Question

I am using the sample code to dynamically invoke a web service from this site:
http://www.crowsprogramming.com/archives/66

The issue that I am facing is when I use the Class to call a web service from a web application I get the following error: “The remote host cannot be found” and the error happens at the following line of code:
if (!ServiceDescription.CanRead(xmlreader))

But if I use the same code from a windows application to connect to the web service:
http://www.w3schools.com/webservices/tempconvert.asmx?WSDL

it works fine. I am not sure how to resolve this issue. Has anyone else faced the same issue and was able to resolve it then would appreciate some pointers in the right direction.

Answer 1

The issue for me was the Proxy to be used to connect to the internet. The code needs to change at the following two places for the successful operation:

1] The method BuildServiceDescriptionImporter(XmlTextReader xmlreader) was changed to

    private ServiceDescriptionImporter BuildServiceDescriptionImporter( string webserviceUri )
    {
        ServiceDescriptionImporter descriptionImporter = null;

        **WebClient client = new WebClient { Proxy = new WebProxy( string host, int port ) };**

        Stream stream = client.OpenRead( webserviceUri );

        XmlTextReader xmlreader = new XmlTextReader( stream );

        // parse wsdl
        ServiceDescription serviceDescription = ServiceDescription.Read( xmlreader );

        // build an importer, that assumes the SOAP protocol, client binding, and generates properties
        descriptionImporter = new ServiceDescriptionImporter();
        descriptionImporter.ProtocolName = "Soap12";
        descriptionImporter.AddServiceDescription( serviceDescription, null, null );
        descriptionImporter.Style = ServiceDescriptionImportStyle.Client;
        descriptionImporter.CodeGenerationOptions = CodeGenerationOptions.GenerateProperties;

        return descriptionImporter;
    } 

2] The second piece of code that was to be changed was within the public T InvokeMethod<T>( string serviceName, string methodName, params object[] args ) method

add the following code snippet before Invoking the method:

PropertyInfo Proxy = type.GetProperty( "Proxy" );

WebProxy webProxy = new WebProxy( string host, int port);

Proxy.SetValue( serviceInstance, webProxy, null );

After doing those changes I was able to use the code to connect to a remote web service dynamically.

Hope this helps others facing the same issue as I did.