RegisterForEventValidation can only be called during Render

Question

I have a webmethod which will be called from jquery ajax:

[WebMethod]
public string TestMethod(string param1, string param2)
{
    StringBuilder b = new Stri         


        

Answer 1

As per Brian's second link, without hopping further, just do this:

StringBuilder sb = new StringBuilder();
StringWriter sw = new StringWriter(sb);
Html32TextWriter hw = new Html32TextWriter(sw);

Page page = new Page();
HtmlForm f = new HtmlForm();
page.Controls.Add(f);
f.Controls.Add(ctrl);
// ctrl.RenderControl(hw); 
// above line will raise "RegisterForEventValidation can only be called during Render();"
HttpContext.Current.Server.Execute(page, sw, true);
Response.Write(sb); 

Answer 2

Solution is to disable the Page's Event Validation as

<%@ Page ............ EnableEventValidation="false" %>

and Override VerifyRenderingInServerForm by adding following method in your C# code behind

public override void VerifyRenderingInServerForm(Control control)
{
    /* Confirms that an HtmlForm control is rendered for the specified ASP.NET
       server control at run time. */
}

Refer the Below Link

http://www.codeproject.com/Questions/45450/RegisterForEventValidation-can-only-be-called-duri