[jquery] Fire event on enter key press for a textbox

I have the following asp.net textbox control.

<asp:TextBox ID="txtAdd" runat="server" />

After the user writes something in this textbox and presses the ENTER key, I want to run some code from codebehind.

What should I do?

Using jQuery I captured ENTER key and fired some hidden button event

$(document).ready(function(){ 
   $(window).keydown(function(e){
      if(e.keyCode == 13) $('#<% addbtn.ClientID %>'.click();
   }); 
});

Is there any better way ?

my jQuery powered solution is below :)

Text Element:

<asp:TextBox ID="txtTextBox" ClientIDMode="Static" onkeypress="return EnterEvent(event);" runat="server"></asp:TextBox>
<asp:Button ID="btnSubmitButton" ClientIDMode="Static" OnClick="btnSubmitButton_Click" runat="server" Text="Submit Form" />

Javascript behind:

<script type="text/javascript" language="javascript">
    function fnCheckValue() {
        var myVal = $("#txtTextBox").val();
        if (myVal == "") {
            alert("Blank message");
            return false;
        }
        else {
            return true;
        }
    }

    function EnterEvent(e) {
        if (e.keyCode == 13) {
            if (fnCheckValue()) {
                $("#btnSubmitButton").trigger("click");
            } else {
                return false;
            }
        }
    }

    $("#btnSubmitButton").click(function () {
        return fnCheckValue();
    });
</script>

<input type="text" id="txtCode" name="name" class="text_cs">

and js:

<script type="text/javascript">
$('.text_cs').on('change', function () {
var pid = $(this).val();
console.log("Value text: " + pid);
});
</script>

1. Wrap the textbox inside asp:Panel tags

2. Hide a Button that has a click event that does what you want done and give the <asp:panel> a DefaultButton Attribute with the ID of the Hidden Button.

<asp:Panel runat="server" DefaultButton="Button1">
   <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>    
   <asp:Button ID="Button1" runat="server" style="display:none" OnClick="Button1_Click" />
</asp:Panel>

ahaliav fox 's answer is correct, however there's a small coding problem.
Change

<%=Button1.UniqueId%> 

to

<%=Button1.UniqueID%> 

it is case sensitive. Control.UniqueID Property

Error 14 'System.Web.UI.WebControls.Button' does not contain a definition for 'UniqueId' and no extension method 'UniqueId' accepting a first argument of type 'System.Web.UI.WebControls.Button' could be found (are you missing a using directive or an assembly reference?)

N.b. I tried the TextChanged event myself on AutoPostBack before searching for the answer, and although it is almost right it doesn't give the desired result I wanted nor for the question asked. It fires on losing focus on the Textbox and not when pressing the return key.

My 2c.. I have used javascript, but found it did things that were not quite expected.

USE the panel's defaultButton attribute/property as many of the above posts suggest. It is reliable (EASY) and works in all the browsers I have tested it on.

You could wrap the textbox and button in an ASP:Panel, and set the DefaultButton property of the Panel to the Id of your Submit button.

<asp:Panel ID="Panel1" runat="server" DefaultButton="SubmitButton">
    <asp:TextBox ID="TextBox1" runat="server" />
    <asp:Button ID="SubmitButton" runat="server" Text="Submit" OnClick="SubmitButton_Click" />
</asp:Panel>

Now anytime the focus is within the Panel, the 'SubmitButton_Click' event will fire when enter is pressed.

<asp:Panel ID="Panel2" runat="server" DefaultButton="bttxt">
    <telerik:RadNumericTextBox ID="txt" runat="server">
    </telerik:RadNumericTextBox>
    <asp:LinkButton ID="bttxt" runat="server" Style="display: none;" OnClick="bttxt_Click" />
</asp:Panel>

protected void txt_TextChanged(object sender, EventArgs e)
{
    //enter code here
}

Try follow: Aspx:

<asp:TextBox ID="TextBox1" clientidmode="Static" runat="server" onkeypress="EnterEvent(event, someMethod)"></asp:TextBox>    
<asp:Button ID="Button1" onclick="someMethod()" runat="server" Text="Button" />

JS:

function EnterEvent(e, callback) {
        if (e.keyCode == 13) {
            callback();
        }
    }

Try this option.

update that coding part in Page_Load event before catching IsPostback

 TextBox1.Attributes.Add("onkeydown", "if(event.which || event.keyCode){if ((event.which == 13) || (event.keyCode == 13)) {document.getElementById('ctl00_ContentPlaceHolder1_Button1').click();return false;}} else {return true}; ");