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Visual Studio 2008 Walkthrough: Creating, Hosting and Using WCF Services with Silverlight 2

  • Artigo

Before we Start

The final project is a sample that sends a string to WCF web service from Silverlight and gets a response back. 

Sample source code: https://blogs.msdn.com/nikola/attachment/8168735.ashx (Edit: see comments on how to change the source to work for localhost instead of public web site)

Edit: updated test link: https://www.nokola.com/SampleService/ServiceClientAppTestPage.aspx

This walkthrough is provided as-is, no warranties or rights.

Issues that this post will help you address

This post will help you with deployment, hosting and these 3 kind of common issues in particular:

 

1. The below error may appear when trying to host the web service on the internet.

This collection already contains an address with scheme http. There can be at most one address per scheme in this collection.

Parameter name: item

 

2. Some 500. internal server errors like HTTP Error 500.19 - Internal Server Error. This can happen when you have several web.config files in nested directories (e.g. deploying service in nested folders on the web server)

 

3. UnexpectedHttpResponseCode: With this walkthrough you will not see some of the cross-domain errors that I encountered, like UnexpectedHttpResponseCode. This exception is thrown at the Silverlght client side and can happen either because of cross-domain issues or because the service is throwing exceptions when accessed. If the service works fine, then try adding crossdomain.xml file to the root of your web site, as described here: https://msdn2.microsoft.com/en-us/library/cc197955(VS.95).aspx. Note that two different port numbers on the same server count as two different domains. So you might be getting this error message in case the webservice runs on localhost:12340 and the site is at localhost:12345, for example during debugging.

Creating The Projects

Prerequisites:

· VS 2008

· Silverlight SDK: https://www.microsoft.com/downloads/details.aspx?FamilyId=4E03409A-77F3-413F-B108-1243C243C4FE&displaylang=en

 

Creating the Silverlight project

1. Open Visual Studio 2008

2. Click File, New Project. Select C# (or VB)

3. Click Silverlight and select Silverlight Application, name it ServiceClientApp. I also check Create Directory for Solution. Click OK.

4. Select Generate and HTML test page to host Silverlight within this project. Click OK.

5. Open Page.xaml, and add a text box for typing, a button and a textblock to display the result.

 

Your page.xaml should look something like this:

 

<UserControl x:Class="ServiceClientApp.Page"

   xmlns="https://schemas.microsoft.com/client/2007"

   xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"

   Width="400" Height="300">

    <StackPanel x:Name="LayoutRoot" Background="White">

        <WatermarkedTextBox x:Name="boxTypeText" Watermark="Type a name here"></WatermarkedTextBox>

        <Button Content="Send to WCF web service" Width="200" x:Name="btnSend" Click="btnSend_Click" />

        <TextBlock x:Name="textResponse" Text="Response from WCF Service:"/>

    </StackPanel>

</UserControl>

 

6. In the code-behind file, add the even handler for the button:

 

    public partial class Page : UserControl

    {

        public Page()

        {

            InitializeComponent();

        }

        private void btnSend_Click(object sender, RoutedEventArgs e)

        {

        }

    }

}

 

Creating the service project

1. Right-click on the solution in solution explorer and select Add -> New Web Site

2. Select WCF Service and C# (or VB) for language

3. Name the website HelloWorldService

4. In the App_code folder change in IService.cs and Service.cs the GetData function to accept string instead of int:

public string GetData(string value)

 

5. Add a custom service host factory to Service.cs. We add this since WCF supports one base address only and some web servers return more. If we don’t add this, you may get the following exception when trying to access the web service:

This collection already contains an address with scheme http. There can be at most one address per scheme in this collection.

Parameter name: item

 

Below is how my Service.cs ended up after adding a custom service host and factory. I decided to host the service here: https://www.nokola.com/SampleService/Service.svc

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Runtime.Serialization;

using System.ServiceModel;

using System.Text;

using System.ServiceModel.Activation;

// NOTE: If you change the class name "Service" here, you must also update the reference to "Service" in Web.config and in the associated .svc file.

public class Service : IService

{

      public string GetData(string value)

      {

            return string.Format("You entered: {0}", value);

      }

      public CompositeType GetDataUsingDataContract(CompositeType composite)

      {

            if (composite.BoolValue)

            {

                  composite.StringValue += "Suffix";

            }

            return composite;

      }

}

public class MyServiceHostFactory : ServiceHostFactory

{

    protected override ServiceHost CreateServiceHost(Type serviceType, Uri[] baseAddresses)

    {

        return new CustomServiceHost(serviceType, new Uri("https://nokola.com/SampleService/Service.svc"));

    }

}

public class CustomServiceHost : ServiceHost

{

    public CustomServiceHost(Type serviceType, params Uri[] baseAddresses)

        : base(serviceType, baseAddresses) { }

    protected override void ApplyConfiguration()

    {

        base.ApplyConfiguration();

    }

}

 

6. In Service.svc make use of the factory:

<%@ ServiceHost Language="C#" Debug="true" Service="Service" Factory="MyServiceHostFactory" CodeBehind="~/App_Code/Service.cs" %>

 

7. In web.config update the wsHttpBinding to basicHttpBinding:

<endpoint address="" binding="basicHttpBinding" contract="IService">

 

Deploying and Hosting

 

Deploying the Service

1. Right-click on the HelloWorldService web site project, and select Publish Web Site

2. Select the settings for your web site and click OK. Make sure to publish to the same address as in MyServiceHostFactory that you created. In my case I published at https://nokola.com/SampleService

3. From your web site administration tools select the SampleService fodler to be an application, otherwise you might get something like this:

Server Error in '/' Application.

Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.

 

4. Test the service by opening it in IE. In my case I tested by opening https://nokola.com/SampleService/Service.svc

If you see a page starting like this, then Congratulations! You’ve created your service successfully:

 

Service Service

You have created a service.

 

You probably noted that the title says “Service Service”, this is not because the system is very happy with your new creation (who knows) but also because your service is named “Service”.

 

Deploying the Silverlight Application

Before deploying the application we have to make some more updates so it can access the service correctly:

1. Right-click on the HelloWorldService web site in Solution Explorer and select Add Silverlight Link

2. Select ServiceClientApp (should be already selected), make sure that Add test page that references this control is checked and click Add

3. Build and re-publish the service. Test it again.

4. Try opening the web page from the web site. In my case it’s at https://nokola.com/SampleService/ServiceClientAppTestPage.html

You should see your Silverlight application at that point, and the button does nothing yet

5. Go back to Visual Studio and right-click the ServiceClientApp project in the Solution Explorer. Select Add Service Reference.

6. In the Address box type the address of your service. In my case I typed https://nokola.com/SampleService/Service.svc

7. Update the Page.xaml.cs to call the service. Here’s how I updated mine:

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

namespace ServiceClientApp

{

    public partial class Page : UserControl

    {

        ServiceReference1.ServiceClient client;

        public Page()

        {

            InitializeComponent();

            client = new ServiceClientApp.ServiceReference1.ServiceClient();

            client.GetDataCompleted += new EventHandler<ServiceClientApp.ServiceReference1.GetDataCompletedEventArgs>(client_GetDataCompleted);

        }

        private void btnSend_Click(object sender, RoutedEventArgs e)

        {

            client.GetDataAsync(boxTypeText.Text);

        }

        void client_GetDataCompleted(object sender, ServiceClientApp.ServiceReference1.GetDataCompletedEventArgs e)

        {

            if (e.Error != null)

            {

                textResponse.Text = e.Error.Message;

            }

            else

            {

                textResponse.Text = e.Result;

            }

        }

    }

}

 

8. Rebuild and re-deploy the HelloWorldService web site.

 

Go to your test html (in my case https://nokola.com/SampleService/ServiceClientAppTestPage.html ), type “test” in the box and click Send to WCF web service.

If everything works OK you should see “You entered: test” below the button.

 

Congratulations!

Feedback is always welcome! If you enjoyed this walkthrough and want to see more like this please let me know or leave a comment.

Nikola

ServiceClientApp.zip

Comments

  • Anonymous
    June 02, 2008
    I opened your ServiceClientApp.sln and got the following error whats wrong??  --thanks [UnexpectedHttpResponseCode]

  • Anonymous
    June 03, 2008
    Thank you for pointing out the issue. The service it built to be deployed on a website (www.nokola.com in this case). I made it this way, because it was harder to deploy it on a web site than localhost. To update the source for localhost:

  1. Remove the: Factory="MyServiceHostFactory" text from Service.svc
  2. Recreate ServiceReference1 and point to localhost:  - Right-click and delete the ServiceReference1 from the ServiceClientApp project  - Right-click Service References, select Add Reference, click Discover  - Add the service reference from localhost and name it ServiceReference1 (this is the default name) Build and run, and everything should work! Again, I appreciate the time you spent to raise this issue.

  • Anonymous
    June 08, 2008
    Specification of the Problem A WCF web service works when a user types site in his browser with www in

  • Anonymous
    September 28, 2008
    The comment has been removed

  • Anonymous
    September 29, 2008
    Hi KRUPA, Thank you for reporting this issue! I appreciate your time. We're investigating the issue and I'll get back to you ASAP! I think that issues like this are frustrating - sorry for the inconvenience. Nikola

  • Anonymous
    September 29, 2008
    Hi KRUPA, We investigated the issue you reported. The workaround seems to be to uninstall Blend 2.5 preview and install Blend 2.0. This post outlines the steps: http://silverlight.net/blogs/msnow/archive/2008/09/29/envdte-outputgroup-get-filecount-exception-with-silverlight-2-rc0.aspx Please let me know if this worked for you! Thanks, Nikola

  • Anonymous
    September 29, 2008
    Hi Nikola, I will check & let u know. Thanks for your reply..

  • Anonymous
    September 29, 2008
    i just uninstalled Blend 2.5 preview and installed Blend 2.0. But no use.. still same error occured. Help Me... i dont thik this problem is related with blend. It is related with SilverlightRC0 only..

  • Anonymous
    September 29, 2008
    Could you try these steps:

  1. Uninstall Blend 2.5 June Preview.
  2. Uninstall the Microsoft Silverlight 2 SDK in Add/Remove Programs or Programs and Features
  3. Re-install the Silverlight Tools: http://www.microsoft.com/downloads/details.aspx?FamilyId=c22d6a7b-546f-4407-8ef6-d60c8ee221ed&displaylang=en

  • Anonymous
    September 29, 2008
    btw, I'm trying to intentionally break one machine here and then fix it after reproducing the issue...

  • Anonymous
    September 29, 2008
    done... Thanks for your fast response. Thank again

  • Anonymous
    September 29, 2008
    If I Install Blend on my machine.. That time again this problem raised........ but if i uninstalled blend than silverlight RC0 work properly...

  • Anonymous
    September 30, 2008
    did you install the Blend 2.5 preview or Blend 2.0 + Blend SP1? Blend 2.5 preview does not work with RC0 as far as I know. Blend 2.0 + Blend SP1 should work fine. You can find trial version of Blend 2.0 http://www.microsoft.com/downloads/details.aspx?FamilyId=5FF08106-B9F4-43CD-ABAD-4CC9D9C208D7&displaylang=en Also, if you already have an expired trial of Blend 2, I think the Blend SP will extend it a bit, learn more and install it from here: http://blogs.msdn.com/expression/archive/2008/09/25/expression-blend-2-sp1-preview-released.aspx According to the above blog, you will get the same functionality as Blend 2.5 preview. btw, I really appreciate all the investigation you so, thanks! Hope the above steps (install Blend 2.0 and Blend SP1) will resolve the issue! Note that you have to do the three steps to fix your machine first, as outlined above: uninstall Blend, uninstall SDK, reinstall SLtools. Thanks a lot for your patience! Nikola

  • Anonymous
    May 22, 2009
    The comment has been removed

  • Anonymous
    May 22, 2009
    The remote server returned an error: (415) Cannot process the message because the content type 'application/soap+xml; charset=utf-8' was not the expected type 'text/xml; charset=utf-8'..

  • Anonymous
    May 26, 2009
    Hi Chicka, I think this might solve the problem you're seeing: The service it built to be deployed on a website (www.nokola.com in this case). I made it this way, because it was harder to deploy it on a web site than localhost. To update the source for localhost:

  1. Remove the: Factory="MyServiceHostFactory" text from Service.svc
  2. Recreate ServiceReference1 and point to localhost:
  • Right-click and delete the ServiceReference1 from the ServiceClientApp project
  • Right-click Service References, select Add Reference, click Discover
  • Add the service reference from localhost and name it ServiceReference1 (this is the default name) Build and run, and everything should work! Again, I appreciate the time you spent to raise this issue. Thanks, Nikola