jQuery AJAX Call for posting data to ASP.Net page ( not Get but POST)

the following jQuery AJAX call to an ASP.Net page.

$.ajax({
                async: true,
                type: "POST",
                url: "DocSummaryDataAsync.aspx", //"DocSummary.aspx/GetSummaryByProgramCount",
                contentType: "application/json; charset=utf-8",
                data: kendo.stringify({ vendorId: supplierId, businessUnit: busUnit, productSegmentId: prodSegmentId, programId: progId, productManagerId: prodManagerId, companyIds: compIds, expired: exp.toString(), requestType: 'TotalCount' }),
                success: function (msg) {
                    // alert('in success of getcount');

                },
                error: function (XMLHttpRequest, textStatus, errorThrown) {
                    // alert('in failure of getcount');


                }
            });

When I try to retrieve from Request object, the posted data, it does not show up. My aspx page code is as below. I am sending each of posted data in Json format to the page, yet it doesn't show up in code-behind of page. Is there some extra setting in jQuery ajax call that I am missing?

protected void Page_Load(object sender, EventArgs e)
    {
        Response.ContentType = "application/json";

        string requestType = Request.Params["requestType"];


        //populate variables from posted data
        string vendorId = Request.Params["vendorId"];
        string businessUnit = Request.Params["businessUnit"];
        string productSegmentId = Request.Params["productSegmentId"];
        string commitmentProgramId = Request.Params["programId"];
        string productManagerId = Request.Params["productManagerId"];
        string companyIds = Request.Params["companyIds"];
        string expired = Request.Params["expired"];
     }

UPDATE 1: Stephen's answer is the best approach to this, especially the approach that does ProcessRequest. However, I did find a small trick that will allow data to be posted to ASP.Net in the usual traditional manner i.e. like Request["vendorId"] etc. To enable such posting of data from any jQuery ajax request, you simply need to make sure that the following 2 points are applied to your jQuery ajax call:

1. The content-type should be left out of your jQuery ajax call Or if you want to include it then it should not be set to "application/json; charset=utf-8" but to "application/x-www-form-urlencoded; charset=UTF-8". Content-type, as per my understanding is telling the ASP.Net page the type of data that is being sent, and not the type of data that is expected of the page.
2. The data part of jQuery ajax should not have the data names enclosed in quotes. So data: {"venorId":"AD231","businessUnit":"123"} should be replaced by data: {vendorId:"AD231",businessUnit:"123"}. In this example the data names are vendorId and businessUnit, which can be accessed in your ASP.Net code-behind using usual ASP.Net syntax like Request["vendorId"] and Request["businessUnit"].

转自：http://stackoverflow.com/questions/14095041/jquery-ajax-call-for-posting-data-to-asp-net-page-not-get-but-post