This year, I’ll be at the annual Microsoft DevDays in The Netherlands where you can ask me anything on web development. My base of operation at the conference will be somewhere in the ‘Ask-the-Experts’ area. Though you may also find me hanging around in the Community Lounge.

But if time permits, I seriously hope to find some time to go some sessions too. With many interesting sessions running in parallel and with limited time, it’s important to have some criteria up front to make a decision where to go, and what to skip. These criteria usually involve: speaker (good) and topic (interesting). That’s nice and easy, but how do know if a speaker is any good, and if the topic is interesting? Hopefully, some tips below may help in that respect.

First, I set a goal for my self. What is it that I want to take away from the conference? Do I have a current project or a future one in mind? Is a certain problem bugging me that needs to be resolved? That makes the topic more important than the speaker. On the other hand, I also like to be surprised. It can soon get boring and a waste of time to attend a session on a subject that you are very familiair with already. With a conference like TechEd I always learn most from the IT Pro sessions, because that’s an area that I usually only follow from afar. And you learn about stuff you hardly knew existed. Granted, it’s also stuff that’s not readily applicable in my own daily work.

Anyway, being interested in web development, and already trying to keep track of most stuff Microsoft pushes out. Here’s a list of sessions I’d like to attend on Day 1:

1. 09:15 - 10:45  The Keynote (link). Especially Rob Miles can put a smile on my face, but I’m not sure what his role will be as he’s only mentioned as a speaker and not his topic.

2. 13:30 - 14:45  Windows Azure AppFabric: Building, Managing, and Connecting High-Density, Multi-Tenant Cloud Applications (link). It’s quite a long title, but both the topic and speaker are interesting. The timeslot is difficult in that there are quite a few interesting sessions going on at the same time. Fallback-sessions, in case I can’t find the room (yes, that happens ) or it’s too crowded would be: Unlocking the Secrets of REST with WCF (link) and This Costs What? Estimating Costs in the Azure Cloud (link).

3. 15:05 - 16:20  Taking Control of your World with the .NET Micro Framework (link). Again with Rob Miles, just for the fun of it.

4. 16:30 - 17:45  This slot is again a challenge as several topics interest me, like What's New in Silverlight 5 (link), Test Driving ASP.NET MVC (link) but being really into C#, I should probably not miss Behind the Scenes of 10 C# Language Features by Bart De Smet (link).

In the evening, there’s GeekNight where the focus is on fun and less on function although the two can certainly mix well together. Mobile is hot it seems with cool sessions like:

Developing iPhone/iPad, Android and Windows Phone 7 Applications with C#, Visual Studio, Mono Touch en Mono Droid (link), Windows Phone in Rhyme and 3D (link) and Hoe Ontwikkel je een XNA Game voor de Phone 7, Xbox 360 en de PC met Dezelfde Code Base (link).

Actually, more sessions in the evening make me curious, but I haven’t managed to implement the me.Clone() method.

Then there’s Day 2, with these sessions on my agenda:

1. 09:15 - 10:30 HTML 5 - That's What You Need to Know Today (link) because I really need to get an update on the status of HTML5 and see if it’s usuable on websites with a large audience or not.

2. 10:50 - 12:05 Demystifying the .NET Asynchronous Programming Landscape (link) since async programming can be a lot simpler. At the same time, I’m running into disk I/O as the next bottleneck.

3. 13:15 - 14:30  Entity Framework 4 Tips en Tricks (link) although I’m a bit confused by the level-indicator: a 200-level ‘PowerTraining’ on subject that the audience should be familiar with. Alternatively, I could try Advanced Debugging with Visual Studio 2010 (link) with a great speaker on a difficult topic.

4. 14:50 - 16:05 WCF Web APIs, HTTP your way (link) even though I’m not a big fan of WCF (talking about configuration hell) but exposing APIs on a couple of projects I’m working on can be a great boost for exposure.

Not all timeslots are covered in this list. As I said, I should be at the Ask-the-Expert area as well. So it seems, you will only find me there on Day 1 from 10:45 to 13:30  and on Day 2 from 16:15 until the conference ends . In summary, there are more interesting sessions than time permits, so this year’s Microsoft DevDays should be a blast. Hope to see you there!

If you ever want to send updates to Twitter from C# it fairly easy to do. Recently, we added the option to send a tweet when someone registers for our upcoming dotNed user group meeting. Below is the client code.

using System;

using System.Web;

using System.Net;

using System.IO;

namespace Dotned.UI.Framework

{

    public class TwitterClient

    {

        public string Username { get; set; }

        public string Password { get; set; }

        public Exception Error { get; set; }

        private string _twitterUpdateUrl = "http://twitter.com/statuses/update.json";

        public TwitterClient(string userName, string password)

        {

            this.Username = userName;

            this.Password = password;

        }

        public void SendMessage(string message)

        {

            try

            {

                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(_twitterUpdateUrl);

                request.Credentials = new NetworkCredential(this.Username, this.Password);

                SetRequestParams(request);

                string post = string.Format("status={0}", HttpUtility.UrlEncode(message));

                using (Stream requestStream = request.GetRequestStream())

                {

                    using (StreamWriter writer = new StreamWriter(requestStream))

                    {

                        writer.Write(post);

                    }

                }

                WebResponse response = request.GetResponse();

                string content;

                using (Stream responseStream = response.GetResponseStream())

                {

                    using (StreamReader reader = new StreamReader(responseStream))

                    {

                        content = reader.ReadToEnd();

                    }

                }

            }

            catch (Exception ex)

            {

                Error = ex;

            }

        }

        private static void SetRequestParams(HttpWebRequest request)

        {

            System.Net.ServicePointManager.Expect100Continue = false;

            request.Timeout = 50000;

            request.Method = "POST";

            request.ContentType = "application/x-www-form-urlencoded"; 

        }

    }

}

It is important to notice that you need to set a static flag in the ServicePointManager. Otherwise, Twitter will reply with error 417 – Expectation Failed.  Here’s an example that shows how to use this class:

   1: TwitterClient client = new TwitterClient("__Sander", "[not telling you of course...]");

   2: client.SendMessage("Testing my twitter client code.");

Here’s a video I shot at the Silverlight panel discussion at TechEd Europe 2009 in Berlin.

Question was: what is the problem that Silverlight is trying to solve?

From what I could get out of the answers, the idea is threefold:

1. Silverlight is a solution to line of business applications that, for reasons of reach, need to run in the browser.
2. Silverlight is a media platform that support DRM and (live) streaming capabilities.
3. Silverlight is a better alternative to Flash, especially for developers that are comfortable with the .NET Framework and languages such as C# and Visual Basic.

These answers were not given all at once in this particular video, but it became more clear during the rest of the discussion.

Are the reasons mentioned here valid, and what’s your reason for using Silverlight?

As you know, IIS 7 is a powerful webserver. Just last month, after only three months of development time, we deployed the new website http://www.beurs.nl/ on an IIS 7 platform (with SQL Server 2008 back end).

This site, with over 7 mln pageviews/months, was built using ASP.NET MVC and Entitity Framework. A technology decision we haven't regretted. One advantage of ASP.NET MVC was the relative ease to support old urls that were still in use by other websites, and search engines. This meant that a url like http://www.beurs.nl/frame2.php still works. Sure, you can do that with simple URL rewriting, but obviously there are other advantages to using ASP.NET MVC. The webservers (three, load balanced) also run other sites, such as one for creating charts and another for the back-end CMS.

When figuring out which legacy urls to support, we found that the previous site had multiple aliases, such as koersen.beurs.nl, koersen3.beurs.nl, ticker.beurs.nl, etc. If we had a dedicated ip address for the primary site, and seperate ones for the other sites on the server, we could simply use a wildcard for all hostheaders. But... we do not. As a result, we needed to add each hostheader individually. The way to do this is described in this post. Though not difficult, it's quite a pain to do for 15 hostheaders, on three webservers. Yes, it's possible to share IIS 7 configuration, but we preferred not to. We do use DFS to mirror the website-folders.

As it turns out, it's not too difficult to add these binding from the command prompt:

c:\Windows\system32\inetsrv\appcmd.exe set site /site.name: www.beurs.nl /+bindings.[protocol='http',bindingInformation='*:80:forum.beurs.nl']
c:\Windows\system32\inetsrv\appcmd.exe set site /site.name: www.beurs.nl /+bindings.[protocol='http',bindingInformation='*:80:grafieken.beurs.nl']
c:\Windows\system32\inetsrv\appcmd.exe set site /site.name: www.beurs.nl /+bindings.[protocol='http',bindingInformation='*:80:koersen.beurs.nl']
...
etc

A simple script that takes 30 seconds to make and 2 seconds to run. AppCmd.exe is the single command line tool for managing IIS 7.0  that every developer/it pro should know.

These are the sessions for the OpenSpaceCode day.

Even though the Dutch Microsoft DevDays are still ahead of us, here’s a chance to look even further at TechEd Europe 2009. This year, it will be hosted in Berlin. But what is more surprising is the change back to a single week for both developers and IT pros. I certainly welcome this decision, and was never happy with the split that was made in the last few years. Even though I’m more active as a developer, I certainly spend a lot of time on managing a mixed Exchange 2003/2007 environment, and Windows Server 2003/2008 and need to help out every once in a while to troubleshoot on infrastructure.

But it would not only be for my personal benefit. I think it’s important and interesting for developers and IT pros to be able to see what’s happeing on the other side of the ‘fence’. Mark the dates in your calendar: 9-13 November 2009.

<asp:Button runat="server" id="Button1" visible="true" />

It is pretty straightforward to set the value of the visible-property in a code-behind page, like so:

protected void Page_Load(object sender, EventArgs e)
{
Button1.Visible = false;
}

However, it would be nice if you could to things like this

<asp:Button runat="server" id="Button1" visible='<% =User.IsInRole("Editor")%>' />

Cannot create an object of type 'System.Boolean' from its string representation
'<%= User.IsInRole("Editor") %>' for the 'Visible' property. 

<asp:Button runat="server" id="Button1" visible='<%# User.IsInRole("Editor") %>' />

As you can see, we simply add the pound/hash sign and remove the equals from the expression. This databind-expression is interpretered quite differently at runtime.

• <%= %> is in reality the same thing as Response.Write().

• <%# %> is more in related to assigning a value to an object. In the ASP.NET lifecycle, the <%# %> operators are evaluated before the page writes the first byte to the response buffer.

The problem with using a databinding expression is that you need to execute a DataBind() method either on the control itself or on the entire page. Executing DataBind() at page level can have negative side effects when you have multiple controls on the page with associated databinding logic. DataBind() at pagelevel triggers events, perhaps at times when you don’t want them. Using DataBind() in the codebehind for relevant controls defeats the idea a bit that we want to set a property with some simple rules and preferably in one place only.

A solution for this is to add another property (or attribute if you will), that just executes DataBind() on the current control. Something like this:

<asp:Button runat="server" id="Button1" visible='<%# User.IsInRole("Editor")%>'
code='<% DataBind(); %>' />

Unfortunately, that doesn’t work, because at runtime, the ASP.NET rendering engine will complain that a Button-control doesn’t have a property “code” so it doesn’t know what to do with it. However, we can trick it to ignore the property for rendering, but still execute the code, like so:

<asp:Button runat="server" id="Button1" visible='<%# User.IsInRole("Editor")%>' 
meta:code='<% DataBind(); %>' />

Prefixing the attribute with the text meta: with make the renderer ignore the value, but the code will still execute. Please note that the example uses meta:code, but it doesn’t really matter what name you give the attribute. It could be meta:execute or meta:whateveryouwant, as long as it’s not meta:resourceKey, because that property has special meaning.

It may not be the most elegant solution, but hey, if it works, I’m ok with it. With the rise of ASP.NET MVC we’ll probably see more of this type of coding anyway.

Yes, that’s right. If you are working with Sharepoint, you can download the designer for free. Here’s where you can donwload it: http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=baa3ad86-bfc1-4bd4-9812-d9e710d44f42

For some reason, the e-mail took a detour, but I got it (thanks Gerard):

“Congratulations! We are pleased to present you with the 2009 Microsoft® MVP Award! This award is given to exceptional technical community leaders who actively share their high quality, real world expertise with others.”

Beside the recognition for past efforts, it also  feels as a stimulus to continue. Although.. I enjoy writing and helping out anyway. Nonetheless, recent projects like www.vaderradar.se, www.sat24.com, www.niederschlagsradar.de, and especially www.360.org have taken a bite out of my available time.

I’ll be hanging around the community area at the upcoming DevDays. This year, the event is around the corner from my house. Excellent! Hope to see you there.

I will certainly not be the first, nor the last, but here it is. ASP.NET MVC 1.0 final version is released.

Download ASP.NET MVC 1.0 here.