RegisterForEventValidation只能在渲染期间调用

Question

我有一个web方法,将从jquery ajax调用:

[WebMethod]
public string TestMethod(string param1, string param2)
{
    StringBuilder b = new StringBuilder();
    HtmlTextWriter h = new HtmlTextWriter(new StringWriter(b));
    this.LoadControl("~/Pages/Controls/Listing.ascx").RenderControl(h);
    string controlAsString = b.ToString();
    return controlAsString;
}

(这是一种非静态的方法,我们能够击中它.这不是问题)

执行loadControl()方法时,我收到一条错误消息:只能在Render期间调用RegisterForEventValidation.

我已经为当前的aspx,禁用的viewstate包含了EnableEventValidation ="false".但我仍然得到同样的错误.有什么想法吗？

Answer 1

解决方案是禁用Page的事件验证

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

并通过在C#代码后面添加以下方法来覆盖VerifyRenderingInServerForm

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

请参阅以下链接

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

Answer 2

根据Brian的第二个链接,没有进一步跳跃,只需这样做:

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);