如何在asp.net webform中的jquery ajax中使用c＃datatable？

Question

Guys i want to send a datatable from c# to jquery Ajax. if i send string it works properly and if i send datatable it gives the output error below i have posted!

[WebMethod]
            public static DataTable getGuestByGuestIDFront(string guest_id)
            {

                DataTable dt621 = BAL.getGuestByGuestID(guest_id);
                return dt621;
            }

Jquery

  < script type = "text/javascript" >

 function guest_search() {
     //      debugger;
     var guest_id = $('#guest_id').val();
     jQuery.ajax({
         url: 'Walkin6.aspx/getGuestByGuestIDFront',
         type: "POST",
         data: "{'guest_id':" + guest_id + "}",
         contentType: "application/json; charset=utf-8",
         dataType: "json",
         success: function (data) {
             debugger;
             // TabItem2_click();
             console.log(data.d);
             //   alert("Booking ID " + data.d);
             // $("#message").html((data.d));

             //   $(this).prop("disabled", true);

         },
         error: function (result) {
             console.log('Failed' + result.responseText);
         }

     });
 } < /script>

This is the output!

Failed{"Message":"A circular reference was detected while serializing an object of type \'System.Reflection.RuntimeModule\'.","StackTrace":" at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeCustomObject(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Seria lization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeEnumerable(IEnumerable enumerable, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeCustomObject(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat)\\r\\n at System .Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeCustomObject(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberI nfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeCustomObject(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeCustomObject(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFo rmat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeEnumerable(IEnumerable enumerable, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeCustomObject(Object o, StringBuilder sb, Int32 depth, Hashtable object sInUse, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.Serialize(Object obj, StringBuilder output, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.Serialize(Object obj, SerializationFormat serializationFormat)\\r\\n at System.Web.Script.Serialization.JavaScriptSerializer.Serialize(Object obj)\\r\\n at System.Web.Script.Services.RestHandler.InvokeMethod(HttpContext context, WebServiceMethodData methodData, IDictionary`2 rawParams)\\r\\n at System.Web.Script.Services.RestHan dler.ExecuteWebServiceCall(HttpContext context, WebServiceMethodData methodData)","ExceptionType":"System.InvalidOperationException"}

is there anyway to work with c# datatable in jquery ajax!!

Answer 1

c# code

  [WebMethod]
        public static string getGuestByGuestIDFront(string guest_id)
        {
            DataTable dt = BAL.getGuestByGuestID(guest_id);

            List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();
            Dictionary<string, object> row = null;

            foreach (DataRow dr in dt.Rows)
            {
                row = new Dictionary<string, object>();
                foreach (DataColumn col in dt.Columns)
                {
                    row.Add(col.ColumnName, dr[col]);
                }
                rows.Add(row);
            }

            string json = js.Serialize(rows);
            return json;
        }

javascript code for success:

 success: function (serverdata) {

    var tableData = $.parseJSON(serverdata.d);
  }

Answer 2

You need to do something like this

[WebMethod]
public static string doSomething(int id)
{
   DataTable dt621 = BAL.getGuestByGuestID(guest_id);

   return JsonConvert.SerializeObject(dt621);
}

and then in success call of ajax

 success: function (data) {

    var tableData = $.parseJSON(data.d);//if you want your data in json
  }

Answer 3

The error says there are circular references. If you know they actually do not exist serialize the object with Json.NET as the response to AJAX call or create simpler DTO. I had similar problem with default serializer from .net framework - it couldn't serialize an object because of CR which actually weren't there! Shifting to Json.NET fixed the problem for me.