在网上看到通过这样的方式怎么调用呢

System.Net.WebClient wc = new System.Net.WebClient(); 

  System.IO.Stream stream = wc.OpenRead(url+"?WSDL"); 
 
System.Web.Services.Description.ServiceDescription sd =
System.Web.Services.Description.ServiceDescription.Read(stream); 
 
System.Web.Services.Description.ServiceDescriptionImporter sdi = new
System.Web.Services.Description.ServiceDescriptionImporter(); 
 
sdi.AddServiceDescription(sd,"",""); 
  System.CodeDom.CodeNamespace cn =
new System.CodeDom.CodeNamespace(@namespace); 
 
System.CodeDom.CodeCompileUnit ccu = new System.CodeDom.CodeCompileUnit(); 

  ccu.Namespaces.Add(cn); 
  sdi.Import(cn,ccu); 


请详细说说这种方式是怎么调用的