从自定义处理程序调用默认的asp.net HttpHandler

Question

我正在将ASP.NET路由添加到较旧的webforms应用程序中.我正在使用自定义HttpHandler来处理所有内容.在某些情况下,我想将特定路径映射回aspx文件,因此我需要将控制权传递回asp.net的默认HttpHandler.

我得到的最接近的是这个

public void ProcessRequest(HttpContext context) {
    // .. when we decide to pass it on

    var handler = new System.Web.UI.Page();
    handler.ProcessRequest(context);

    MemoryStream steam = new MemoryStream();
    StreamWriter writer = new StreamWriter(stream);
    HtmlTextWriter htmlWriter = new HtmlTextWriter(writer);
    handler.RenderControl(htmlWriter);


    // write headers, etc. & send stream to Response
}

它没有做任何事情,流没有任何输出.MS的System.Web.UI.Page文档(作为IHttpHandler)说"不要调用ProcessRequest方法.它是供内部使用的".

从环顾四周看来你可以用MVC做到这一点,例如:MvcHttpHandler似乎没有实现IHttpHandler

还有一件事System.Web.UI.PageHandlerFactory似乎只会为aspx文件生成一个Page处理程序,但它是内部的,我不能直接使用它.

此页面:http://msdn.microsoft.com/en-us/library/bb398986.aspx引用"默认的asp.net处理程序",但不识别类或给出任何可能如何使用它的指示.

有关如何做到这一点的任何想法？可能吗？

Answer 1

坚持不懈!这实际上是有效的,因为这些信息似乎几乎无处可用,我以为我会回答我自己的问题.感谢Robert关于使用内部构造函数实例化的这篇文章,这是关键.

http://www.rvenables.com/2009/08/instantiating-classes-with-internal-constructors/

public void ProcessRequest(HttpContext context) {
    // the internal constructor doesn't do anything but prevent you from instantiating
    // the factory, so we can skip it.
    PageHandlerFactory factory =
        (PageHandlerFactory)System.Runtime.Serialization.FormatterServices
        .GetUninitializedObject(typeof(System.Web.UI.PageHandlerFactory));

     string newTarget  = "default.aspx"; 
     string newQueryString = // whatever you want
     string oldQueryString = context.Request.QueryString.ToString();
     string queryString = newQueryString + oldQueryString!="" ? 
         "&" + newQueryString :
         "";

     // the 3rd parameter must be just the file name.
     // the 4th parameter should be the physical path to the file, though it also
     //   works fine if you pass an empty string - perhaps that's only to override
     //   the usual presentation based on the path?

     var handler = factory.GetHandler(context, "GET",newTarget,
         context.Request.MapPath(context,newTarget));

     // Update the context object as it should appear to your page/app, and
     // assign your new handler.

     context.RewritePath(newTarget  , "", queryString);
     context.Handler = handler;

     // .. and done

     handler.ProcessRequest(context);
}

...就像一些小奇迹一样,aspx页面完全处理并呈现,无需重定向.

我希望这只适用于IIS7.