Author Archives: bjornkuiper - Page 2

WCF RIA gzip compression of response

I was trying to enable gzip compression of my WCF RIA traffic to decrease the amount of data that is send between the client and server and improve performance.

Note: I used Fiddler2 to determine if the responses were actually compressed or not.

There is a lot of Q&A about this topic on the web, but nobody had a straight solution for me. Some posts refered to old versions of IIS or used 3rd party modules.

I was looking for a solution that will work from with IIS7.5 without installing any 3rd party modules.

Here is how I made it work.

Lets first install the necessary modules: the Dynamic and Static Content Compression modules:

How-to enable GZIP compression for normal traffic:
On Windows 7:
“Start->Control Panel->Programs and features” and click on “Turn Windows features on or off”.
Then enable:
“Dynamic Content Compression” and “Static Content Compression” in “Internet Information Services->World Wide Webservices->Performance Features” and press “Ok”.

Now your ‘normal’ HTTP responses are automatically compressed, but your WCF RIA traffic is not.

To enable this we will need to add the mime-type of our WCF RIA traffic to the list of mime-types that need to be compressed. On my system the mime-type for my WCF RIA traffic is application/msbin1. I assume this is the same for everybody.

How-to enable GZIP compression for WCF RIA Services traffic:
Open a command box (cmd.exe)
Navigate to C:\Windows\system32\Inetsrv\ and execute the following command to add the application/msbin1 mime-type to the list of types that needs to be compressed:

appcmd.exe set config -section:system.webServer/httpCompression /+”dynamicTypes.[mimeType=’application/msbin1′,enabled=’True’]” /commit:apphost

This will add an entry into the Windows\System32\Inetsrv\Config\applicationHost.config file.

Now restart your IIS server and compression is enabled for the WCF RIA Services.


HTTP/1.1 200 OK
Cache-Control: no-cache
Pragma: no-cache
Content-Length: 583
Content-Type: application/msbin1
Expires: -1
Server: Microsoft-IIS/7.5
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Thu, 11 Aug 2011 17:47:10 GMT


HTTP/1.1 200 OK
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/msbin1
Content-Encoding: gzip
Expires: -1
Vary: Accept-Encoding
Server: Microsoft-IIS/7.5
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Thu, 11 Aug 2011 17:48:01 GMT
Content-Length: 336

I hope this post was helpful!

Useful link:

WP7: PhoneApplicationService.Current.State made easy

UPDATE 7 NOV 2011: Have a look at this post: WP7: Northern Lights WP7 Toolkit v0.0.1 for the latest version of this code example.

I was reading “Programming Windows Phone 7”, a free Microsoft book (as PDF) from Charles Petzold and came across some code on why and how to access the PhoneApplicationService.Current.State (chapter 6, “Page State” paragraph) and thought about writing the following code to improve the usability.
Hope you like it:

    public class StateManager
        private static PhoneApplicationService appService = PhoneApplicationService.Current;

        public static void Set<T>(string name, T value)
            appService.State[name] = value;

        public static T Get<T>(string name)
            T result = default(T);

            if (appService.State.ContainsKey(name))
                result = (T)appService.State[name];

            return result;

It can then be invoked as follows:

Set a value

StateManager.Set<MyObject>("MyApplicationObject", obj);

Get a value

MyObject obj = StateManager.Get<MyObject>("MyApplicationObject");

Hope you like it.

ArcSDE 10: DBMS table not found [*********][STATE_ID=0]

I recently bumped into a problem when moving my development ArcSDE Geodatabase to another machine. The ArcSDE Geodatabase is running on MS SQL Standard* and is using schema’s to store data for different projects.

After restoring the database on the new machine and trying to access it in ArcCatalog I got the following error message:

DBMS table not found [*********][STATE_ID=0]

This lead me to ArcGIS bug report NIM059178 / Article ID: 38048.

Which has a patch attached, but this patch only solved the connectivity within ArcCatalog and didn’t solve the problem when accessing the ArcSDE from my Python scripts (through the ArcGIS REST Services).

After some digging around I discovered that I didn’t install ArcSDE Service Pack 1 yet. Bug NIM059178 is also part of this Service Pack. Shame on me!

I also took the opportunity to install ArcSDE Service Pack 2, but this SP isn’t necessary to solve this specific issue.

All the different ArcGIS packages (Desktop, Services, etc) have a copy of SP1 and SP2 available and as always, it’s wise to update. You can use Patch Finder to check which version you are currently running – available at the bottom of this link.

I hope this post is helpful for somebody that is encountering the same issue..

*) You need MS SQL Standard or better to use Schemas with ArcSDE Geodatabase. MS SQL Express doesn’t support this with ArcSDE.

Tips & Tricks: Remote Desktop (Terminal) Services on Windows 7

This article describes how to setup the “Remote Desktop Services” – in the past also known as Terminal Services – on Windows 7 using the Microsoft Management Console.

First you need to install the following package:
Remote Server Administration Tools for Windows 7 with Service Pack 1 (SP1)

After installation, navigate to “Control Panel”-“Program and Features” and click on “Turn Windows features on or off”.

Enable “Remote Desktop Services Tools” under “Remote Server Administration Tools”-“Role Administration Tools”.

Role Administration Tools in 'Windows features'

Now you can access the Remote Desktop service through the Microsoft Management Console.

The Microsoft Management Console can be accessed by executing “mmc” in the “Start”-“Run” window.

Go to “File-Add/Remove Snap-in” and Add the “Remote Desktops” snap-in. Now save your MMC configuration settings to the Desktop or any other easy accessible location and your are set.

You can add as many Remote desktops as you want:

MMC screenshot

My experience is that you can get the most out of it by saving your credentials for each connection. This way you can easily connect with each machine and make switching from one machine to another look seamlessly easy and smooth, even when you didn’t log-in yet.

On certain machines saving of credentials is forbidden. You can change this by editing the Group Policies.

Start the Group Policy Editor by running “gpedit.msc”.
Navigate to “Computer Configuration”-“Administrative Templates”-“System”-“Credentials Delegation” and open “Allow Saved Credentials with NTLM-only Server Authentication”.

Enable the policy and click on the Show button to add the machines you want to enable saving of credentials for.

‘TERMSRV/*’ will allow it for any machine (through terminal services). But you can also specify a specific domain, for instance ‘TERMSRV/*’.

Close the screens by clicking “Ok” and you are done!

Happy remote administrating!

Thanks to Alin Constantin for his blog post on how to enable saving of credentials for terminal services.

Tips & Tricks: Listening to Dependency Property change notifications of a given Element


I want to share this great post from Anoop that shows a easy way to add a notification system to dependency properties of a given element. It creates and attaches a new property to the existing property and let’s you specify the PropertyChangedCallback eventhandler.

There are different examples on the internet, but i like how Anoop created a generic method with access to the callback event handler.

Here is the main part of the code:

        /// Listen for change of the dependency property
        public void RegisterForNotification(string propertyName, FrameworkElement element, PropertyChangedCallback callback)
            //Bind to a depedency property
            Binding b = new Binding(propertyName) { Source = element };
            var prop = System.Windows.DependencyProperty.RegisterAttached(
                new System.Windows.PropertyMetadata(callback));

            element.SetBinding(prop, b);

And here is an example on how to use it:

//Shows a message box when the text of the Textbox changes.
	("Text", this.txtMain,(d,e)=>MessageBox.Show("Text changed"));

Read Anoop’s complete article for more information!

update (07/28/2011):
here is small update of the code so it also works with other objects instead of just FrameworkElements

        private void RegisterForNotification(string propertyName, object source, PropertyChangedCallback callback)
            Binding b = new Binding(propertyName);
            b.Source = source;

            DependencyProperty prop = System.Windows.DependencyProperty.RegisterAttached(
                "ListenAttached" + propertyName,
                new System.Windows.PropertyMetadata(callback));

            BindingOperations.SetBinding(this, prop, b);

Tips & Tricks: FieldExists for ArcGIS 10 Python

Here is a way to check if a Field in a feature class already exists or not. I was looking for an existing ArcGIS Esri function / tool but couldn’t find one so I wrote my own.

def FieldExist(featureclass, fieldname):
    fieldList = arcpy.ListFields(featureclass, fieldname)

    fieldCount = len(fieldList)

    if (fieldCount == 1):
        return True
        return False

This is a function and it assumes you have already set the workspace environment.


        if (not FieldExist(myFeatureClass, "myField")):
          arcpy.AddError("Field 'myField' does not exist in " + myFeatureClass)

hope this is helpful.

Tips & Tricks: Extending your Entity Framework classes

There are different reasons why you would like to extend the existing properties on your entity framework classes, for instance when you want to add data validation attributes or the display attribute, commonly used in ASP.Net MVC to set the ‘display’ name of the property.

Here is how to do it without editing your auto generated Entity Framework (.edmx) file. ‘author’ is the entity framework class.

    public partial class author

    public class authorMetadata
        [Display(Name = "First name")]
        public string firstname { get; set; }

We further extend the original author class by adding another partial class and specify which class contains the metadata for the class using the Metadatatype attribute.

Windows Phone and the WriteableBitMapEx

I was investigating the use of the WriteableBitmap class and came across a great extension pack WriteableBitMapEx.

This also pointed me to a great demo written by Bill Reiss, explaining Blitting and Blending of images with the WriteableBitmap class. His original example was written in Silverlight and I was interested to see how easy it would be to port it to the Windows Phone and see how the performance would be.

Well it was really easy! I didn’t need to rewrite any code and hadn’t any problems with performance (in the emulator – Sadly enough i don’t have an actual Windows Phone yet)!

Here is the result:

Particle Windows Phone demo from Bjorn Kuiper on Vimeo.

Try it out yourself, here is the sourcecode of the Windows Phone solution:

Download the sourcecode.

Windows Phone development made easy! I love it that I don’t need to learn a new programming language to make my own phone apps!

Tips & Tricks: Accessing MembershipProvider from Silverlight

As you might noticed in the previous post, i’m working on a implementation of a custom MembershipProvider.

Well here is another useful link that shows how you can easily expose the AuthenticationService for your Silverlight application as a WCF Service:

Accessing the ASP.NET Authentication, Profile and Role Service in Silverlight

I will probably have some other posts coming up about using the MembershipProvider in Silverlight and ASP.Net, so keep an eye out.

Tips & Tricks: Debug custom MembershipProvider

Problems with debugging your custom MembershipProvider when trying to access it through the “ASP.Net Web Application Administration” website?

Here is how to do it:

In VS2010, goto “Debug”->”Attach to process” and select WebDev.WebServer40.exe from the list, click “Attach”. Now your debugger is attached to the ASP.NET WAA website. Be patient, the loading of the necessary debug symbols can take some time while accessing the webpage.

Also make sure that you do a clean rebuild if your membershipprovider is part of a different assembly so the ASP.NET WAA website is using the latest version of your build.