juanchiy2k juanchiy2k - 10 months ago 75
C# Question

How to call a web service dynamically without add service reference over SSL

I'm developing a client that call a web service without add service reference. The method receives as a parameter an XML.

static void Main(string[] args)
string xmlAux = string.Empty;
string link = "https://test.xxx.com/xxx/xxx.asmx";

string arg1 = @"<tuca> <hd> <t_doc>10</t_doc> <id_user>xxx</id_user> <pwd>xxx</pwd> <id_pais>xxx</id_pais> </hd> <parametros> <par tipo=""tipo_sujeto"">fisico</par> <par tipo=""calificacion"">xxx</par> <par tipo=""CEDULA DE IDENTIDAD"">xxx</par> </parametros> </tuca>";

object[] arguments = { arg1 };

var ws = CallWebService(link, "xxx", "Reporte", arguments);

if (ws != null)
xmlAux = ws.ToString();
[System.Security.Permissions.SecurityPermissionAttribute(System.Security.Permissions.SecurityAction.Demand, Unrestricted = true)]
internal static object CallWebService(string webServiceAsmxUrl, string serviceName, string methodName, object[] args)
System.Net.WebClient client = new System.Net.WebClient();

// Connect To the web service
System.IO.Stream stream = client.OpenRead(webServiceAsmxUrl + "?wsdl");

// Now read the WSDL file describing a service.
var description = System.Web.Services.Description.ServiceDescription.Read(stream);

///// LOAD THE DOM /////////
// Initialize a service description importer.
var importer = new System.Web.Services.Description.ServiceDescriptionImporter();

importer.ProtocolName = "Soap12"; // Use SOAP 1.2.

importer.AddServiceDescription(description, null, null);

// Generate a proxy client.
importer.Style = System.Web.Services.Description.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.
var nmspace = new System.CodeDom.CodeNamespace();

var unit1 = new System.CodeDom.CodeCompileUnit();

// Import the service into the Code-DOM tree. This creates proxy code that uses the service.
var warning = importer.Import(nmspace, unit1);

if (warning == 0) // If zero then we are good to go
// Generate the proxy code
var provider1 = System.CodeDom.Compiler.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" };

var parms = new System.CodeDom.Compiler.CompilerParameters(assemblyReferences);

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

// Check For Errors
if (results.Errors.Count > 0)
foreach (System.CodeDom.Compiler.CompilerError oops in results.Errors)
System.Diagnostics.Debug.WriteLine("========Compiler error============");

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


// Finally, Invoke the web service method
object wsvcClass = results.CompiledAssembly.CreateInstance(serviceName);

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

return mi.Invoke(wsvcClass, args);


return null;


In the line:

return mi.Invoke(wsvcClass, args)

throws exception:

InnerException: {"The underlying connection was closed: An unexpected error occurred on a receive."}

Message: Exception has been thrown by the target of an invocation.

Answer Source

I solved it with this post:

Invoking a Web Service dynamically using System.Net and SOAP