Retrieve value from webservice called from javascript?

Question

Is it possible to retrieve value or date from calling a webmethode from javascript, here is a sample code:

//This method is in a webservice.asmx file.
[WebMethod]
public List<tbl_City> GetAllCitiesByCountry(int countryID)
{

    return Cities.GetAllCitiesByCountry(CountryID: countryID);
}


<script language="javascript" type="text/javascript">

function fillCities() {
    var dropDownList = document.getElementById('<%=DropDownList_Country.ClientID %>');
    var selectedIndex = dropDownList.selectedIndex;
    var value = dropDownList[selectedIndex].value;

   WebService.GetAllCitiesByCountry(parseInt(value.toString()), onSuccess, null, "");

}

   function onSuccess(result){
      alert(result[0].(PropertyName));
      }

The variable x doesn't retrieve anything and I guess that it produce an error. I have tried to define an array but still it didn't work. Any idea ?

Edit:

The above code have been altered and is now an answer to my question along with the answer below which used JQuery.

score 2 · Accepted Answer · answered Dec 08 '11 at 11:19

Use Json response with Jquery, Its realy cool and easy.

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)]
[ScriptService]
public class CitiService : WebService
{
    [WebMethod, ScriptMethod(ResponseFormat = ResponseFormat.Json)]
    public List<tbl_City> GetAllCitiesByCountry(int countryID)
    {
     List<tbl_City> cities = GetCities(countryID);
     JavaScriptSerializer js = new JavaScriptSerializer();
        var jsonObj = js.Serialize(cities);
        Context.Response.Clear();
        Context.Response.Write(jsonObj);
        Context.Response.End();
     }
 }

on ASp.net page

<script language="javascript" type="text/javascript">
 $.ajax({
        url: '<%= ResolveClientUrl("~/CitiService.asmx/GetAllCitiesByCountry") %>',
        dataType: "json",
        data: "{countryID:'100'}",
        success: function (result) {
            alert(result.d.tbl_City.Length) // loop here i.e. foreach to insert in to grid
        }
      });

on the third line of the WebMethod it gave an error: Cannot access a disposed object. Object name: 'DataContext accessed after Dispose.'. — yahya kh, Dec 08 '11 at 12:09
i fixed the problem, turned out that the DataContext dispose of it self after the using statment finishes. — yahya kh, Dec 08 '11 at 12:59
You don't need to manually JSON serialize that. If you just return `cities`, ASP.NET will automatically handle running it through JavaScriptSerializer for you. More info: http://encosia.com/asp-net-web-services-mistake-manual-json-serialization/ — Dave Ward, Feb 08 '12 at 16:34

score 1 · Answer 2 · answered Dec 08 '11 at 11:44

1

you can do this easily with JQuery and ASP.NET webmethods Encosia

answered Dec 08 '11 at 11:44

Zo Has

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score 0 · Answer 3 · edited May 23 '17 at 10:08

0

You need to register your web service with ScriptManager and then call it from the client side. Take a look on this tutorial:

Client-Side Web Service Calls with AJAX Extensions

Also you can use web service with jQuery but in this case you need to switch to JSON: Calling ASMX from jQuery

edited May 23 '17 at 10:08

Community

1
1

answered Dec 08 '11 at 10:25

Samich

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Retrieve value from webservice called from javascript?

3 Answers3

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