Erwin's Blog

Creating a delimiter separated list from list of strings

2009-06-24T09:15:00Z

When you have a list of strings like IList<string> of IEnumerable<string> and you want to convert it to for example a comma separated list you can easily do that with the String.Join method.

List<string> list = new List<string>() { "A" , "B", "C", "D", "E" };

string commaSeparated = String.Join(",", list.ToArray());

The output will be like this:

A,B,C,D,E

This is an easy and clean way to create a delimiter separeated list of strings.

DevDays ‘09 The Netherlands day #2

2009-05-29T18:41:00Z

The second day of DevDays and 5 more interesting sessions to follow.

At 9:15 the first session of this day started it called “Functional Programming in C#” from Oliver Sturm. In this session we dived deep in to C# with a lot of C# 3.5 LINQ and lambda expressions. The question was, why would we use functional programming in C#, the answer was given with some practical examples.

The second session of today was about “Building RESTful services with the ADO.NET Data Services “given by Jurgen Postelmans. ADO.NET Data Services is build on top of the Web Programming Model of WCF. In this session we find out how easily it is to create and consume REST data services on the web. In a few minutes you can create a service that exposed your data to the web.

A funny and cool session was the third session of today, “Make Yourself Rich with XNA” from Rob Miles. He shows us in a funny way how you easily create a game in XNA. He uses the PC and a xbox controller to control the game, he also deployed the game on a Zune player. In the session we build a pong game from scratch that can be controlled with the wireless xbox controller, it was surprisingly easy to create. Oh and I think I should mention his book ;-).

The fourth session of today “IE8 and Web Standards” given by Peter-Paul Koch. What is the purpose of using web standards of today? He gives some examples how to implement the W3C web standards and give some tips and tricks. He also talked about the new IE8 browser from Microsoft and how it implements the web standards.

Last and fifth session of today in the great hall (with great chairs, i needed that after this long day) about “ASP.NET MVC Introduction” from Fritz Onion. This talk was about the ASP.NET MVC framework, he talked about the differences between typical ASP.NET applications and the ASP.NET MVC application. How do we use models, views and controllers to create a functional web application and what advantages does this model offer over the standard web forms model?

After this long day DevDays ‘09 came to an end, it was very interesting to attend all these sessions.

DevDays ‘09 The Netherlands day #1

2009-05-28T19:19:57Z

Today was the first day of DevDays ‘09 in the World Forum in The Hague city. There are around 80 sessions in these two days, from cloud computing, .NET, Ajax to Silverlight and a lot more subjects.

The first sessions of today was the key note session with David Chappel, the talk was about Microsoft's cloud computing platform Azure. He told us what this new technology means and what it can do, like how do we use it in practice. The technologies that came by are Windows Azure, .NET Services and SQL services. He also mentioned some alternatives like Amazone EC2, Google Appengine and Salesforce Platform.

The second talk I went to was C# 4.0 and the Future of C# from Krishnan Subramanian, in a very packed hall he talked about dynamic & functional languages and concurrent programming. Some topics where dynamically typed objects, optional and named parameters, improved to COM interoperability and co and contra-variance. He also talked about the future of C# and gives use some cool demo’s about on the fly compiling and running of C# code.

The third talk was about attack and defense and securing ASP.NET applications from Keith Brown, after some very nice yo-yo tricks Keith talked about how-to secure our Web applications from potential hackers. The topics that came along are server side validation, user rights, filtering, SQL injection and XSS. He also showed us how easy it was to hack a product database search web application with SQL injection if you doesn’t use parameterized queries.

In forth and last talk Fritz Onion talked about ASP.NET AJAX 4.0. How do we improve our client-side development experience this was the main subject of the talk. The talk covers subjects like the new client-side template and data binding model, declarative control instantiation, the new DataView control, markup extensions, and bindings. With ASP.NET AJAX 4.0 we can faster build quickly responding web application without creating a lot of client side code your self.

The event is very well organized at a nice location, tomorrow day two with a lot of new interesting sessions.

Convert string to byte array and byte array to string

2009-05-01T11:19:00Z

How do we convert a string to a byte array (byte[]) and the other way around. The most simple way to do this is with the Encoding class:

String to bytes:

byte[] bytes = Encoding.UTF8.GetBytes("foo");

Bytes to string:

string foo = Encoding.ASCII.GetString(bytes);

But what if you don’t know the encoding type? Well you can use the following code snippet to change the string to byte array and byte array to string:

String to bytes:

   1:  public static byte[] ConvertStringToBytes(string input)

   2:  {

   3:    MemoryStream stream = new MemoryStream();

4:

   5:    using (StreamWriter writer = new StreamWriter(stream))

   6:    {

   7:      writer.Write(input);

   8:      writer.Flush();

   9:    }

10:

  11:    return stream.ToArray();

  12:  }

Bytes to string:

   1:  public static string ConvertBytesToString(byte[] bytes)

   2:  {

   3:    string output = String.Empty;

4:

   5:    MemoryStream stream = new MemoryStream(bytes);

   6:    stream.Position = 0;

7:

   8:    using (StreamReader reader = new StreamReader(stream))

   9:    {

  10:      output = reader.ReadToEnd();

  11:    }

12:

  13:    return output;

  14:  }

With this snippets you can convert if you don’t know the encoding of a certain string.

Umbraco Demo

2009-04-17T07:36:00Z

Last week I have seen a Demo about Umbraco, the demo was given by Richard Soeteman from Soetemansoftware an experienced Umbraco developer.

Umbraco is a CMS that fully integrated with .NET, it’s supports .NET out of the out-of-the-box, you can use .NET Custom Controls and .NET User Controls without extra effort. You can place your controls everywhere in the template and even in the rich text editor, Umbraco can also send data to your controls via Public Properties. Umbraco is fully compatible with ASP.NET Ajax and javascript frameworks like jQuery and prototype.

The templates in Umbraco are build with XSLT, with XSLT so you are very flexible to create your html. Umbraco supports also XSLT extension methods, so when you miss some functionality in XSLT you can create methods it in .NET and call them from your XSLT templates.

What’s also great about Umbraco is the event model, you can hook up at a lot of events and create your own logic. Hooking into these events is simply a matter of creating a .NET class that implements an interface.

What i haven’t mentioned yet is that Umbraco is licensed under the MIT license, so you can see and modify all the source code, but isn’t likely that you will change the source because it support mostly all features that are needed.

Richard Soeteman have given us Demo that includes most of aspects of Umbraco. First we did the installation of Umbraco. It’s very easy to install Umbraco, you only have to unzip Umbraco to the wwwroot and request the website and follow the configuration wizard. You can start with a empty Umbraco or with a starter kit.

In the demo we started with the starter kit Umbraco installation and we added also some packages that are needed for the demo, we modified some templates and created some usercontrols in Visual Studio and added them to Umbraco.

With this demo I get a good impression about Umbraco, Umbraco is very easy to use and to implement. So if your are searching for a open source .NET CMS, try it out at umbraco.org

Add Web Reference with certificates on https

2009-01-27T18:53:39Z

Today I was adding a webservice via "Add Web Reference" to my project. The webservice was only accessible on https with a client certificate. When I did "Add Web Reference" I got a "The underlying connection was closed: Could not establish secure channel for SSL/TLS", but in IE it's works perfect. After some research I found an other way to add the webservice via "Add Web Reference". You can do it like this:

Save the WSDL to a location on your machine.
Copy the path.
Go to the Add Web Reference in your project.
Paste the path you copied into the URL.
Click on Go.
Click on Add Reference

Don't forget to change the webservice url in your Web.config or App.config.

One web setup project for deploying on multiple environments

2009-01-21T20:48:00Z

A common task in a project is preparing your for a deployment. The easiest way to do this is making use of a Web Setup Project. But how do we make this Web Setup Project suitable for multiple environments, because it's most likely that there are environments like Development, Test, Acceptance and Production.

The key to this solution is the "Condition" property. If you add a file to the Web Setup Project (In the File System view right mouse button on the Web Application Folder, then Add -> File) and select it you can find the "Condition" property in the properties window.

We add the following value to the "Condition" property ENV="Prod", this is for the production environment, for the test environment it will be something like this ENV="Test".

We also set the "TargetName" propery to Web.Config so the Web Setup Project will output the configuration file as Web.Config.

Well you can add unlimited Web.Config files to your Web Setup Project, they are all output as Web.Config but not all at the same time. So how can we choose the correct Web.Config for your environment, well like this:

%windir%\system32\msiexec.exe /i "Setup.msi" ENV="Prod"

msiexec.exe (the Windows installer)
/i (is the install switch)
"Setup.msi" (compiled output of the Web Setup Project)
ENV="Prod" (the condition value).

If you run this the setup will be started, after the setup is finished you will notice that only the Web.Config is installed with the "Condition" property set to ENV="Prod".

To make this all fool proof you can make a shortcut to this command line, like this:

Now when you click on this shortcut you get the same result.

So with this solution you can make one Web Setup Project for all your environments and create a better and stable deployment solution.

New jQuery release version 1.3

2009-01-15T13:23:52Z

Yesterday jQuery released their new version, number 1.3. They did a lot af changes / bugfixing, performance improvements.

The big features are:

Sizzle: A sizzlin’ hot CSS selector engine.
Live Events: Event delegation with a jQuery twist.
jQuery Event Overhaul: Completely rewired to simplify event handling.
HTML Injection Rewrite: Lightning-fast HTML appending.
Offset Rewrite: Super-quick position calculation.
No More Browser Sniffing: Using feature detection to help jQuery last for many more years to come.

They did a pretty good job on the performance:

Selector performance, 49% faster:

Delegation filtering performance, 30x times faster:

Element insertion performance, 6x faster:

Offset rewrite, 3x times faster:

There is also a new API browser released with the following features:

All the latest jQuery and jQuery UI documentation.
The ability to mark pages as favorites for those pages you keep wanting to return to.
Syntax highlighting in the code examples
Live running of examples within the browser
Links to edit and experiment with the code examples

You can find it here:

http://api.jquery.com/

The new version you can download here:

Downloading jQuery

Or you can use the google hosted version:

Google AJAX Libraries API

More info:
Blog: jQuery 1.3 and the jQuery foundation
Release notes

Ajax.NET debugging

2009-01-13T11:04:00Z

Most people use alert() to debug their JavaScript, but the Microsoft Ajax Library has a better alterative Sys.Debug. Sys.Debug has some methods for logging messages to the browser console. Like this:

To log a message:

Sys.Debug.trace(“Log to the console”)

To log an object:

Sys.Debug.traceDump(someObject);

You can use Web Development Helper for IE, and Firebug for Firefox to see your console messages. Or use textarea element with the id "TraceConsole" to trace your messages:

<textarea id=”TraceConsole” rows=”50” cols=”50”></textarea>

From:

http://weblogs.asp.net/alnurismail/archive/2009/01/12/a-better-alternative-to-using-alert-for-debugging.aspx

25 excellent tips to improve your jQuery

2008-12-24T08:59:00Z

More and more ASP.NET developers are going to use jQuery. jQuery is a fast and easy to use javascript framework.

On the tvi design blog a nice article has been posted with some very excellent tips how to improve your jQuery. All tips are very useful and gives you easy improvements, so take a look!

Edit existing assemblies when you have no source code

2008-12-15T23:33:00Z

Every now and then there are situations when you have no source code available, because you lost it or you don't get it. There are some solutions to see or get the source code, with Reflector you can see the source code but you can't edit it, but with reflector you can do a lot more.

You can add add-ins to Reflector, like FileDissembler this plugin dump all source code of the assembly to a folder and create a solution file so you can open it Visual Studio.

Sometimes the recompile won't work or it's a lot of extra work, then you can use the Reflector plugin Reflexil with this assembly you able to edit the IL (Intermediate Language) code of the assembly and save it back to a dll file. This is very handy to solve little issues, like changing plain text that's compiled within the assembly and yes then you know why it isn't handy to put plain text in your source code.

How to detect search engine crawlers?

2008-11-28T15:05:00Z

Today I was looking for a solution how to detect when a client is a search engine crawler, you can create a fancy solution for this, but in the .NET framework their is already a solution to detect search engine crawler. The property Request.Browser.Crawler. If you use this property you always get false even if the site is visited by a search engine crawler, that's because it's not configured in a default installation of .NET.

ASP.NET uses the <browsercaps> section in machine.config or web.config to determine the client browser is a crawler or not. In the default installation the crawler filter information is all blank, that's why you'd always get false. To fix this problem, you should add the search engine crawler filters in the <browsercaps> and add this section to your web.config. Like this:

<configuration>
 
<!-- ...... -->
 
  <system.web>
 
    <browserCaps>
 
      <filter>
 
       <!-- Google Crawler -->
        <case match="Googlebot">
          browser=Googlebot
          crawler=true
        </case>
 
        <!-- Yahoo Crawler -->
        <case match="http\:\/\/help.yahoo.com\/help\/us\/ysearch\/slurp">
          browser=YahooCrawler
          crawler=true
        </case>
       
        <!-- MSN Crawler -->
        <case match="msnbot">
          browser=msnbot
          crawler=true
        </case>
       
        <!-- check Alta Vista (Mercator) -->
        <case match="Mercator">
          browser=AltaVista
          crawler=true
        </case>
 
        <!-- check Slurp (Yahoo uses this as well) -->
        <case match="Slurp">
          browser=Slurp
          crawler=true
        </case>
       
        <!-- Baidu Crawler -->
        <case match="Baiduspider">
          browser=Baiduspider
          crawler=true
        </case>
 
        <!-- check Excite -->
        <case match="ArchitextSpider">
          browser=Excite
          crawler=true
        </case>
 
        <!-- Lycos -->
        <case match="Lycos_Spider">
          browser=Lycos
          crawler=true
        </case>
 
        <!-- Ask Jeeves -->
        <case match="Ask Jeeves">
          browser=AskJeaves
          crawler=true
        </case>
 
        <!-- IBM Research Web Crawler -->
        <case match="http\:\/\/www\.almaden.ibm.com\/cs\/crawler">
          browser=IBMResearchWebCrawler
          crawler=true
        </case>
 
      </filter>
 
    </browserCaps>
 
  </system.web>
 
 </configuration>

Tip: you can find more crawler info in your IIS logs ([Windows Folder]\system32\LogFiles)

From

New ASP.NET Charting Control

2008-11-27T09:12:00Z

Microsoft has released a new cool charting control. It comes with documentations, samples and a lot of features, features like:

All supported chart types.
Data series, chart areas, axes, legends, labels, titles, and more.
Data Binding
Data manipulation, such as copying, splitting, merging, alignment, grouping, sorting, searching, filtering, and more.
Statistical formulas and financial formulas.
Advanced chart appearance, such as 3D, anti-aliasing, lighting, perspective, and more.
Chart rendering.
Events and Customizations.
Interactivity and AJAX.

Below some pictures of sample charts:

More information:

Parse QueryString with the HttpUtility

2008-11-21T12:45:00Z

If you have a querystring from for example the Uri class (Uri.Query) and you want to parse it so you can get al the params and values, instead of doing al lot of string manipulation you can use a very handy utility class, the HttpUtility. The HttpUtility class has a method ParseQueryString, this method parse a query string into a namevaluecollection. Like this:

string querystring = "?var1=test&var2=test2"
 
NameValueCollection nvColl = HttpUtility.ParseQueryString(querystring);
 
string var1 = nvColl["var1"];
string var2 = nvColl["var2"];

The string "var1" contains "test" and the "var2" contains "test2".

VS2008 SP1 Hotfix to Support for intellisense Doc Files

2008-11-10T08:35:00Z

A few week I mentioned how to get intellisense for jQuery. Now the visual studio web tools team released a hotfix so the intellisense files will be found automatically if they have the same name as the orginal js file and the suffix "-vsdoc.js" more info can be found on the Visual Studio Web Tools team blog