ASP.NET UpdatePanel PreRender问题

Question

I have a website which uses ASP.NET C# for the server side scripting, of which mostly all of the server controls are dynamically added to an UpdatePanel control on the page during the Page_Init event. The following snippet of code:

contentPanel.ContentTemplateContainer.Controls.Add(new LiteralControl("<script>" + clientScriptText + "</script>"));

exists in my Page_Init event (contentPanel is the name of my UpdatePanel). The idea is that this will allow me to run the JavaScript 'alert()' function from the code behind - by setting "alert(\\"--string--\\")" as the value of 'clientScriptText'. I have tested this by putting this code in the UpdatePanel's PreRender event (since it is the UpdatePanel and not the page's PreRender event it shouldn't be ASP.NET page lifecycle factors which are causing the problem, should it?), but although the event fires, when the page is rendered no alert appears. My code for this is shown below:

protected void contentPanel_PreRender(object sender, EventArgs e)
        {
            clientScriptText = "alert(\"Hello\")";
            contentPanel.Update();  //Doesn't work with or without this
        }

Can anybody see what might be wrong? Thank you.

Answer 1

You have to run your JavaScript code with a ScriptManager . UpdatePanel has its own specific lifecycle and rendering techniques, and the ScriptManager was created exactly to solve problems with JS code. Outside an UpdatePanel you should use the ClientScriptManager .