WebForms TextBox Lost Focus Event

Question

I'm trying to add an event handler to a TextBox control that is called when the text box loses focus. Is this possible?

I know WinForms has a LostFocus event. I'm looking for something similar in ASP.NET WebForms.

Dgan · Answer 1 · 2014-03-19T19:41:52.753

2

You can Use OnBlur

<asp:TextBox id="TextBox1" runat="server" onblur="Javascript:alert('1234');" />

Or EDIT: Server side

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            TextBox1.Attributes.Add("onblur", "alert('hi User')");
    }
}

edited Mar 19 '14 at 19:41

answered Mar 19 '14 at 19:34

Dgan

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Is it possible to call C# code at all with this method? – muttley91 Mar 19 '14 at 19:36
@rar you can add your server side code (C#) with above – Dgan Mar 19 '14 at 19:42
Do you mean add the JavaScript server side, or is there a way to add C# code to the onblur event? – muttley91 Mar 19 '14 at 19:57
If You want to Execute Something From Server Side then You can take One asp Button Make it display none and call its postback event onblur of textbox – Dgan Mar 19 '14 at 20:00
The server side solution doesn't seem to work if I want to add text from another page element. – muttley91 Mar 19 '14 at 21:04
if You Wants to Display Some Text from another Page Then You have to Maintain State at Server Side http://www.codeproject.com/Articles/492397/State-Management-in-ASP-NET-Introduction – Dgan Mar 20 '14 at 05:09

score 1 · Answer 2 · edited May 23 '17 at 12:30

1

I think you are going to have to use javascript for this and the event you will need to search and look up would be onBlur() I believe. If you need an example, I might be able to scrounge one up for you. But here are some links..

W3Schools

Stack

Java Page

Hope these help.

edited May 23 '17 at 12:30

Community

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answered Mar 19 '14 at 19:33

Humpy

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score 0 · Answer 3 · answered Mar 19 '14 at 19:35

This would be the blur event, and it's a client-side event on the resulting input element instead of a server-side event on the TextBox control.

For example, let's say you have a TextBox with the ID of "TextBox1", and let's assume jQuery is included in your project template (because it probably is), then in your client-side code you might have something like this:

$('#<%= TextBox1.ClientID %>').blur(function () {
    // code to respond to the event
});

This would execute any code in that function whenever the input for that TextBox control loses focus. Notice the use of a small block of server-side code to output the server-side control's client-side ID.

WebForms TextBox Lost Focus Event

3 Answers3