Why my textbox TextChanged event gets fired after I enter “only” one character in my text box?

Question

private void NameVal_TextChanged(object sender, EventArgs e)
    {
        String text = NameVal.Text;

    }

As soon as I enter the first letter o

Answer 1

If you want to determine when the user has finished typing, you can catch the leave event instead - this is fired when the focus is lost on that text box - ie the user clicks outside of the textbox:

private void NameVal_Leave(object sender, EventArgs e)
{
    //Do your stuff
    String text = NameVal.Text;
}