Question

I have a webpage (ASP.NET C#) that has a button:

<asp:Button ID="btnHide" runat="server" OnClick="HidePanel" Text="Hide"/>

and I’m doing a JavaScript alert like:

public void HidePanel(object sender, EventArgs e)
{
    Page.ClientScript.RegisterStartupScript(this.GetType(),"Hello","<script type=text/javascript> alert('Hello') </script>");
}

If I modify the function to not have object sender and EventArgs e then I can call it from Page_Load, and it works fine, I get the alert.

As written above I expect to see the alert when I click the button, but it’s not happening. I’m sure it’s something obvious, but I don’t see it.

Answer 1

You can remove the code to register the JavaScript code and instead do this:

<asp:Button ID="btnHide" runat="server" 
   OnClick="HidePanel" Text="Hide" OnClientClick="alert('Hello');" 
   UseSubmitBehavior="false" />      

This:

UseSubmitBehavior="false" 

will cause the button to fire the client-side script, and it will run the server-side code (post-back).