[Article] How to run multiple WCF services under one website in IIS 8 where each service is running on separate app-domain

Introduction

    Starting with IIS 7, we can have IIS hosting application which can run on separate App-domain. Running application on separate App-domain is required when we need application to work in isolation i.e. to prevent applications in one application pool from affecting applications in another application pool on the server. An application can have several virtual directories, and each one will be served by the same App-domain as the application to which they belong. In most of the cases it should be fine to run an application in the default app-domain created by IIS. But on special scenarios say for example, if you want your application to be served by a different version of the run-time, then you can create an app-domain by specifying the run-time version and can use that to serve the application. Or if you want your applications to work in complete isolation then also you can do the same. Here in this post we will see how to host multiple WCF service under one website where each service is running in isolation with each on separate app-domain.

Hosting WCF service using separate app-domain.

  An application is an object important to the server at run-time. Every website object in IIS must have an application and every application must have at least one virtual directory where each virtual directory points to a physical directory path. When you create a website object in IIS, you are creating a default application. An application can have several virtual directories. To know how you can host a WCF service in default application in IIS, you can refer to the article [Article] How to host a WCF service in IIS 8. Let us now examine how we have created a website object with default application.

  Here in the IIS, in connections section, on Sites, when we right click and say “Add website” it opens up a website object(default application) creation wizard like as shown in the image above. Here “Site name” refers to the name of the site(application) which you want. “Physical directory” should point to the root directory of the website. Just for the demo purpose we will point the physical directory to an empty folder. It could also be a root folder of one WCF service where you have the .svc file. And in the section where it is asking for the “Application pool” is where we have to select the application pool or so called app-domain. Here at the moment we only have a default app domain so we will leave it as is. And if you say ok, then the website object is ready. Now what we have done here is we have created a website object, we have created a default application, we have created a virtual directory which will point to the physical directory as specified in “Physical directory” and the default application will now run in an app domain specified by us in the “Application pool” section. Now we will see how we can create another app-domain.

Creating Application Pool(App-domain)

In IIS, on the connection section, if you expand the server node, you can see “Application Pool” node. On the “Application Pools” node if you right-click and say “Add Application Pool” it will open up a window as shown below. Give a name for your new app-domain, this could be any unique name. and select the version of run-time which you like the application to run with and say Ok. Now your new app-domain is ready to use. 

Adding new application object

  Now on to the website object which we just created, right click and say Add Application, it opens up a wizard to create an application object under the website object. Now in this wizard, Alias is the name which we are going to give to the application and this name is also going to be the part of the url of the application so give it a proper name. The Physical Path is where your root folder for your wcf service where you have the .svc file. Now the Application pool section is where you can select your App-domain which you created just before.

Now when you browse the .svc file from the application folder, IIS will then use the App-domain which you have assigned for the application to serve the request. In this way you can create more app domain and more WCF services which will then work in isolation.

Read More

[Solved] How to know if the window state has changed to maximized in WPF.

Introduction

    In this post we will see how we can identify if the application has been maximized or it is restored to normal state. We will use the Resize event equivalent in WPF which is SizeChanged event. We will subscribe to this event and will check the window state to identify if the window has been maximized or it is restored to normal.

Application.Current.MainWindow.SizeChanged += WindowSizeChanged;

private void WindowSizeChanged(object sender, SizeChangedEventArgs e)
{
    this.HandleWindowState();
}
 
private void HandleWindowState()
{
    WindowState windowState = Application.Current.MainWindow.WindowState;
    if (windowState == WindowState.Maximized)
     {                    
     }
    else if (windowState == WindowState.Normal)
     {                    
     }            
}

And let’s not forget to clean it by unsubscribing to the SizeChanged event by

Application.Current.MainWindow.SizeChanged -= WindowSizeChanged;

Read More

[Article] How to host a WCF service in IIS 8

 Introduction

  Here in this article we will see how to configure and host a WCF service in IIS 8. When we want to expose our service to internet, hosting it in IIS is the easy and effective way to do it. When you host it in IIS, it comes with all the added advantage of the web server. If you don’t want to host in IIS, you could still do that with a console application running in a server machine. To know more on hosting a service in console application and exposing an http endpoint, you can refer to [Article] How to host a WCF service in console application using wsHttp binding. The entire configuration which you will see in this article will be for Windows 8 and Visual studio 2012.

1. Configure IIS
2. Create a WCF service.
3. Hosting in IIS

1. Configure IIS

• Enable IIS – Internet information service (IIS) will be disabled by default in windows 8. We need to enable this as a first step in hosting wcf. To do this you have to go to Control Panel -> Programs and Features and select Turn windows features on or off from the left side menu and enable IIS.

• Enable Asp.Net – The runtime which is going to serve your wcf service when you host it in IIS is the ASP.Net. By default this is disabled in IIS, we have to enable this. Without ASP.Net IIS will not be able to serve your WCF service. To enable ASP.Net you have to go to Control Panel -> Programs and Features and select Turn windows features on or off and under Internet Information Service->World Wide Web service->Application Development Features select the ASP.Net version which you want.

• Enable WCF and its HTTP endpoint feature – We have to enable WCF and the WCF HTTP Activation feature in IIS. Without this IIS won’t be able to recognize the WCF service and it won’t be able to serve it. To enable this, go to Control Panel -> Programs and Features and select Turn windows features on or off and select .Net Framework 4.5 Advanced Services and enable WCF Services and HTTP Activation under WCF.

With this our basic features in IIS to host a WCF service is enabled. Now restart IIS and we should be able to host the WCF service.

2. Create a WCF service

  Here to test hosting a WCF service, we will create simple WCF service. We will then host this WCF service to see it in action in IIS. To begin with, let’s create a service. Create a folder called Host_wcf. Inside this folder create another folder and name it as App_Code. To this folder, create a file called DataService.cs and copy paste the service code as given below.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace SqliteService
{
    using System.ServiceModel;
    [ServiceContract()]
    public interface IDataService
    {
        [OperationContract()]
        void AddCustomer();

        [OperationContract()]
        void AddProduct();
    }

    public class DataService : IDataService
    {
        public void AddCustomer()
        {
        }

        public void AddProduct()
        {
            throw new NotImplementedException();
        }
    }
}

Now create a file called services.svc in the root folder, i.e. to Host_wcf and add the below line of code into it.

<%@ServiceHost language=c# Debug="true" Service="SqliteService.DataService" CodeBehind="~/App_Code/DataService.cs" %>

Here CodeBehind points to the file where we have the service implementation. Now we need a Web.config file in the root folder i.e. at Host_wcf folder. Copy paste the below line of code into it. Here the configuration is a prebuild configuration, to know more on how to create this end point, go to [Article] How to host a WCF service in console application using wsHttp binding.

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior name="MEX">
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="false" />
        </behavior>
      </serviceBehaviors>
    </behaviors>   
    <services>
      <service behaviorConfiguration="MEX" name="SqliteService.DataService">
        <endpoint address="Mex" binding="wsHttpBinding" bindingConfiguration=""
          name="Mex" contract="IMetadataExchange" kind="" endpointConfiguration="" />
        <endpoint address="IDataService" binding="wsHttpBinding" bindingConfiguration=""
          name="wsHttp" contract="SqliteService.IDataService" />
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:80" />
          </baseAddresses>
        </host>
      </service>
    </services>
  </system.serviceModel>
</configuration>

Now we need to set the permission for the root folder so that IIS can access content from this folder. Go to security settings of the root folder and give read and execute permission for “Everyone”. With this, we are ready with the service. When you host a service in IIS, it is the ASP.Net runtime which compiles the code behind and serve the service. So make sure that it is error free and it can compile properly. Alternatively you can create a WCF project using “WCF Service Application” project template in visual studio and compile the code to make sure that it can compile properly.

3. Hosting in IIS

Now we will see how we can host a service in IIS. Let us launch IIS. To do this type “inetmgr” in Run, it will open up the Internet Information Service (IIS) Manager. Now expand the server from left hand side under Connection section. Now expand Sites. Here we will have a default website running, the default website will be using port no 80. We are also going to host the service on port 80 which is the default http port. We cannot have two websites using same port. So we will stop the default website for time being. To do this, right click on the Default Web Site and from Manage WebSite say stop. Now right click on the Sites and say Add Website and fill in the details as shown in the image below. We can also host our service as an application under the default website but let’s do it this way.

Now here the physical path is the path to our root directory which we created to hold the wcf service files. Say OK and your service should be ready to use now. Now to confirm this, we will browse the .svc file in our service.

If everything is fine, it should pop up a page which looks something like as shown in the image below.

Read More

[Article] How to host a WCF service in console application using wsHttp binding.

Introduction

    In this article we will see how to host a wcf service using the wsHttpBinding. When you use http, you would normally host it in IIS, but if you would like to host it in a console application, you could follow this article. Here we will try to host a service with a wsHttpBinding and will expose a MEX endpoint in order to expose the metadata so that any tool which can generate a proxy can use it. Here in this example we are exposing the MEX endpoint particularly to be used in the WCF test client. This article will not cover how you can generate a wcf service. If you like to know how a basic service is created, you need to read [Article] Creating WCF Service and Self Hosting in a console application.

How to edit wcf configuration.

All your wcf configuration will be stored in the app.conf file of your host project. Here in our case as we are going to host it in a console application, it will be the app.conf of the console application. You could use the wcf configuration edit tool to edit this configuration. To open the wcf configuration tool, do as shown in the image.

Adding an endpoint with wsHttpBinding

Here we need to add an wshttp endpoint. Create your endpoint as shown in the image below.

Here in the address field, give the name of the interface where you have defined a service contract. Here the address name could be anything but we will keep it as the name of the interface, this is the relative address which we are defining; we will later add a base address for this. Add wsHttpBinding on to the binding column. Here we defined wsHttp as the binding for this endpoint. To the contract field, browse to the dll where we have the interface on which we have defined the service contract. You could point to the dll where we have this interface. 

Adding a base address for the endpoint.

Now we need to add a base address to the service, So that the complete address for the service will look like “Base Adress + Name of the service” Add it as shown in the image. Here the port number can be any port number except the reserved and already used.

With this, we are done creating a basic endpoint.

Adding MEX Endpoint.

Now create a wsHttp MEX endpoint as shown in the image. Here IMetadataExchange is the default contract implementation from Microsoft. We will just add this text as the contract implementation of MEX. 

Now this is a MEX end point exposed via http, so we need to enable some more setting for this MEX end point to work. Go to advanced->Service Behavior->MEX and set HttpGetEnabled to true as shown in the image below.

Adding Mex behaviour to the service.

Now we need to enable MEX behaviour to the service. Do as shown in the image. Select MEX from the dropdown for BehaviorConfiguration. Remember, MEX is the name given to the Mex endpoint.

Now we are ready, now remember to run the service host as Admin, because when we have http endpoint, it requires this or else it will throw an access violation exception. Now open the WCF test client and add the service endpoint to test it.

Read More

[Solved] How to show a message box before the application main window is launched.

Introduction

    There are scenarios where we have to show a standalone message box even before the application main window is launched. In such scenario, we need to do something different. Say if we have a composite application with a bootstrapper, and we want to show some error while running a bootstrapper, it may look difficult because we don’t have a parent window. In such scenario, we can show the message box as shown below.

private static void ShowError(string message)
        {
            
/* We cannot show a message out in void. So we are creating a dummy window and setting visibility as hidden. we will then use this as the parent of the message box. */

            var w = new Window() { Height = 0, Width = 0, Visibility = Visibility.Hidden, WindowStyle = WindowStyle.None };

            w.Show();
            System.Windows.MessageBox.Show(w, message);
            w.Close();
        }

Here we will create and show a window where the visibility of the window is set to hidden, now we will use this window as the parent of the message box and will show the message box.

Read More