Render control programmatically (using LoadControl) while adhering the page lifecycle

Question

I'm trying to use LoadControl to get a custom control in code for programmatic rendering purposes. However I notice that the OnInit method of my custom control is not being called. Am I missing an essential step here?

//Loading the control
Page h = HttpContext.Current.Handler as Page;

UserControl userControl = (UserControl)h.LoadControl(pathToControl);
h.Controls.Add((Control)userControl);

//Rendering the control
StringWriter stringWriter = new StringWriter();
HtmlTextWriter writer = new HtmlTextWriter((TextWriter) stringWriter);
userControl.RenderControl(writer);
var result = stringWriter.ToString();

This is where the code above is called

[ScriptService]
public partial class Ajax : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    [WebMethod]
    [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
    public static object AjaxMethod(string productCode) {
        //here...
    }
}

When in the lifecycle of the page is this running? And what does oninit look like in the custom control? — Brian Mains, Feb 11 '13 at 13:55
`OnInit` in the control calls a static method in some library and after that it calls `base.OnInit`. — ReFocus, Feb 11 '13 at 13:56
See my updated question to see where the method is called... — ReFocus, Feb 11 '13 at 13:58

score 2 · Accepted Answer · edited May 23 '17 at 10:32

2

So you are making a PageMethods call to the server, and want to stream back the markup for a custom control update, is what it looks like. PageMethods do not execute a lifecycle, therefore it will never fire the OnInit event handler. People have used this same technique using JQuery or an HTTP handler, and some examples of how they did it was here:

edited May 23 '17 at 10:32

Community

1
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answered Feb 11 '13 at 14:21

Brian Mains

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I solved it using the `ServerUtility.Execute` method which invokes the lifecycle. Thanks! – ReFocus Feb 11 '13 at 14:52

Render control programmatically (using LoadControl) while adhering the page lifecycle

1 Answers1