Question

I’ve got a usercontrol that has a <asp:TextBox> with autopostback set to true. When the user types text in and moves off the textbox, asp.net fires a postback event. However, it isn’t handled specifically by the textbox, but is instead simply a postback – the page_load fires and then life goes on.

What I need is a way to know that this textbox fired the event. I then want to fire my own custom event so that my main page can subscribe to it and handle the event when the textbox changes.

At first I thought I could capture the sender – I was assuming that the sender would be the textbox, but it appears to be the page itself.

Anyone have any thoughts?

Answer 1

I think you’re missing something, so I want to explain it step by step :

your textbox should be something like that :

<asp:TextBox runat='server' ID='TextBox1' AutoPostBack='true'  OnTextChanged='TextBox1_TextChanged'></asp:TextBox> 

and in your codebehind you shhould have an event like that :

protected void TextBox1_TextChanged(object sender, EventArgs e) {     string str = TextBox1.Text; } 

NOTE : if you want to attach your event in code-behind you can do this by :

TextBox1.TextChanged +=new EventHandler(TextBox1_TextChanged); 

but if you talking about custom controls, you should implement IPostBackDataHandler interface to raise events.