How to identify a key in the TextBox? [duplicate]

First you need to enable KeyPreview in the parent control of the TextBox, just set the property to true .

Then you need to use the KeyDown "of the TextBox. This event is triggered whenever a key is pressed in the control and receives as a parameter a KeyEventArgs (usually called e ), KeyEventArgs has a property called KeyCode which in turn is a < a href="https://msdn.microsoft.com/en-us/library/system.windows.forms.keys(v=vs.110).aspx"> Enumeration containing multiple keys

private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
     if(e.KeyCode == Keys.Enter)
     {
         //Fazer algo
     }
}

In the KeyDown event of your Textbox, do the following:

if (e.KeyCode == Keys.Enter)
 {
   //executar alguma acao.
 }

Using jQuery, regardless of browser, the code for the "Enter" is 13. So just test if the button pressed was the 13, as follows:

$(document).keypress(function(e) {
    if(e.which == 13) {
        alert('Você pressionou enter!');
    }
});