knom's developer corner : Development

LINQ-To-Everywhere – List of LINQ Providers

knom — Mon, 27 Apr 2009 12:23:05 GMT

This weekend I’ve built a small application, which queries the “Simpsons” seasons guide data and updates the filenames/descriptions. To do this I needed to query a CSV file. While searching for a LINQ to CSV file implementation I’ve found an interesting list of LINQ Providers provider by MVP Charlie Calvert.

LINQ to CSV

LINQ to Amazon

LINQ to Active Directory

LINQ to Bindable Sources (SyncLINQ)

LINQ to C# project

LINQ to Continuous Data (CLinq)

LINQ to CRM

LINQ To Geo - Language Integrated Query for Geospatial Data

LINQ to Excel

LINQ to Expressions (MetaLinq)

LINQ Extender (Toolkit for building LINQ Providers)

LINQ to Flickr

LINQ to Google

LINQ to Indexes (LINQ and i40)

LINQ to IQueryable (Matt Warren on Providers)

LINQ to Metaweb(freebase)

LINQ to MySQL, Oracle and PostgreSql (DbLinq)

LINQ to NCover

LINQ to Opf3

LINQ to Parallel (PLINQ)

Slides and Demos from BigDays 2009 are online!

knom — Mon, 23 Mar 2009 00:22:00 GMT

These days I'm travelling around austria with our biggest developer & IT Pro event Big>Days 2009!

This year's theme was "packen wir's an" - translated "let's get to work"!

Accompanying the theme we built a multi-tier application with .NET 3.5 and Silverlight called "Rent-A-Worker"!

You can download the sources at http://www.codeplex.com/BigDays09/!

If you're interested in the slides of my four sessoins, feel free to get them here

Upgrade TFS 2008 Workgroup Edition to Standard Edition

knom — Mon, 09 Feb 2009 19:46:33 GMT

I’ve had a little playground TFS 2008 installation for a while for use with some “pet-projects”. I used TFS 2008 Workgroup Edition for this, as this is already part of MSDN subscription package. This edition works the same as the full one, but is limited to 5 users.

Now that I needed more user accounts for a larger project I tried to upgrade to TFS 2008 Standard Edition.

This seems to be pretty easy:

1.) Open Add/Remove Programs in control panel.
2.) Select “Visual Studio 2008 Team System – Team Foundation Server” and choose “Change”.

3.) At the TFS setup, select “Upgrade” and enter the new serial number.

4.) Finished.

(Summarized from Brian Harry's Weblog)

This is great, but unfortunately the serial number boxes are disabled / grayed out on my system (and all others as well) :-)

So it’s harder than expected…

But.. thanks to a thread in the MSDN Forums I found a way to change the serial number.

All you need to do (as step 0.) is open setup.sdb in
"Program Files\Microsoft Visual Studio 2008 Team Foundation Server\Microsoft Visual Studio 2008 Team Foundation Server - ENU"
and change the [Product Key] value (skip the dashes).

Voila!

WPF Webcast - New Year's resolutions

knom — Wed, 07 Jan 2009 13:34:39 GMT

I’ve a lot of New Year’s resolutions for 2009 :-) One of them is to blog more often (we’ll see how this works..) another is to do a series of webcasts around WPF.
We’re starting with our first WPF webcast on Friday, January 9th at 10am with an overview over WPF and XAML.

Topics we’ll cover:
*) Why a new UI framework
*) What tools, frameworks, .. do we need for WPF?
*) What is XAML, what is it’s syntax.

>> Register now at the Webcast Website

WPF Day in Dublin

knom — Wed, 17 Dec 2008 17:56:00 GMT

Last week I was in Dublin doing two sessions on WPF for Microsoft Ireland.

They did a "Client-UI Day", where they featured WPF and Silverlight.

The first session was given by the Irish Developer Evangelist Ronan Geraghty, who did an introduction to the Microsoft Client Platform, showing the differences between AJAX, Silverlight, WPF and when to use what.

Next I did a WPF for beginners session, where I showed all the details of XAML, Databinding, Styles, Templates, etc...

Afterwards my colleague Martha Rother from Ireland did a session on Silverlight.

Last but not least I showed how to leverage WPF and Composite WPF Guidance ("Prism") to build business applications.

Overall a really nice event, with around 80 attendees and a lot of interesting ideas and feedback on the Microsoft Client Continuum.

If you're interested in my slides on WPF Introduction and Composite WPF, find them here:

WPF Sessions.zip

Going home from Ireland I took two flights via London.. What a bad choice.. I drove to Dublin Airport at 6:30 am, arriving in Vienna at 5pm :-) Almost half a day of traveling and waiting...

A Valuable Tool for WPF and Silverlight

knom — Wed, 03 Dec 2008 12:14:50 GMT

Working with WPF & Silverlight is really great!

The only problem if you use it in production is how you quickly generate new views. They don't need any animations or other stuff, just plain details views.

You could do it with Expression Blend or the Visual Studio WPF Designer, still it would take more time than doing it directly in XAML..

But.. Who is interested in writing 30 or so views in XAML ?!

There is a better solution: XAML Powertoys.

XAML Powertoys are a bunch of Visual Studio 2008 additions which really ease your daily work with XAML (either in WPF or in Silverlight).

Let's say you have an entity Person and you want to create a list view for it.

Just select "Create Form, ListView,.." in the "XAML Power Toys" context menu within the XAML designer.

Next you select the type..

Next you can select the type of UI you want to create (either form, WPF ListView or the new DataGrid control).

You can select the participating data fields from the class and configure how they are bound, etc...

That's it.. The XAML is automatically created and copied into your clipboard. Just paste it at the corresponding position and your UI is ready!

> Get the XAML PowerToys here.

But don't forget to add the install-path to trusted Add-In paths under Tools-Options:

Using the VS Templates for Composite-WPF-Guidance

knom — Wed, 22 Oct 2008 18:28:28 GMT

This is about using the templates for a new project.

First of all you need to download the templates and install them from the links below.

Download the ZIP-File containing sources and built binaries here.

See the post on how to install the binaries or build the sources here.

Let's start setting up our new project:

Create a new root folder for your solution (e.g. C:\temp\DemoClient\).
Within the root folder create a Libraries (or other named) folder for the P&P assemblies, like Unity and Composite App Library.
Copy the necessary assemblies to the Libraries folder (build the Composite Application Guidance projects to get them):
Now open Visual Studio choose "File - New Project" and select "Composite WPF Solution" from "Visual C# > Composite App Guidance".
Enter the name of your overall solution (like "CompositeClient") and specify the root folder created before.

Important: "Create directory for solution" should be unchecked, to automatically insert references later. Press "OK" then.
A new wizard pops up:

You can now change your root namespace or the namespaces for the shell and infrastructure project.
It's important to specify the relative path to the Library folder (starting from the specified root folder). In this case it's Libraries. After that, the new solution is going to be created.
Select "Add New Project" on the Modules folder.
Choose "Composite WPF Module" and enter the Modules path of the solution as the location
(e.g. C:\temp\DemoClient\CompositeClient\Modules\).
Enter a name for the module (e.g. CompositeClient.Modules.Foo).
The New Module Wizard pops up.

Press Finish (or change the IModule class name or module namespace).
A new project is created, containing an IModule implementation and a module controller class.
When choosing Add-New Item, you can add a new Composite WPF View and Presentation Model to the module.

Enter a name for the new items (not containing "View" or any other types). Just use "DoFoo" for instance.
The New View Wizard pops up, letting you choose the names for view, presentation model and interfaces.
Choose Finish.
A new subfolder is created, containing the files necessary for the view.

Note 1: When using the item template for the first time, you might get a dialog requesting to trust the template. Press trust there!

Note 2: The wizards say "Composite WPF Guidance Contrib", as I hope to get into the Contrib project with this ;-)

Team System + Gadgets + Outlook

knom — Wed, 15 Oct 2008 16:44:12 GMT

If you're using Team Foundation Server, these utilities might be useful for your everyday's work:

*) WorkItem Outlook Plugin

Create a workitem directly out of the mail view.

Download

*) Team System Build Monitor Gadget

Always be aware of the status of your TFS builds in the sidebar.

Download

*) Two useful WorkItem Gadgets

Get the state of your open workitems, or the work items per project.

Download

A Must Have Tool - VS 2008 Snippet Designer

knom — Thu, 09 Oct 2008 14:23:25 GMT

Mathew Manela from the Online Tools Group at Microsoft has written a really cool tool, which adds a feature missing for a long time in Visual Studio: Code Snippet Creation.

The tool, which is available at http://www.codeplex.com/SnippetDesigner allows a bunch of functionality for working with custom snippets.

Add a new .SNIPPET file via File-New-File--Code Snippet File
Export existing code into a snippet:
Simply right click on the selected code and press "Export as Snippet".
Edit snippets (set placeholders, etc..)
The editor is opened after exporting something.
Additionally you can later on open .snippet files out of the "Snippet Explorer" (see below).
The Snippet Explorer
Go to "View - Other Windows - Snippet Explorer" to search for existing snippets.

The snippets you build are stored under the path %USERPROFILE%\Documents\Visual Studio 2008\Code Snippets\Visual C#\My Code Snippets.

You can either insert them via the context menu "Insert Code Snippet"
(Ctrl+K-X) or you can assign a short-phrase (shortcut).

With the shortcut you just need to type e.g. prop<tab><tab> to insert a property code snippet.

You can set the shortcut (and other things as well) in the property window of the snippet editor.

.NET Roadshow - Demo Solution

knom — Fri, 19 Sep 2008 17:07:00 GMT

The demo solution from our .NET Beginners Roadshow is no ready for download for attendees and all others.

The scenario is event management.

The solution consists of 4 parts:

*) Data Access layer using ADO.NET Entity Framework

*) Business Logic Service hosted as a WCF service.

*) Web Site, written in ASP.NET, which allows attendees to register and view their events, including a

*) Silverlight Web Control

*) Desktop Client using WPF, for managing the events.

Here some screen shots:

Feel free to have a look at the source code here.

Whitepaper - "InfoScreen App with Silverlight 1.0"

knom — Fri, 06 Jun 2008 14:30:00 GMT

One of our mail goals in the Developer & Platform Evangelism is driving adoption of new technologies. To do so we're working with strategic customers which are interested in our stuff and help them implementing projects.

A few months ago we started working with derStandard.at, which is a well-known website in Austria, that is attached to one of the largest country-wide newspapers.

They're looking for new innovative ways to provide their content. That's why they evaluated Silverlight for a new InfoScreen application of theirs.

My colleague Mario Szpuszta and I supported derStandard.at in architectural design and prototyping of their project.

As a conclusion we've written a whitepaper on the architecture of the application and some best practices when working with Silverlight 1.0.

By the time we started the project, Silverlight 1.0 was the stable release of the new platform, that's why we've decided to use the first, JavaScript based version. derStandard.at will update their project to Silverlight 2.0 and so will we update the whitepaper (if you're interested in us doing so).

Feel free to download the whitepaper here and see our experiences with building an InfoScreen application with Silverlight 1.0.

BigDays 2008 - Slides and Demos

knom — Wed, 16 Apr 2008 19:32:55 GMT

Here are the slides and demos of my four sessions at the Austrian Launch Tour "Big>Days 2008".

Sorry for the delay.. I've been in a hurry during the last days.. So following the high demand, here they are :-)

Visual Studio 2008

Language Integrated Queries with C# 3.0

Slides
Demos

Silverlight 2.0

Slides
Demos

Windows Presentation Foundation for Line-Of-Business Applications

Slides
Demos

"Hacking" System.Net.Mail.SmtpClient

knom — Wed, 16 Apr 2008 17:48:08 GMT

In .NET 2.0 there is a cool class called SmtpClient within System.Net.Mail.

With this class you can send mail (at least I thought).
The requirement was to send an email over a server of one of our agencies.
The mail server was secured by username/password authentication. That's why I used the following code:

SmtpClient _client = new SmtpClient();
_client = new SmtpClient("smtp.myserver.at");

_client.UseDefaultCredentials = false;
_client.Credentials = new NetworkCredential("username", "password");

_client.Send("from@test.at", "to@test.at", "Hallo Welt", "Hallo max!!");

At execution of the last statement an exceptíon occurred:

The inner exception said "Invalid lenght for a Base-64 char array."

That didn't make any sense for me (nor helped me to fix the problem).

I had a look at the stack trace and found out, that the exception had occurred in a class called
SmtpNtlmAuthenticationModule.

So I used telnet to manually connect to the smtp server.

S: 220 smtp.myserver.at ESMTP
C: ehlo asd.com
S: 250-smtp.myserver.at Hello mypc.microsoft.com [xxx.xxx.xxx.xxx]
S: 250-SIZE 20971520
S: 250-PIPELINING
S: 250-AUTH PLAIN LOGIN CRAM-MD5 NTLM
C: AUTH NTLM <base64 encoded string>
S: 334 NTLM supported

Seemed like the server would support NTLM.. But.. when I looked up the NTLM-SMTP specification,I found out that the server should respond with

334 <NTLM supported as base64 encoded string>

So the problem obviously is, that "NTLM supported" was not a valid Base-64 encoded string (as the inner exception above also pointed out).

So how could this problem be solved...

I digged into the private members of the SmtpClient object and found a member called transport (of type SmtpTransport).

The SmtpTransport object had private members as well, and one of them was called authenticationModules - bingo!

This is an array of ISmtpAuthenticationModules like Negotiate, NTLM, Digest and Login.

Unfortunately SmtpClient always picks the most effective supported method (in this case NTLM). As NTLM was not working I needed a way to kick out NTLM of the list of supported auth methods.

So I used reflection to modify the array and "disable" (override) NTLM in the array. Here's what I did:

FieldInfo transport = _client.GetType().GetField("transport",
    BindingFlags.NonPublic | BindingFlags.Instance);

FieldInfo authModules = transport.GetValue(_client).GetType()
    .GetField("authenticationModules",
        BindingFlags.NonPublic | BindingFlags.Instance);

Array modulesArray = authModules.GetValue(transport.GetValue(_client)) as Array;
modulesArray.SetValue(modulesArray.GetValue(2), 0);
modulesArray.SetValue(modulesArray.GetValue(2), 1);
modulesArray.SetValue(modulesArray.GetValue(2), 3);

Voila!

Guess which smtp authentication module will be used now :-)

WcfSvcHost and WcfTestClient in VS 2008

knom — Mon, 24 Mar 2008 22:09:57 GMT

There are two nice helper apps included in Visual Studio 2008, which allow you to test-host your WCF service and invoke the methods to check they're working correctly.

The two apps are called WcfSvcHost.exe and WcfTestClient.exe.

By default they are set as default debugging activity in all WCF libraries. See how to get use of them:

Create a new WCF Service Library
Build an interface "ISayMyNameService" with a class parameter named "Name"
Implement a new service class
Change the class name of the hosted service in app.config:
Press F5 and start debugging.
Voila - the WcfSvcHost is started an displays a successfull message. Click on the message for details:
At the same time the WcfTestClient got started and is now displaying a n UI for testing our simple WCF service. Double click on "HelloYou()" to invoke the method with parameters:
Press "Invoke" and wait for the service to complete. You'll then get back the response as a formatted list or in raw XML.
If you don't want the WcfTestClient, but your custom test client you can change the setting under the project properties:

Inside Workflow Foundation Activities

knom — Sat, 01 Mar 2008 22:17:28 GMT

Activities are the heart of WF. Together they form workflows, control the flow or do loops.

They can either be simple and atomic or composite.

Simple activities can do one thing as calling a database or web service, terminating the workflow or something else.

Composite activities consist of other activities - they have children within. If the "parent" composite activity is executed, it controls which children are executed in which order. The simplest composite activity, the sequence executes all it's children in a sequential way. A parallel activity consists of several sequences executes at the same time. But there are even more complex composite activities like IF statements, or loops. Even the entire workflow (either sequential or state machine based) is nothing more than a special activity with custom logic and additional properties.

Regardless of whether it is a simple or composite activity, each activity (at least somewhere above in the inheritance tree) inherits of Activity class.

public class MyActivity : Activity
{
    protected override void Initialize(IServiceProvider provider);

    protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext);
    protected override ActivityExecutionStatus Cancel(ActivityExecutionContext executionContext);
    protected override ActivityExecutionStatus HandleFault(ActivityExecutionContext executionContext,
                                                                Exception exception);
    protected override void Uninitialize(IServiceProvider provider);
}

What you get, is basic virtual methods, which you can override to provide the behaviour of your activity for this state.

Speaking of states - each activity implements a finite state machine. That means the activity is guaranteed to be in one of the following states: State transitions may occur only in the directions of the arrows. White arrows are runtime-, yellow ones developer initiated.

This activity automaton displays the entire lifecycle of an activity:

At creation of the workflow Initialize() is called on all activities. They are afterwards placed in the Initialized state.
The activity is placed into Executing state and it's Executing() method is called. Within it the activity's actual work is done.
If an error occurs, the activity automatically transitions into Faulting, and HandleFault() is called.
Executing activities can be canceled by other activities to stop their execution.
Finally if all the execution, cancellation or fault handling work is done, the activity is closed by the developer.
Additionally there is the possibility to "undo" already executed activities. For that situation you can implement the ICompensatableActivity interface, which defines a Compensate() method. This method is called in the Compensating state and allows you to provide custom undo logic.

So to write you custom little activity, just inherit of the Activity base class and override the suitable methods for the states you want to provider logic for. To pass data from outside into the activity you can use DependencyProperties, a new concept in .NET 3.0 which are also used with WPF.

Here is a sample of a ConsoleWritelineActivity:

public class ConsoleWriteline : Activity
{
    public static DependencyProperty OutputProperty = DependencyProperty.Register("Output",
        typeof(string), typeof(ConsoleWriteline));

    public string Output
    {
        get
        {
            return ((string)(base.GetValue(ConsoleWriteline.OutputProperty)));
        }
        set
        {
            base.SetValue(ConsoleWriteline.OutputProperty, value);
        }
    }
    protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
    {
        Console.WriteLine(this.Output);
        return ActivityExecutionStatus.Closed;
    }
}