从ASP.NET中的Web服务绑定失败

Question

I have a web service returning in xml data. It only requires one parameter, the userid. It's working fine, until when I want to retrieve data from that web service and append in my C# asp.net. When I run the script, it always fall to error-("no loan found") where there is actually result with the same parameter input.

I have already

• Hardcoded it in my script. (userid-'18450')
• Set result to json at content-type in the script
• Checked the url of my web service

But I have no idea why is it not getting data from the web service. Please help.

My web service code:

  using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.Web.Services;
    using System.Data;
    using System.Data.SqlClient;
    using System.Web.Script.Serialization;
    using System.Web.Script.Services;

namespace WebAppTest2
{
    /// <summary>
    /// Summary description for WebService1
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
    [System.Web.Script.Services.ScriptService]
    public class WebService1 : System.Web.Services.WebService
    {

        public class Record
        {
            public int loanid { get; set; }
            //public string daterequested { get; set; }
            public string name { get; set; }
            public string remark { get; set; }
            //public string loandisplayid { get; set; }
            public string status { get; set; } 
            public string nothing { get; set; }

        }

        [WebMethod]
        public string HelloWorld()
        {
            return "Hello World";
        }

        [WebMethod()]
        public List<Record> GetData(int userid)
        {

            SqlConnection con = new SqlConnection("Data Source=DIT-NB1260382;Initial Catalog=loansystem;Integrated Security=True");
            con.Open();

            SqlCommand cmd = new SqlCommand("Equipment_ListPendingApproval ", con);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@userid", userid);

            SqlDataReader dr = cmd.ExecuteReader();

            List<Record> Record = new List<Record>();

            while (dr.Read())
            {
                Record.Add(new Record()
                {
                    loanid = dr.GetInt32(0),
                    //daterequested = dr.GetString(1),
                    name = dr.GetString(2),
                    //loandisplayid = dr.GetString(3),
                    status = dr.GetString(4),                  
                    remark = dr.GetString(5),


                });
            }

            dr.Close();
            con.Close();
            return Record;
        }
    }
}

My output

My script in the asp.net:

<script>
$(document).ready(function () {
    //var userid = JSON.parse(sessionStorage.getItem('userID'));
    var userid = JSON.parse('18450');
    alert(userid);
    $.ajax({

        type: "POST",
        url: "http://localhost:52928/WebService1.asmx/GetData",
        data: JSON.stringify({ userid: userid }),
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (response) {

            var loans = response.d;


            $.each(loans, function (index, Record) {
                var loanid = this.loanid;
                //construct your html here
                var loanListDiv = "";
                loanListDiv += "<li>";
                loanListDiv += "<a href='requestCollectionPopup.html' data-rel='dialog' data-transition='pop' class='ui-btn ui-btn-icon-right ui-icon-carat-r'>";
                loanListDiv += "<span class='ui-li-count ui-body-inherit' style='border:none; color:#800080; background-color:transparent;'>";
                loanListDiv += Record.status;
                loanListDiv += "</span>";
                loanListDiv += Record.loanid;
                loanListDiv += "</a>";
                loanListDiv += "</li>";

                $("#loansAll").append(loanListDiv).trigger("create");
            });

        },

        error: function (response) {
            alert("No loans Found");
        }
    });
});
</script>

Answer 1

1. looks like your data parameter of $.ajax() method is invalid. It's named userid , not getUserID , right.
2. Also investigate Network tab in Chrome dev tools ( F12 ) and see what actually server responds for this AJAX request.
3. Also type "POST" looks suspicious, when you are able to get response with GET request

Answer 2

To call web service from any service you need to mark that service as script service. Add following attribute to web service and try.

[System.Web.Script.Services.ScriptService]     

See following links

http://www.dotnetjalps.com/2010/08/calling-aspnet-web-service-from-jquery.html http://www.codeproject.com/Articles/529847/Calling-ASP-NET-WebService-from-jQuery