milliseconds, this could work, but you don’t know how many times it’s really being pressed – you just know that it’s being pressed for the duration of 2000 milliseconds at some unknown discrete rate.

public void DoFor(Action action, int numMilliseconds)
    {
        DateTime start = DateTime.Now;

        while (DateTime.Now.Subtract(start).TotalMilliseconds < numMilliseconds)
        {
            // Not sure - is this relevant on another thread?
            Application.DoEvents();
            // Not sure if this is relevant either since you're on another thread
            Thread.Sleep(1);
            // Do your action
            action();
        }
    }

And you could call it like so:

        DoFor(new Action(() =>
                             {
                                 keybd_event(VK_W, 0, KEYEVENTF_EXTENDEDKEY, 0);
                             }), 2000);
        DoFor(new Action(() =>
                             {
                                 keybd_event(VK_W, 0, KEYEVENTF_KEYUP, 0);
                             }), 50);