WCF: There was no endpoint listening at, that could accept the message

Question

I have WCF Service (JSON), and ASP.NET website that we add a service reference to that site connected to the wcf service.

when i test the service using POSTMAN and S

Answer 1

When we invoke the service which created with WebHttpBinding via client proxy class, there may be some differences from other bindings. We need to configure the client configuration manually, such as adding the endpoint behavior to service endpoint and webget/webinvoke attribute to the automatically generated operation method by adding service reference.
I have made a demo, wish it is useful to you.
Server end (console application).

class Program
    {
        static void Main(string[] args)
        {
            using (ServiceHost sh=new ServiceHost(typeof(MyService)))
            {
                sh.Opened += delegate
                {
                    Console.WriteLine("Service is ready......");
                };
                sh.Closed += delegate
                {
                    Console.WriteLine("Service is closed");
                };
                sh.Open();
                Console.ReadLine();
                sh.Close();

            }
        }
    }
    [ServiceContract]
    public interface IService
    {
        [OperationContract]
        [WebGet]
        string SayHello();
    }
    public class MyService : IService
    {
        public string SayHello()
        {
return "Hello, Busy world";        }
}

App.config

Client(console app)

static void Main(string[] args)
{
    ServiceReference1.ServiceClient client = new ServiceReference1.ServiceClient();
    try
    {
        Console.WriteLine(client.SayHello());
    }
    catch (Exception)
    {

        throw;
    }

}

App.config

We also need to add the WebGet attribute to the operation method.

[System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "4.0.0.0")]    [System.ServiceModel.ServiceContractAttribute(ConfigurationName="ServiceReference1.IService")]
public interface IService {
            [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/IService/SayHello", ReplyAction="http://tempuri.org/IService/SayHelloResponse")]
    [WebGet]
    string SayHello();

Result.

Feel free to let me know if there is anything I can help with.