Calling C# ASMX Web Service

Question

I have an ASMX web service that I need to utilise as part of a piece of work. I am calling this service via an ASPX page to create new entities on a 3rd party system. I have no access to the underlying code to that service, its simply to allow me to communicate with another system.

Im having trouble finding out if I am calling the service correctly and I wonder if anyone could offer some advice.

I have installed the ASMX page and that has given me a class 'ConfirmConnector' which I call the BeginProcessOperations method. I want to wait on that to return and then parse te results. The results should be in XML which I then step through to get the data I am after.

The trouble is that sometimes this process just dies on me, i.e. when I call my 'EndProcessOperations' method then nothing happens. I dont get an error, nothing - my code just dies and the method returns'

My calling code is:

private void sendConfirmRequest(XmlManipulator requestXML)
{
    file.WriteLine("Sending CONFIRM Request!");
    AsyncCallback callBack = new AsyncCallback(processConfirmXML); // assign the callback method for this call

    IAsyncResult r = conn.BeginProcessOperations(requestXML, callBack, AsyncState);
    System.Threading.WaitHandle[] waitHandle = { r.AsyncWaitHandle }; // set up a wait handle so that the process doesnt automatically return to the ASPX page
    System.Threading.WaitHandle.WaitAll(waitHandle, -1);
}

My handler code is :

 /*
 * Process the response XML from the CONFIRM Connector
 */
private static void processConfirmXML(IAsyncResult result)
{
    try
    {
        file.WriteLine("Received Response from CONFIRM!");
        if(result == null)
        {
            file.WriteLine("RESPONSE is null!!");
        }
        if(conn == null)
        {
            file.WriteLine("conn is null!!");
        }
        file.WriteLine("Is Completed : " + result.IsCompleted);

        XmlNode root =  conn.EndProcessOperations(result);
        file.WriteLine("got return XML");
        //writeXMLToFile("C:/response.xml",root.InnerXml);
        file.WriteLine(root.InnerXml);

Can anyone advise if I am handling this code in the correct way and does anyone have any idea why my code randomly bombs after this line in the handler :

XmlNode root =  conn.EndProcessOperations(result);

Thanks for your help, Paul

Welcome to Stackoverflow! More than often you don't have to include "thanks" etc or your name. We know you are grateful for help so it's implicit, and your name is already at the bottom left of the question. :) — Patrick, Nov 11 '12 at 15:53
oops - sorry, I hadnt realised I forgot it. I re-worded the question about 5 times and must have copied over it. — Paul Lyons, Nov 11 '12 at 15:56
Can you be a bit more elaborate about what you mean by code bombs at that line? — Charles Prakash Dasari, Nov 12 '12 at 18:51
I meant that all the code after that line doesnt appear to execute. My code moves onto the next method - but nothing else in that method. — Paul Lyons, Nov 12 '12 at 19:55

score 0 · Answer 1 · answered Nov 12 '12 at 19:59

thanks for looking, but I solved my problem. The issue appeared to be related to my callback operation.

I changed the code to call my begin & end methods in the same block of code and I havent had an issue since then.

private void sendConfirmRequest(XmlManipulator requestXML)
{
    //ConfirmConnector conn = new ConfirmConnector();
    file.WriteLine("Sending CONFIRM Request!");
    //AsyncCallback callBack = new AsyncCallback(processConfirmXML); // assign the callback method for this call

    //IAsyncResult r = conn.BeginProcessOperations(requestXML, callBack, AsyncState);
    //System.Threading.WaitHandle[] waitHandle = { r.AsyncWaitHandle }; // set up a wait handle so that the process doesnt automatically return to the ASPX page
    //System.Threading.WaitHandle.WaitAll(waitHandle, -1);

    file.WriteLine("Calling BeginProcessOperations");
    IAsyncResult result = conn.BeginProcessOperations(requestXML, null, null);
    // Wait for the WaitHandle to become signaled.
    result.AsyncWaitHandle.WaitOne();
    file.WriteLine("Calling EndProcessOperations");
    XmlNode root = conn.EndProcessOperations(result);
    processConfirmXML(root);

    file.WriteLine("got return XML");
    //writeXMLToFile("C:/response.xml",root.InnerXml);
    file.WriteLine(root.InnerXml);

    // Close the wait handle.
    result.AsyncWaitHandle.Close();
}

Thanks

Paul

Calling C# ASMX Web Service

1 Answers1