C# wait for user to finish typing in a Text Box

Question

Is there a way in C# to wait till the user finished typing in a textbox before taking in values they have typed without hitting enter?

Revised this question a little

Answer 1

In UWP, I did a delayed check by making a static lastTimeOfTyping and checking the time when the "TextChanged" event happened. This waits till the static lastTimeOfTyping matches when a new "TextChanged" time matches and then executes the desired function.

    private const int millisecondsToWait = 500;
    private static DateTime s_lastTimeOfTyping;
    private void SearchField_OnTextChanged(object sender, TextChangedEventArgs e)
    {
        var latestTimeOfTyping = DateTime.Now;
        var text = ((TextBox)sender).Text;
        Task.Run(()=>DelayedCheck(latestTimeOfTyping, text));
        s_lastTimeOfTyping = latestTimeOfTyping;
    }

    private async Task DelayedCheck(DateTime latestTimeOfTyping, string text)
    {
        await Task.Delay(millisecondsToWait);
        if (latestTimeOfTyping.Equals(s_lastTimeOfTyping))
        {
            // Execute your function here after last text change
            // Will need to bring back to the UI if doing UI changes
        }
    }

Answer 2

If you are using WPF and .NET 4.5 or later there is a new property on the Binding part of a control named "Delay". It defines a timespan after which the source is updated.

<TextBox Text="{Binding Name, Delay=500}" />

This means the source is updated only after 500 milliseconds. As far as I see it it does the update after typing in the TextBox ended. Btw. this property can be usefull in other scenarios as well, eg. ListBox etc.

Answer 3

As an asynchronous extension method. Adapted from Grecon14's answer.

public static class UIExtensionMethods
{
    public static async Task<bool> GetIdle(this TextBox txb)
    {
        string txt = txb.Text;
        await Task.Delay(500);
        return txt == txb.Text;
    }
}

Usage:

if (await myTextBox.GetIdle()){
    // typing has stopped, do stuff
}