动态添加Web参考C＃

Question

My code is this:

internal class WsProxy
{

    [SecurityPermissionAttribute(SecurityAction.Demand, Unrestricted = true)]
    internal static object CallWebService(string webServiceAsmxUrl, string userName, string password, string serviceName, string methodName, object[] args) 
    {

        System.Net.WebClient client = new System.Net.WebClient();
        if (userName.Length > 0)
        {
            client.Credentials = new NetworkCredential(userName, password);
        } 
        // Connect To the web service

        System.IO.Stream stream = client.OpenRead(webServiceAsmxUrl + "?wsdl");

        // Now read the WSDL file describing a service.

        ServiceDescription description = ServiceDescription.Read(stream);

        ///// LOAD THE DOM /////////

        // Initialize a service description importer.

        ServiceDescriptionImporter importer = new ServiceDescriptionImporter();

        importer.ProtocolName = "Soap"; // Use SOAP 1.2.

        importer.AddServiceDescription(description, null, null);

        // Generate a proxy client.

        importer.Style = ServiceDescriptionImportStyle.Client;

        // Generate properties to represent primitive values.

        importer.CodeGenerationOptions = System.Xml.Serialization.CodeGenerationOptions.GenerateProperties;

        // Initialize a Code-DOM tree into which we will import the service.

        CodeNamespace nmspace = new CodeNamespace();

        CodeCompileUnit unit1 = new CodeCompileUnit();

        unit1.Namespaces.Add(nmspace);

        // Import the service into the Code-DOM tree. This creates proxy code that uses the service.

        ServiceDescriptionImportWarnings warning = importer.Import(nmspace, unit1);

        if (warning == 0) // If zero then we are good to go
        {

            // Generate the proxy code

            CodeDomProvider provider1 = CodeDomProvider.CreateProvider("CSharp");

            // Compile the assembly proxy with the appropriate references

            string[] assemblyReferences = new string[5] { "System.dll", "System.Web.Services.dll", "System.Web.dll", "System.Xml.dll", "System.Data.dll" };

            CompilerParameters parms = new CompilerParameters(assemblyReferences);

            CompilerResults results = provider1.CompileAssemblyFromDom(parms, unit1);

            // Check For Errors

            if (results.Errors.Count > 0)
            {

                foreach (CompilerError oops in results.Errors)
                {

                    System.Diagnostics.Debug.WriteLine("========Compiler error============");

                    System.Diagnostics.Debug.WriteLine(oops.ErrorText);

                }

                throw new System.Exception("Compile Error Occured calling webservice. Check Debug ouput window.");

            }

            // Finally, Invoke the web service method

            object wsvcClass = results.CompiledAssembly.CreateInstance("nmspace");//nmspace

            MethodInfo mi = wsvcClass.GetType().GetMethod(methodName);

            return mi.Invoke(wsvcClass, args);

        }

        else
        {

            return null;

        }

    }

And here is how I call it:

object[] arg = new object[5];
WsProxy.CallWebService(@"myurl/somename.asmx", "NameService", "TheMethod", arg); 

But every time, wsvcClass is null.

I tried changing

object wsvcClass = results.CompiledAssembly.CreateInstance("nmspace");

to

object wsvcClass = results.CompiledAssembly.CreateInstance("nmspace."+serviceName);

and it doesn't work.

Everyone says that the code works like charm, but I can't get it to work. Why?

UPDATE: Here is what I do when I add the reference dynamically:

Namespace.MyService defect = new Namespace.MyService();
defect.Name = "someName";

And here is how I try to do it via code:

object wsvcClass = results.CompiledAssembly.CreateInstance("Namespace." + "MyService");
MethodInfo mi = wsvcClass.GetType().GetMethod("Namespace." + "MyService");
return mi.Invoke(null, new object[] { "someName" });

mi is null and I know there's something wrong on the last line too. It just looks stupid to me.

Answer 1

have you tried

object wsvcClass = results.CompiledAssembly.CreateInstance(serviceName);

"nmspace" is wrong as this is the name of your variable, which holds a CodeNamespace with no name.