ASPX Textbox: Execute method on return keypress

Question

I have a search box that doesn't have a submit button, I need to be able to hit enter and then execute a method, how do I do this?

Answer 1

Use the TextChanged event, and set the AutoPostBack property to true.

Answer 2

You could add a hidden button to the page and wire-up your method to that button's click event. Then add a small bit of javascript to trigger that button's postback action when you press enter inside the textbox.

this.myTextBox.Attributes.Add(
    "onkeydown", 
    "return keyDownHandler(13, 'javascript:" 
     + this.Page.ClientScript.GetPostBackEventReference(this.myButton, string.Empty).Replace("'", "%27") 
     + "', event);");

(You could also replace the hard-coded 13 with Windows.Forms.Keys.Enter, if you'd prefer an easier to read version.)

Where keyDownHandler is a JavaScript function like this:

function keyDownHandler(iKeyCode, sFunc, e) { 
    if (e == null) { 
        e = window.event; 
    } 
    if (e.keyCode == iKeyCode) { 
        eval(unescape(sFunc)); return false; 
    } 
}

Note, this is based on the implementation of DotNetNuke's ClientAPI web utility.

Answer 3

you could also do something simple like this with CSS:

<asp:Panel DefaultButton="myButton" runat="server">
    <asp:TextBox ID="myTextBox" runat="server" />
    <asp:Button ID="myButton" runat="server" onclick="myButton_Click" style="display: none; "  />
</asp:Panel>

The panel may or may not be necessary depending on your implementation and surrounding controls, but this works and does a postback for me.