这是我最近做，效果很好，但如果你使用它的ASP.NET应用程序内了解回传将无法工作。

This is what I have done recently, works well, but understand postbacks will not work if you use it inside your ASP.NET app.

 [WebMethod]
 public static string GetMyUserControlHtml()
 {
     return  RenderUserControl("Com.YourNameSpace.UI", "YourControlName");
 }

 public static string RenderUserControl(string assembly,
             string controlName)
 {
        FormlessPage pageHolder = 
                new FormlessPage() { AppRelativeTemplateSourceDirectory = HttpRuntime.AppDomainAppVirtualPath }; //allow for "~/" paths to resolve

        dynamic control = null;

        //assembly = "Com.YourNameSpace.UI"; //example
        //controlName = "YourCustomControl"
        string fullyQaulifiedAssemblyPath = string.Format("{0}.{1},{0}", assembly, controlName);

        Type type = Type.GetType(fullyQaulifiedAssemblyPath);
        if (type != null)
        {
            control = pageHolder.LoadControl(type, null);
            control.Bla1 = "test"; //bypass compile time checks on property setters if needed
            control.Blas2 = true;

        }                          

        pageHolder.Controls.Add(control);
        StringWriter output = new StringWriter();
        HttpContext.Current.Server.Execute(pageHolder, output, false);
        return output.ToString();
 }


public class FormlessPage : Page
{
    public override void VerifyRenderingInServerForm(Control control)
    {
    }
}