Calling a Web Service using VB6 with SOAP 3.0

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This article shows you how to create a client that calls a web service from Visual Basic 6 using SOAP 3.0. If you are still using VB 6.0 or C++ and don't plan to move into VB.NET, you will find this method very useful.

Introduction

In an earlier article the method of calling a web service from a client created using Microsoft Visual Studio 2003 IDE was described. The IDE offers an excellent method to get a reference to the necessary proxy by way of the WSDL utility. This is carried out by adding a web reference to the client application.

This article shows how you may create a client that calls the web service from Visual Basic 6 using Soap 3.0. By providing Soap 3.0,  Microsoft provides VB programmers with the ability to tap web services. This is most useful to those who are still using VB 6.0 or C++ and are not contemplating a move into VB.NET.

This tutorial assumes that web services have been created using any of the programming languages and that a wsdl web reference is available. In particular it creates clients for the web services created using the ColdFusion service with just one method, and another web service using VB.NET with two methods. Examples of early binding and late binding are also shown for the web service created with ColdFusion.

SOAP basics

SOAP, which stands for Simple Object Access Protocol, is a vendor- and platform-agnostic protocol which uses XML and HTTP (SOAP Specification 1.0) to access resources (servers, services and objects) through firewalls in a distributed environment. Later SOAP specifications do not mandate the use of HTTP,  and other protocols such as SMTP and FTP can also be used.  Please review SOAP and other related protocols at the W3C website and numerous other links at that site.

Next: The web services used in the tutorial >>
 

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Comments On: Calling a Web Service using VB6 with SOAP 3.0

· Web services in one form or another is here to stay. A number of easy to understand...    · The article is good to begin with. Is SOAP a generic solution for communicating...    · What kind of difficulty did you experience. Lots of time it is to do with the data...    · It is possible to call a web service method using VB6 with SOAP 3.0.It is ok if...    · Could you be little more specific? I am not sure what exactly you are trying to...    · Hi, I am facing problem to "Calling Web Services in VB6"If any one already...    · Could be more specific as to what kind of a problem?    · code that can call web service    · Your answer is very brief and I cannot fathom the exact problem you are having.The...    · Does the client server need the MS SOAP Toolkit installing before you can use SOAP...    · I have followed exaactly the same from the tutorial but it prompt an error. The...    · Well, now i roughly know what caused this to happen. It only happen when i am using...    · Hi,is it possible to pass some credential information like user name and...    · Hi Jay,Im getting the follwoing error when trying to use VB 6.0 to access a...    · If you receive this error message try the suggestion below:Connector:Connection...    · how to call a web service created using vb.net.how to use the vb6 application to...    · Hi,You asked me to put clnt.ClientProperty("ServerHTTPRequest") = True before...    · I written following code(in vb 6.0) to call webservice (.net 2.0)Dim strparam ...    · Your code really helped me a lot. Thanks mate. Thanks a lot.   >>> Post your comment now!