How to gather timing information of keystrokes using C#?

Question

I want to build a simple C# Windows Form Application that gathers user's keystrokes data.

Basically, the user needs to type in a word with length 10. I want to record each key's holding time, keydown to keydown time and keyup and keydown for adjacent keystrokes (so there are 10 + 9 + 9 = 28 measurements).

Could anyone tell me how to capture this information using text box events?

Thanks in advance

If you have to work with this sort of thing often and you're feeling brave, you could have a look at Reactive Extensions (http://msdn.microsoft.com/en-us/data/gg577609.aspx). That's pretty much exactly what it was invented for. — Kirill Shlenskiy, Nov 25 '13 at 05:04

Nikolai Samteladze · Accepted Answer · 2013-11-25T04:43:05.870

4

You can handle KeyUp and KeyDown events on your TextBox. You can get current timestamp using DateTime.Now.

Store your last KeyUp and KeyDown events time and add measurements like this:

private DateTime? keyUpTime = null;
private DateTime? keyDownTime = null;

private List<double> keyDownKeyUpMeasurements = new List<double>();
private List<double> keyDownKeyDownMeasurements = new List<double>();
private List<double> keyUpKeyDownMeasurements = new List<double>();

private void textBox_KeyDown(object sender, KeyEventArgs e)
{
    DateTime prevKeyDownTime = keyDownTime;
    keyDownTime = DateTime.Now;

    if (prevKeyDownTime != null)
    {
        keyDownKeyDownMeasurements
            .Add(keyDownTime.Subtract(prevKeyDownTime).TotalMilliseconds);
    }

    if (keyUpTime != null)
    {
        keyUpKeyDownMeasurements
            .Add(keyDownTime.Subtract(keyUpTime).TotalMilliseconds);
    }
}

private void textBox_KeyUp(object sender, KeyEventArgs e)
{
    keyUpTime = DateTime.Now;
    keyDownKeyUpMeasurements
        .Add(keyUpTime.Subtract(keyDownTime).TotalMilliseconds);
}

edited Nov 25 '13 at 04:43

answered Nov 25 '13 at 04:23

Nikolai Samteladze

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Thanks, I think it can work. I'm trying to ignore bad input. Do you know how to use KeyEventArgs.KeyValue? Is "string ch = ((Char)e.KeyCode).ToString()" correct? – Freya Ren Nov 25 '13 at 04:46
I doubt that cast `(Char)e.KeyCode` will work. `KeyCode` returns `Keys` enum value. What are you trying to achieve? To filter specific characters you can use something like `e.KeyCode != Keys.A`. – Nikolai Samteladze Nov 25 '13 at 04:54
The user's input should be a fixed words with length of 10 (like "abcdefghij"). So that I need to check whether the user press the right key. I don't want to use a long condition like if(e.KeyCode!=keys.A && e.KeyCode!=Keys.B &&......) – Freya Ren Nov 25 '13 at 05:05
You can use something like `bool stringIsAllLetters = yourString.All(c => Char.IsLetter(c));`. – Nikolai Samteladze Nov 25 '13 at 05:16

How to gather timing information of keystrokes using C#?

1 Answers1