Javascript calls to an Ajax WebMethod. How to get multiple output params returned?

Question

OK, I know how to call a simple old fashion asmx webservice webthod that returns a single value as a function return result. But what if I want to return multiple output params? My current approach is to separate the params by a dividing character and parse them on teh client. Is there a better way.

Here's how I return a single function result. How do I return multiple output values?

<asp:ScriptManager ID="ScriptManager1" runat="server">
    <Services>
        <asp:ServiceReference Path="WebService.asmx" />
    </Services>

    function CallHelloWebMethod() {
        WebService.Hello(txtMyName.value, OnComplete1, OnTimeOut, OnError);
    }

    function OnComplete1(arg) {

        alert(arg);

    }

    function OnTimeOut(arg) {
    }

    function OnError(arg) {
    }

<WebMethod()> Public Function Hello(ByVal MyName As String) As String
    Return "Hello " & MyName
End Function

Answer 1

The normal way to return multiple values is for the AJAX call to return a serialized JSON object.

For example:

{"firstName":"Santa","lastName":"Claus"}

Using the return value is simple, as the client code just has to eval (or JSON.parse) the results to produce a JavaScript object.

Answer 2

Try this.

First establish a class you want to return...

Public Class Person
  Public Name As String
  Public Greeting As String
End Class

Then make the webmethod return the class...

<WebMethod()> _
Public Function Hello(ByVal MyName As String) As Person
    Dim myPerson As New Person
    myPerson.FirstName = MyName 
    myPerson.Greeting = "Hello " & MyName
    Return myPerson
End Function

And update the javascript...

function OnComplete1(arg) {
  alert(arg.Greeting);
}

Note you could also return lists....

<WebMethod()> _
Public Function GetPeople() As Person()
    Dim myPersonList As New Generic.List(Of Person)
    Dim myPerson1 As New Person
    myPerson1.FirstName = "Fred"
    myPerson1.Greeting = "Hello " & MyName
    Dim myPerson2 As New Person
    myPerson2.FirstName = "Bill"
    myPerson2.Greeting = "Hi " & MyName
    myPersonList.Add(myPerson1)
    myPersonList.Add(myPerson2)
    Return myPersonList.ToArray()
End Function