在ASP.NET 2.0 WebForms中使用UrlRewrite时如何优雅地处理ReturnUrl

 <system.webServer>
   <rewrite>
     <rules>
        <rule name="UrlRewrite" stopProcessing="true">
         <match url="^(.*)$" />
          <conditions>
            <add input="{QUERY_STRING}" pattern="ReturnUrl=(.*)" />
          </conditions>
         <action type="Redirect" url="{C:1}" appendQueryString="false" />
        </rule>
      </rules>
    </rewrite>
  </system.webServer>
</configuration>

protected void Application_BeginRequest(object sender, EventArgs e)
{
    HttpContext context = HttpContext.Current;
    HttpRequest request = context.Request;

    if (request.QueryString["ReturnUrl"] != null)
    {
        context.Session["ReturnUrl"] = request.QueryString["ReturnUrl"];
    }
}

protected void Page_Load(object sender, EventArgs e)
{
    if (Session["ReturnUrl"] != null)
    {
        Response.Redirect(Session["ReturnUrl"].ToString(), false);
        Session.Remove("ReturnUrl");
    }
}