Question about Geoserver response with proxy visit

Question

i always has a question today!

Could not determine geoserver request from http request org.geoserver.platform.AdvancedDispatchFilter$AdvancedDispatchHttpRequest@cc9f79

this is my proxy.ashx:

using System.IO;
using System.Net;
using System.Web;

namespace PlaceNameService
{ 
    public class Proxy : IHttpHandler
    { 
        public void ProcessRequest(HttpContext context)
        {
            string url = context.Request.QueryString["url"];
            WebRequest request = HttpWebRequest.Create(url);
            WebResponse response = request.GetResponse();
            Stream stream = response.GetResponseStream();
            StreamReader reader = new StreamReader(stream); 
            context.Response.ContentType = response.ContentType;
            context.Response.Write(reader.ReadToEnd());
            reader.Close();
            stream.Close();
            response.Close();
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}

****and i visit it as this:****


var xmlPara = "<?xml version='1.0' encoding='UTF-8'?>"
            + "<wfs:GetFeature  service='WFS' version='1.0.0' "
            + "xmlns:wfs='http://www.opengis.net/wfs' "
            + "xmlns:gml='http://www.opengis.net/gml' "
            + "xmlns:ogc='http://www.opengis.net/ogc' "
            + "xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' "
            + "xsi:schemaLocation='http://www.opengis.net/wfs http://schemas.opengis.net/wfs/1.0.0/wfs.xsd'>"
            + "<wfs:Query typeName='"+myLayer.poiLayerName+"' srsName='EPSG:4326'>"
            + "<ogc:Filter>"
            + "<ogc:PropertyIsLike wildCard='*' singleChar='.' escape='!'>"
            + "<ogc:PropertyName>mc</ogc:PropertyName>"
            + "<ogc:Literal>*"+ keyword +"*</ogc:Literal>"
            + "</ogc:PropertyIsLike>"
            + "</ogc:Filter>"
           + "</wfs:Query>"
           + "</wfs:GetFeature>";

var proxy="../Proxy.ashx?url=";
var request = OpenLayers.Request.POST(
        {
            url: proxy+"http://192.168.1.252:8080/geoserver/PlaceNameWorSpace/ows?service=WFS&request=GetFeature",
            data: xmlPara,
            callback: handlerQuery
        });

and then i get the error below！

<ows:ExceptionReport xmlns:ows="http://www.opengis.net/ows/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0.0" xsi:schemaLocation="http://www.opengis.net/ows/1.1 http://192.168.1.252:8080/geoserver/schemas/ows/1.1.0/owsAll.xsd">
<ows:Exception exceptionCode="MissingParameterValue" locator="request">
<ows:ExceptionText>
Could not determine geoserver request from http request org.geoserver.platform.AdvancedDispatchFilter$AdvancedDispatchHttpRequest@cc9f79
</ows:ExceptionText>
</ows:Exception>
</ows:ExceptionReport>

my development enviroment:

iis 7.5+.net framenwork 4+openlayers 2.12+Geoserver 2.2

Can you tell me what should i do,thank you very much!waiting for your help!