The first time I tried to write a web service client in Visual Studio 2010, my instinct said “create a service reference”. After all, Microsoft loves to tie things in through references. So I did… and I quickly realized I was going to have to create a service reference for each environment if I was going to use the same client for accessing endpoints in multiple environments.

A better way to go is to jump outside Visual Studio and use the command line application wsdl.exe.

wsdl /out:WSProxy.cs http://domain/MyWebService/Endpoint.asmx?WSDL

The stub this lovely little creates has a constructor that directly sets the URL.

public MyWebService()
{
    this.Url = "http://localhost/MyWebService/Endpoint.asmx";
}

Add an override constructor to provide your own URL to make this class more diverse.

public MyWebService(string url)
{
    this.Url = url;
}

Then, get really lazy like me and add a switch based on a command line arg.

if (arg1.Equals("LOCAL"))
    proxy = new WSProxy()

else if (arg1.Equals("QA"))
    proxy = new WSProxy("http://domain/MyWebService/Endpoint.asmx");