How to: Create a Basic WCF Web HTTP Service - WCF (2024)

Windows Communication Foundation (WCF) allows you to create a service that exposes a Web endpoint. Web endpoints send data by XML or JSON, there is no SOAP envelope. This topic demonstrates how to expose such an endpoint.

To create a Web endpoint

1. Define a service contract using an interface marked with the ServiceContractAttribute, WebInvokeAttribute and the WebGetAttribute attributes.

   [ServiceContract]public interface IService{ [OperationContract] [WebGet] string EchoWithGet(string s); [OperationContract] [WebInvoke] string EchoWithPost(string s);}

   <ServiceContract()> _Public Interface IService <OperationContract()> _ <WebGet()> _ Function EchoWithGet(ByVal s As String) As String <OperationContract()> _ <WebInvoke()> _ Function EchoWithPost(ByVal s As String) As Stringend interface

   Note

   By default, WebInvokeAttribute maps POST calls to the operation. You can, however, specify the HTTP method (for example, HEAD, PUT, or DELETE) to map to the operation by specifying a "method=" parameter. WebGetAttribute does not have a "method=" parameter and only maps GET calls to the service operation.

2. Implement the service contract.

   public class Service : IService{ public string EchoWithGet(string s) { return "You said " + s; } public string EchoWithPost(string s) { return "You said " + s; }}

   Public Class Service Implements IService Public Function EchoWithGet(ByVal s As String) As String Implements IService.EchoWithGet Return "You said " + s End Function Public Function EchoWithPost(ByVal s As String) As String Implements IService.EchoWithPost Return "You said " + s End FunctionEnd Class

To host the service

1. Create a WebServiceHost object.

   WebServiceHost host = new WebServiceHost(typeof(Service), new Uri("http://localhost:8000/"));

   Dim host As WebServiceHost = New WebServiceHost(GetType(Service), New Uri("http://localhost:8000/"))

2. Add a ServiceEndpoint with the WebHttpBehavior.

   ServiceEndpoint ep = host.AddServiceEndpoint(typeof(IService), new WebHttpBinding(), "");

   Dim ep As ServiceEndpoint = host.AddServiceEndpoint(GetType(IService), New WebHttpBinding(), "")

   Note

   If you do not add an endpoint, WebServiceHost automatically creates a default endpoint. WebServiceHost also adds WebHttpBehavior and disables the HTTP Help page and the Web Services Description Language (WSDL) GET functionality so the metadata endpoint does not interfere with the default HTTP endpoint.

   Adding a non-SOAP endpoint with a URL of "" causes unexpected behavior when an attempt is made to call an operation on the endpoint. The reason for this is the listen URI of the endpoint is the same as the URI for the help page (the page that is displayed when you browse to the base address of a WCF service).

   You can do one of the following actions to prevent this from happening:

   • Always specify a non-blank URI for a non-SOAP endpoint.
   • Turn off the help page. This can be done with the following code:

   ServiceDebugBehavior sdb = host.Description.Behaviors.Find<ServiceDebugBehavior>();sdb.HttpHelpPageEnabled = false;

   Dim sdb As ServiceDebugBehavior = host.Description.Behaviors.Find(Of ServiceDebugBehavior)()sdb.HttpHelpPageEnabled = False

3. Open the service host and wait until the user presses ENTER.

   host.Open();Console.WriteLine("Service is running");Console.WriteLine("Press enter to quit...");Console.ReadLine();host.Close();

   host.Open()Console.WriteLine("Service is running")Console.WriteLine("Press enter to quit...")Console.ReadLine()host.Close()

   This sample demonstrates how to host a Web-Style service with a console application. You can also host such a service within IIS. To do this, specify the WebServiceHostFactory class in a .svc file as the following code demonstrates.

   <%ServiceHost language=c# Debug="true" Service="Microsoft.Samples.Service" Factory=System.ServiceModel.Activation.WebServiceHostFactory%>

To call service operations mapped to GET in a browser

1. Open a web browser, enter the URL "http://localhost:8000/EchoWithGet?s=Hello, world!", and then press Enter. The URL contains the base address of the service (http://localhost:8000/), the relative address of the endpoint (""), the service operation to call ("EchoWithGet"), and a question mark followed by a list of named parameters separated by an ampersand (&).

To call service operations in code

1. Create an instance of ChannelFactory<TChannel> within a using block.

   using (ChannelFactory<IService> cf = new ChannelFactory<IService>(new WebHttpBinding(), "http://localhost:8000"))

   Using cf As New ChannelFactory(Of IService)(New WebHttpBinding(), "http://localhost:8000")

2. Add WebHttpBehavior to the endpoint the ChannelFactory<TChannel> calls.

   cf.Endpoint.Behaviors.Add(new WebHttpBehavior());

   cf.Endpoint.Behaviors.Add(New WebHttpBehavior())

3. Create the channel and call the service.

   IService channel = cf.CreateChannel();string s;Console.WriteLine("Calling EchoWithGet via HTTP GET: ");s = channel.EchoWithGet("Hello, world");Console.WriteLine(" Output: {0}", s);Console.WriteLine("");Console.WriteLine("This can also be accomplished by navigating to");Console.WriteLine("http://localhost:8000/EchoWithGet?s=Hello, world!");Console.WriteLine("in a web browser while this sample is running.");Console.WriteLine("");Console.WriteLine("Calling EchoWithPost via HTTP POST: ");s = channel.EchoWithPost("Hello, world");Console.WriteLine(" Output: {0}", s);

   Dim channel As IService = cf.CreateChannel()Dim s As StringConsole.WriteLine("Calling EchoWithGet via HTTP GET: ")s = channel.EchoWithGet("Hello, world")Console.WriteLine(" Output: {0}", s)Console.WriteLine("")Console.WriteLine("This can also be accomplished by navigating to")Console.WriteLine("http://localhost:8000/EchoWithGet?s=Hello, world!")Console.WriteLine("in a web browser while this sample is running.")Console.WriteLine("")Console.WriteLine("Calling EchoWithPost via HTTP POST: ")s = channel.EchoWithPost("Hello, world")Console.WriteLine(" Output: {0}", s)

4. Close the WebServiceHost.

   host.Close();

   host.Close()

Example

The following is the full code listing for this example.

// Service.csusing System;using System.Collections.Generic;using System.ServiceModel;using System.ServiceModel.Description;using System.ServiceModel.Web;using System.Text;namespace Microsoft.ServiceModel.Samples.BasicWebProgramming{ [ServiceContract] public interface IService { [OperationContract] [WebGet] string EchoWithGet(string s); [OperationContract] [WebInvoke] string EchoWithPost(string s); } public class Service : IService { public string EchoWithGet(string s) { return "You said " + s; } public string EchoWithPost(string s) { return "You said " + s; } } class Program { static void Main(string[] args) { WebServiceHost host = new WebServiceHost(typeof(Service), new Uri("http://localhost:8000/")); try { ServiceEndpoint ep = host.AddServiceEndpoint(typeof(IService), new WebHttpBinding(), ""); host.Open(); using (ChannelFactory<IService> cf = new ChannelFactory<IService>(new WebHttpBinding(), "http://localhost:8000")) { cf.Endpoint.Behaviors.Add(new WebHttpBehavior()); IService channel = cf.CreateChannel(); string s; Console.WriteLine("Calling EchoWithGet via HTTP GET: "); s = channel.EchoWithGet("Hello, world"); Console.WriteLine(" Output: {0}", s); Console.WriteLine(""); Console.WriteLine("This can also be accomplished by navigating to"); Console.WriteLine("http://localhost:8000/EchoWithGet?s=Hello, world!"); Console.WriteLine("in a web browser while this sample is running."); Console.WriteLine(""); Console.WriteLine("Calling EchoWithPost via HTTP POST: "); s = channel.EchoWithPost("Hello, world"); Console.WriteLine(" Output: {0}", s); Console.WriteLine(""); } Console.WriteLine("Press <ENTER> to terminate"); Console.ReadLine(); host.Close(); } catch (CommunicationException cex) { Console.WriteLine("An exception occurred: {0}", cex.Message); host.Abort(); } } }}

'Service.csImports System.Collections.GenericImports System.ServiceModelImports System.ServiceModel.DescriptionImports System.ServiceModel.WebImports System.Text<ServiceContract()> _Public Interface IService <OperationContract()> _ <WebGet()> _ Function EchoWithGet(ByVal s As String) As String <OperationContract()> _ <WebInvoke()> _ Function EchoWithPost(ByVal s As String) As Stringend interfacePublic Class Service Implements IService Public Function EchoWithGet(ByVal s As String) As String Implements IService.EchoWithGet Return "You said " + s End Function Public Function EchoWithPost(ByVal s As String) As String Implements IService.EchoWithPost Return "You said " + s End FunctionEnd ClassModule program Sub Main() Dim host As WebServiceHost = New WebServiceHost(GetType(Service), New Uri("http://localhost:8000/")) Try Dim ep As ServiceEndpoint = host.AddServiceEndpoint(GetType(IService), New WebHttpBinding(), "") host.Open() Using cf As New ChannelFactory(Of IService)(New WebHttpBinding(), "http://localhost:8000") cf.Endpoint.Behaviors.Add(New WebHttpBehavior()) Dim channel As IService = cf.CreateChannel() Dim s As String Console.WriteLine("Calling EchoWithGet via HTTP GET: ") s = channel.EchoWithGet("Hello, world") Console.WriteLine(" Output: {0}", s) Console.WriteLine("") Console.WriteLine("This can also be accomplished by navigating to") Console.WriteLine("http://localhost:8000/EchoWithGet?s=Hello, world!") Console.WriteLine("in a web browser while this sample is running.") Console.WriteLine("") Console.WriteLine("Calling EchoWithPost via HTTP POST: ") s = channel.EchoWithPost("Hello, world") Console.WriteLine(" Output: {0}", s) Console.WriteLine("") End Using Console.WriteLine("Press <ENTER> to terminate") Console.ReadLine() host.Close() Catch cex As CommunicationException Console.WriteLine("An exception occurred: {0}", cex.Message) host.Abort() End Try End SubEnd Module

Compiling the code

When compiling Service.cs reference System.ServiceModel.dll and System.ServiceModel.Web.dll.

See also

• WebHttpBinding
• WebGetAttribute
• WebInvokeAttribute
• WebServiceHost
• WebHttpBehavior
• WCF Web HTTP Programming Model