Is it unusual for a web service call to have an “out” parameter?

Question

Is it unusual for a web service call to have an \"out\" parameter? If so, why?

I am using C# web service and webserive consumer also will be c# app.

Answer 1

If you are referring to out parameters at the C# level in an ASP.Net web service, I don't think its unusual at all. Your out parameters will simply become child elements of the response element. Here's a short example web service with a single web method that has out parameters:

[WebService(Namespace = "http://begen.name/xml/namespace/2009/10/samplewebservicev1")]
public class SampleWebServiceV1 : WebService
{
    [WebMethod]
    public void
    WebMethodWithOutParameters(out string OutParam1, out string OutParam2)
    {
        OutParam1 = "Hello";
        OutParam2 = "Web!";
    }
}

With the above web method, the SOAP request looks like this:

POST /SampleWebServiceV1.asmx HTTP/1.1
Host: localhost
Content-Type: text/xml; charset=utf-8
Content-Length: length
SOAPAction: "http://begen.name/xml/namespace/2009/10/samplewebservicev1/WebMethodWithOutParameters"



  
    
  

And the response looks like this:

HTTP/1.1 200 OK
Content-Type: text/xml; charset=utf-8
Content-Length: length



  
    
      Hello
      Web!
    
  

Note: this doesn't invalidate the other answers to this question, as they were all considering this from the web service level, not the C# level.