calling a c# function from javascript dosent work

Question

I'm buildung a WebApplication in asp.net with c# and i have a problem to call ac# function from the JS.

My code is like this:

in js:

Function doStuff()
{
    var service = new seatService.Service1();
    service.DoWork(id, onSuccess, null, null);
}

and in the service page is:

[ServiceContract(Namespace = "seatService")]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class Service1 
{
    [OperationContract]
    public static  void DoWork(string id)
    {
      //here there is a function that calls the DB
    }
}   

The strange thing is that one of 20 times it actually works (with the same code) but most of the time it fails and I get the message:

uncaught referenceEror - seatService is not defined.

and the status code is 500 Internal Server Error.

Since it sometime working and sometime doesn't - where is my problem?

Answer 1

You want to use PageMethods for this. Here's some sample code to demonstrate:

public partial class ContactUs : System.Web.UI.Page
{
   [WebMethod]
   public static void SendForm(string name, string email, string message)
   {
       if (string.IsNullOrEmpty(name))
           throw new Exception("You must supply a name.");    
       if (string.IsNullOrEmpty(email))
           throw new Exception("You must supply an email address.");   
       if (string.IsNullOrEmpty(message))
           throw new Exception("Please provide a message to send.");

       //call your web service here, or do whatever you wanted to do
   }
}

From JavaScript:

SendForm = function() {
   var name = $get("NameTextBox").value;
   var email = $get("EmailTextBox").value;
   var message = $get("MessageTextBox").value;

   PageMethods.SendForm(name, email, message, OnSucceeded, OnFailed);
}    
OnSucceeded = function() {
   $get("ContactFieldset").innerHTML = "<p>Thank you!</p>";
}    
OnFailed = function(error) {
   alert(error.get_message());
}