Disable page refresh after button click ASP.NET

Question

I have an asp button that looks like this:

Default.aspx

<asp:button id="button1" runat="server" Text="clickme" onclick="function" />

Default.aspx.cs

protected void function(object sender EventArgs e)
{
    // Do some calculation
}

However, whenever I press the button, the entire page gets refreshed. I have looked on this site and found many solutions, but none of them really works for my project. Here are some of the suggested solutions:

1. set onclick="return false;" // but then how do I run the function in the code-behind?
2. use !IsPostBack in Page_Load // but the page still refreshes completely. I don't want Page_Load to be called at all.
3. Disable AutoEventWireup. // making this true or false doesn't make a difference.

Does anyone have a solution to this, or is it really impossible?

Answer 1

I would place the control inside of an Update panel. To do so, you would also need a script manager above it, so something like this:

 <asp:ScriptManager runat="server" ID="sm">
 </asp:ScriptManager>
 <asp:updatepanel runat="server">
 <ContentTemplate>
 <asp:button id="button1" runat="server" Text="clickme" onclick="function" />
 </ContentTemplate>
 </asp:updatepanel>

if a control inside the update panel does a postback, it will only reload the part of the page inside of the upate panel.Here is a link you may find useful from the MSDN site.

Answer 2

I think there is a fundamental misunderstanding here of how ASP.Net works.

When a user first requests your page, an instance of your Page class is created. The ASP.Net framework runs through the page lifecycle with this page instance in order to generate html. The html response is then sent to the user's browser. When the browser receives the response it renders the page for the user. Here's the key: by the time rendering is complete, your page class instance was probably already collected by the .Net garbage collector. It's gone, never to be seen again.

From here on out, everything your page does that needs to run on the server, including your method, is the result of an entirely new http request from the browser. The user clicks the button, a new http request is posted to the web server, the entire page lifecycle runs again, from beginning to end, with a brand new instance of the page class, and an entirely new response is sent to the browser to be re-rendered from scratch. That's how ASP.Net (and pretty much any other web-based technology) works at its core.

Fortunately, there are some things you can do to get around this. One option is to put most of your current Page_Load code into an if (!IsPostBack) { } block. Another option is to set up your method with the [WebMethod] attribute and make an ajax request to the method from the button. Other options include calling web services from custom javascript and ASP.Net UpdatePanel controls.

What works best will depend on what other things are on the page that user might have changed.