Passing parameters from frontend using webservice

Question

User279786496 posted

Hi,

    I have a java script file where we are getting selected Id's and these id's I want to pass to web service method where we are calling stored procedure (Sql server) these id's values should go as parameter to stored procedure and retrieve the data from procedure and bind in the drop down list.

Here is the code

Java script file
 
      var params = [];
        params.push(CreateNewParameter("IdList", GetConcatenateIdsToDownload(selectedId)))
        var dsConfig = GetDataSource(StudentSvcUrl + "GetStudentParameter", params);

Interface

Interface

        [OperationContract(Name = "GetStudentParameter")]         [WebInvoke(Method = "POST", BodyStyle = WebMessageBodyStyle.WrappedRequest, RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]          StdGenericList<StdDropdownListItem> GetStudentParameter(Dictionary<int, string> selectedId);

Svc Method

public StdGenericList<StdDropdownListItem> GetStudentParameter(Dictionary<string, string> selectedId)
{

What ever Id's we are selected that is coming from JS file, The issue is with svc method - I am not able to get it in dictionary (selectedId) it is showing as NULL when I debug it.

Answer 1

User475983607 posted

BerrySmith

What ever Id's we are selected that is coming from JS file, The issue is with svc method - I am not able to get it in dictionary (selectedId) it is showing as NULL when I debug it.

This generally indicates the data is not properly formatted.  Unfortunately, there is not enough information in the POST to guess where the bug is located.

Also the Interface does not match the implementation and should not compile.  That's a bit concerning because it means the problem description does not match the POSTed code. 

Answer 2

User1168443798 posted

Hi BerrySmith,

>> The issue is with svc method - I am not able to get it in dictionary (selectedId) it is showing as NULL when I debug it.

Could you run your service? I found you define Interface with “Dictionary<int, string> selectedId”, but you implement it by “Dictionary<string, string> selectedId”. It will throw error.

I make a test to achieve your requirement to pass Dictionary from JS to WCF Rest Service.

1. Create a WCF Service

        public Dictionary<int, string> GetStudentParameter(Dictionary<int, string> selectedId)
        {
            Dictionary<int, string> d = new Dictionary<int, string>();
            d.Add(1,"D1");
            d.Add(2, "D2");
            return d;
        }

2. Call Service from JS

        function SendDictionary() {
            console.log("Hello");
            var selectedId = [];
            selectedId.push({ Key: 1, Value: "S1" });
            selectedId.push({ Key: 2, Value: "S2" });
            $.ajax({
                url: '/Service1.svc/GetStudentParameter',
                data:'{"selectedId":'+  JSON.stringify(selectedId) +'}',
                contentType: 'application/json',
                type: 'POST',
                dataType: 'json',
                success: function (result) {
                    console.log(result)
                }
            });
        }

Best Regards,

Edward