Calling webservice (WCF) with Invoke method from MethodInfo class

Question

User-839182035 posted

Hi.

I have a web application without reference to webservice. My application needs connect with any web services. To make this, the application get a list of web services when it need.

To call this web services, we create an instance of MethodInfo class and use the Invoke method like this:

methodInfo.Invoke(instance, BindingFlags.InvokeMethod, null, null, null);

This work fine. The next step would be stop service at any moment. Either a timeuot or a simple button.

var thread = new Thread(() =>
{  
 methodInfo.Invoke(instance, BindingFlags.InvokeMethod, null, null, null);                        
});

thread.Start();

if (!thread.Join(TimeSpan.FromSeconds(60)))
{
  thread.Abort();
  throw new Exception("Timeout - 1 minute");
}

The code above is work fine. The instance parameter contains the name of the web service that I need to connect. However if I verify in database, the process is still running.

Can anyone help me, please?

Thanks

Thiago

Answer 1

User475983607 posted

I have a web application without reference to webservice. My application needs connect with any web services. To make this, the application get a list of web services when it need.

To call this web services, we create an instance of MethodInfo class and use the Invoke method like this:

This approach is simply not possible.  MethodInfo class can only see methods that exist in the current assembly.  If this approach works then there is a service reference or code that calls the service and you should use that code.

Answer 2

User-839182035 posted

Hi.

I don't have the service reference in my application. See the code below:

private void ExecuteWCF(Job job)
        {
            try
            {
                Uri mexAddress = new Uri(job.Caminho);
                MetadataExchangeClientMode mexMode = MetadataExchangeClientMode.HttpGet;

                string contractName = job.Interface;
                string operationName = job.Metodo;

                MetadataExchangeClient mexClient = new MetadataExchangeClient(mexAddress, mexMode);
                mexClient.ResolveMetadataReferences = true;
                mexClient.MaximumResolvedReferences = 200000;
                mexClient.OperationTimeout = new TimeSpan(0, 30, 0);

                MetadataSet metaSet = mexClient.GetMetadata();

                WsdlImporter importer = new WsdlImporter(metaSet);
                Collection<ContractDescription> contracts = importer.ImportAllContracts();
                ServiceEndpointCollection allEndpoints = importer.ImportAllEndpoints();

                ServiceContractGenerator generator = new ServiceContractGenerator();
                var endpointsForContracts = new Dictionary<string, IEnumerable<ServiceEndpoint>>();

                foreach (ContractDescription contract in contracts)
                {
                    generator.GenerateServiceContractType(contract);
                    endpointsForContracts[contract.Name] = allEndpoints.Where(
                        se => se.Contract.Name == contract.Name).ToList();
                }

                if (generator.Errors.Count != 0)
                    throw new Exception("There were errors during code compilation.");

                CodeGeneratorOptions options = new CodeGeneratorOptions();
                options.BracingStyle = "C";
                CodeDomProvider codeDomProvider = CodeDomProvider.CreateProvider("C#");

                CompilerParameters compilerParameters = new CompilerParameters(
                    new string[] { 
                "System.dll", "System.ServiceModel.dll", 
                "System.Runtime.Serialization.dll" });
                compilerParameters.GenerateInMemory = true;

                CompilerResults results = codeDomProvider.CompileAssemblyFromDom(
                    compilerParameters, generator.TargetCompileUnit);

                if (results.Errors.Count > 0)
                {
                    throw new Exception("There were errors during generated code compilation");
                }
                else
                {
                    Type clientProxyType = results.CompiledAssembly.GetTypes().First(
                        t => t.IsClass &&
                            t.GetInterface(contractName) != null &&
                            t.GetInterface(typeof(ICommunicationObject).Name) != null);

                    ServiceEndpoint se = endpointsForContracts[contractName].First();

                    if (job.TipoIntervalo == TipoIntervalo.Hora)
                        se.Binding.SendTimeout = TimeSpan.FromHours(job.TempoEstimado);
                    else if (job.TipoIntervalo == TipoIntervalo.Minuto)
                        se.Binding.SendTimeout = TimeSpan.FromMinutes(job.TempoEstimado);                    
                    
                    se.Binding.ReceiveTimeout = new TimeSpan(0, 10, 0);
                    se.Binding.OpenTimeout = new TimeSpan(0, 10, 0);
                    se.Binding.CloseTimeout = new TimeSpan(0, 10, 0);

                    object instance = results.CompiledAssembly.CreateInstance(
                        clientProxyType.Name,
                        false,
                        System.Reflection.BindingFlags.CreateInstance,
                        null,
                        new object[] { se.Binding, se.Address },
                        CultureInfo.CurrentCulture, null);

                    var methodInfo = instance.GetType().GetMethod(operationName);

                    var thread = new Thread(() =>
                    {
                        Thread.CurrentThread.IsBackground = true;
                        /* run your code here */                        

                        methodInfo.Invoke(instance, BindingFlags.InvokeMethod, null, null, null);                        
                    });

                    thread.Start();

                    if (!thread.Join(TimeSpan.FromSeconds(60)))
                    {
                        thread.Abort();
                        throw new Exception("Timeout - 1 minute");
                    }                    
                }
            }            
            catch (Exception ex)
            {
            }
        }

mexAddress contains the link (wsdl from web service WCF).

After that, the application get all resources to call this web service.

Answer 3

User475983607 posted

I'm not sure if WCF handles an cancellation token, I don't think it does out-of-the-box but there are open source solutions.

https://github.com/max-ieremenko/ServiceModel.Cancellation

https://social.msdn.microsoft.com/Forums/vstudio/en-US/318df640-9a30-4dd4-a13c-1f5b03cbe619/wcf-async-pattern-with-tasks-and-cancellation?forum=wcf