WCF using C#: Building your first WCF application

Basic Concepts

The WCF system contains:

Client application
Service .svc (Server application)
Interface - where the clients connects usually the interface is called something like Ixyz.WCF.Project if the project is called xyz.WCF.Project
Bindings - describe the endpoints and protocols used
Proxies - hide the serialization details from the clients

Build a simple WCF app

First: Create a console application

New project > Console Application

Name it “ProductService” but change the SolutionName to “Products”

What you should get:

Right click on Products (the solution) > Add > New project > Console Application > ConsoleAplication and name it ProductsClient

Next, add a new project of type ClassLibrary called ProductInterfaces

The result:

Git repository created - files saved

https://github.com/pkirklewski/SimpleWCF-Tutorial

Right click on the ProductService > Add > New item > Data > ADO .NET Entity Data Model

Name the new item: ProductsModel

Generate from database

Create a new connection pointing to your database

Select the Products database

Test the connection

The Wizard created the connection and the connection string

Choose Entity Framework 6.x

Pick the table

Right click on the ProductService > Add > New Item > Click on Vicual C# Items > WCF Service

Name the WCF Service: WCFProductService.cs

WCFProductService created

This is the service contract, it implements the WCFProductService (notice the colon)

WCFProductService contains [ServiceContract] attribute and the [OperationContract] attribute - which is the operation that the client can perform

The [OperationContract] attribute is the
IWCFProductService.cs is the implementation of your service, we want to move it to the ProductInterfaces project so the client can have access to it
Drag and drop the IWCFProductService from the IWCFProductService.cs to ProductInterfaces project

You need to delete it from the “server” (the ProductService since it has just been copied)

Since you have moved the IWCFProductService to a different namespace, you need to change that in IWCFProductService to ProductInterfaces

Add System.ServiceModel (where the WCF model lives) to references of the ProductInterfaces project

Add reference to ProductInterfaces

Remove void DoWork() in the IWCFProductService

Replace it with List<string> ListProducts();

Now we need to implement the above. In the WCFProductService remove the following:

Right click on IWCFProductService and click on the Implement Interface

Result

Now - we need to host the service - in order to do that we need to edit ProductService \ Program.cs and create our host inside of the Main method

Add System.ServiceModel to the ProductService project

using System.ServiceModel;

Inside the Main method, add the following

using(ServiceHost host = new ServiceHost(typeof(WCFProductService)));

using (ServiceHost host = new ServiceHost(typeof(WCFProductService)))

{

host.Open();

Console.WriteLine("Server is open");

Console.WriteLine("<Press Enter to close the server>");

Console.ReadLine("");

}

The host has been created, it will open, write two lines and wait for the user to close it by pressing Enter
The question now is: how will the host, know it’s contract. How it will know the address, the binding the protocol etc. - We need to set up this information and we will store this information in the file called App.config

Double click on the App.config, select the entire <system.serviceModel> tag and delete it:

Right click on the App.config and select Edit WCF Configuration

This will open the Microsoft Service Configuration Editor

Click on Create a New Service

For the Service Type, select ProductService.exe in the productservice\bin\Debug directory

So our service type = ProductService.WCFProductService
Click Next
What service contract are you using ? ProductService.IWCFProductService

Click Next
Leave the HTTP option selected and click Next

Leave the Basic Web Services interoperability checked and click Next

Specify the address for the endpoint:

Press Next and Finish

You should now see all the information Under Endpoints in the Microsoft Service Configuration Editor

We can give the endpoint a name: ProductServiceEndPoint

Go to File > Save and File > Exit

Visual Studio will notice that the files have been changed and will give you a warning messages to which you should respond: Yes to All

The App.config gets updated

Now we will configure the client, click on the App.config in ProductClient

Right click on App.config

Click on Create a New Client

Select Manually and hit Next

Navigate to c:\tutorials\lessons\products\ProductInterfaces\bin\Debug

Click Next

HTTP

Basic Web Services interoperability

The Address of the endpoint should be the same as last time: http://127.0.0.1:7777/ProductService

Name - leave (Default)

You will get the summary

Name the Client Endpoint: ProductServiceEndpoint

Go to File > Save and File > Exit
You should get a warning window - click on Yes to All

Your App.config should get updated

To get the ProductInterface.IWCFProductService - you need to make sure that the namespace in IWCFProductService.cs has been changed to namespace ProductInterfaces also the using System.ServiceModel; needs to be added:

The code of the IWCFProductService.cs at the moment

using System;

using System.Collections.Generic;

using System.Linq;

using System.Runtime.Serialization;

using System.ServiceModel;

using System.Text;

using System.ServiceModel;

namespace ProductInterfaces

{

// NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IWCFProductService" in both code and config file together.

[ServiceContract]

public interface IWCFProductService

{

[OperationContract]

List<string> ListProducts();

}

Without the above - you may get a problem getting the right contract (in my case it was still contract="ProductService.IWCFProductService" instead of ProductInterfaces)

Let’s write an implementation of the ListProducts()
Open the WCFProductService

Erase: throw new NotImplementedException();

Inside the curly brackets add the following:

List<string> productList = new List<string>();

Type try and double click the tab button to get the try catch block

try

{

}

catch (Exception)

{

throw;

}

Inside the try catch block type using > bracket and start typing prod - you should get a list of options - you should select the ProductEntities

using (ProductsEntities database = new ProductsEntities())

The final code of public List<string> ListProducts()

public List<string> ListProducts()

{

Console.WriteLine("ListProducts() has been called by the client");

List<string> productList = new List<string>();

try

{

using (ProductsEntities database = new ProductsEntities())

{

var products = from p in database.Products select p.ProductID.ToString();

productList = products.ToList();

}

catch (Exception)

{

throw;

}

return productList;

}

Now - move over to the ProductClient

Add reference to System.ServiceModel

Now we need to create the channel factory, basically we need to create our proxy which will take care of the connection to the service as vell as it handles the serialization behind the scenes
Add the using System.ServiceModel; - preprocessor directive (for some reason just adding the reference doesn’t bring the ChannelFactory references untill you explicitly add the using System.ServiceModel preprocessor directive)

Add a reference to ProductInterfaces

Add using ProductInterfaces; preprocessor directive (just adding a reference does not work for me)

Type:

ChannelFactory<IWCFProductService> channelFactory = new ChannelFactory<IWCFProductService>(“”);

Add the name of the endpoint from App.config as the parameter

Result

ChannelFactory<IWCFProductService> channelFactory = new ChannelFactory<IWCFProductService>("ProductServiceEndpoint");

Create a channel

IWCFProductService proxy = channelFactory.CreateChannel();

Now you should be able to see what the service offers

The final code of the ProductsClient.Program.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.ServiceModel;

using ProductInterfaces;

namespace ProductsClient

{

class Program

{

static void Main(string[] args)

{

ChannelFactory<IWCFProductService> channelFactory = new ChannelFactory<IWCFProductService>("ProductServiceEndpoint");

IWCFProductService proxy = channelFactory.CreateChannel();

//calls the server

List<string> products = proxy.ListProducts();

foreach (var p in products)

{

Console.WriteLine(p);

}

Console.ReadLine();

}

The above code, calls the service it will extract the product list and return it to the client printing the results in the console - you can install the client on any machine in the world, it will connect to the given IP of your ProductService and get the data

Now - right click on your Solution go to Preferences and set the Startup Project to Multiple startup projects - ProductInterfaces - None, ProductClient Start, ProductService Start