" Live as if you were to die tomorrow. Learn as if you were to live forever.. "
 - Mahatma Gandhi

  1. Home
  2. .Net Development Tips
  3. Tips,Tricks and Traps on Adding Web Reference using Visual Studio 2005 and Visual Studio 2008

Tips,Tricks and Traps on Adding Web Reference using Visual Studio 2005 and Visual Studio 2008

Issue: Severity – Very High
     In one of our windows service, we have been using a web reference for last two years. Just to do some upgrade work, we got the code of this windows service in another machine. Due to some reason we missed that web reference and needed to add again that web service. But very strange!!  We got the below error.
WebServiceReferenceError
What/how does cause this issue/problem?
 
We have done so many experiments. Based on those experiments here are the findings>>
 
Condition 1: “It generally happens to the webservice that require client user to provide credentials.”
 
Condition 2: It is a general happens in Visual Studio 2005, not in Visual Studio 2008.
 
From the Web Service Client Point of View
 
Case 1. Once added one Web Service reference that requires Authentication, when trying to add another Web Service reference that requires Authentication in a single project , it fails simply showing the below error in service description section in the right of the dialog.
 
“Unable to cast COM object of type ‘System.__ComObject’ to interface type ‘EnvDTE.IVsExtensibility’. This operation failed because the QueryInterface call on the COM component for the interface with IID ‘{3C536122-57B1-46DE-AB34-ACC524140093}’ failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).”
 
Case 2. It generally happens to the webservice that requires client user to provide credentials. When trying to refer multiple web services that require authentication in a single project, this is a very common error.
 
 Case 3. Sometimes when retrying to refer the same web service that requires authentication..
 
From Web Service Server Point of View
 
Those web services which have either Integrated Windows Authentication or Digest Authentication settings in IIS will require authentication credentials when trying to add those web service references from Visual Studio. That means when trying to add web service using Visual Studio, it will prompt for Username, Password and Domain credentials, after giving the correct credentials, a proxy will be created.
Solutions:
 
1. Since this problem generally happens in Visual Studio 2005, if possible please use Visual Studio 2008. Please follow below steps to add Web Reference in Visual Studio 2008.
 
Step 1. First Right Click on the Reference and then Click on “Add Service Reference” as shown in image.

AddServiceRef

Step 2. Then this window will be shown

AddServiceWindow

Step 3. Then Click on “Advanced” button as shown below image.

AddServiceWindowClick_1

Step 4. Then below window will be shown and click on “Add Web Reference” as shown in below image.
ServiceADDClick
Step 5. Then same thing as we usually do for adding Web Service Reference.
 
 
2. Instead of directly navigate to the web service’s WSDL page
(xxx.asxm? WSDL), we first view the document page in a web browser and save
the WSDL document into a local xml file (xxx.wsdl) on file disk. Then, we
can add web reference against that local xml file in Visual studio 2005.
 
3. Instead of using Visual Studio 2005 “add web reference” menu, we can use
the .net framework’s wsdl.exe utility to generate the proxy from
command line and there is options that for supplying credentials when the
service require client authentication. e.g.:wsdl.exe  /u: administrator /p: mfs01rk
/out: MindfireProxyClass.cs

http://localhost//MindfireService.asmx?WSDL

Himanshu Sahu , Dot Net Developer, Mindfire Solutions.
Related Tags: MS Visual Studio, NET, Web Referencing
Author : Himanshu Sahu

Leave a Reply