Use ApplicationException when creating your own custom exceptions

In March of 2009 I talked about Catch (Exception e): Right or wrong?. Since that time I've gotten into the habit of also deriving my custom application exceptions from the .NET ApplicationException rather than just Exception. This .NET class serves to help identify exceptions that are specific to an application, hence the name.

To make things really easy for us to create application-specific exceptions, use the Visual Studio 2010 code snippet, "exception". Be sure to use the tab key to update the base class to ApplicationException. The snippet contains all the code to adhere to the exception derivation best practices.

Very handy!

.NET 4 / C# Code Contracts

It has been hard to find good content on the new .NET 4 code contract stuff for C#. Here is a Microsoft "User Manual" I found dated Sep. 2010. It is pretty good.

Download the PDF here.

Fast and easy way to search files using C# TPL

I wanted to play around with the .NET 4 Task Parallel Library (TPL) a bit so I wrote a "Task" oriented app to perform a file name and/or content search. The UI is Windows Forms. It's nothing pretty, but I found it to be much faster than using Windows Explorer when recursing down big trees and across network shares. The code is written using Visual Studio 2010 and .NET 4.

Let me know if you have any features requests or find serious bugs.

Click here to download.

Scraping web pages automatically with C#

I frequently find myself writing small applications to scrape a web page to track a package, keep tabs on a product price, etc. I finally broke down and wrote a generic .NET 4 C# application that will do this for me via and XML "task" file. I execute the console application via the Windows Task Manager each day.

Your task file can include as many tasks (page scrapes) as you want and the application will notify you (via email) when it finds a successful comparison.

The magic works by you providing a web page URL to visit, a regular expression to find a pattern on the page, and a value to compare that pattern against. You can be notified when that pattern is different, is the same, or when it changes. The console application is full of nice little features that are configured via the task XML file.

Remember, this requires .NET 4.

See the default "HowToUse.htm" and the "tasks.xml" file for help on getting started. The example task file notifies you if your external IP address changes.

Let me know if you find any bugs are have a feature wish!

Download here (just three files and no install to perform)

Favorite Visual Studio 2010 Extensions

My favorite extensions for Visual Studio 2010...

Productivity Power Tools
If you are not using this, you have start! This has got all kinds of great extensions that really make your coding experience better.

AutoScroller
So I can click the middle mouse button and perform auto-scrolling.

Using HTTPS for WCF in Windows Service

These are instructions on how to use HTTPS in a Windows Service application hosting a WCF web service. The steps are a consolidation of information provided by Microsoft at:
http://msdn.microsoft.com/en-us/library/ms733791.aspx

I've tried to keep this as simple as possible.

1. Set the endpoint of your application to HTTPS (i.e. your app.config file). Note that if you are going to use a root certificate that is for your COMPUTER, your endpoint will need to match your computer name…not “localhost”. Example:
   https://mycomputername:9010/mywebservice
2. Verify HTTPS is not already configured by viewing ports configured for HTTPS (admin privs required):
   C:> netsh http show sslcert
3. Generate an application guid; any guid will do. This can be done from a computer with Visual Studio tools installed. Example:
   C:> uuidgen
   429d0213-340b-44db-991e-1c0c1ed3d91f
4. Find the thumbprint value for a machine/computer certificate in Personal store on local machine. Remove the spaces from the thumbprint. Example:
   b41dad508c2025eabe10f7d88b2c9a66983f950d
5. Register the certificate for whatever port you want (any IP address=0.0.0.0), using the thumbprint and guid (admin privs):
   C:> netsh http add sslcert ipport=0.0.0.0:9010 certhash=b51dad508c2025eabe10f7d88b2c9a66983f950d appid={429d0213-340b-44db-991e-1c0c1ed3d91f}
6. Verify the port is configured for HTTPS (admin privs):
   C:> netsh http show sslcert
7. To remove HTTPS for a port use the following:
   C:> Netsh http delete sslcert ipport=0.0.0.0:9010

AnkhSVN - Subversion Support for Visual Studio

I've started using AnkhSVN for Visual Studio 2010 on some of my hobby projects and have been quite happy with it. You'll still need base SVN to create and manage your repositories, but I'd recommend AnkhSVN!

You can download it here.
http://ankhsvn.open.collab.net/

AnkSVN integrates nicely with Beyond Compare!

Entity Framework: How to log generated SQL in ASP.NET

If you want to log/view the generated T-SQL from your Entity Framework context instances to the output window in Visual Studio create a TextWriter derivation and use it like so:

using (MyEntityContext db = new MyEntityContext())
{
  db.Log = new OutputDebugWriter();
  ...
}

class OutputDebugWriter : System.IO.TextWriter
{
   public override void Write(char[] buffer, int index, int count)
   {
      System.Diagnostics.Debug.Write(new string(buffer, index, count));
   }

   public override void Write(string value)
   {
      System.Diagnostics.Debug.Write(value);
   }

   public override Encoding Encoding
   {
      get { return System.Text.Encoding.Default; }
   }
}

Wake-on-LAN using C#

I recently set my personal computer to sleep after 30 minutes of inactivity. This seemed reasonable since I was normally only on the computer for a few hours a day.

I quickly realized that when I tried to remote desktop into it, if the computer was asleep it wouldn't connect (duh). I then modified the network interface settings to Wake-on-LAN and enhanced the security a bit by only waking on a "magic packet".

Then I wrote a interface where I can visit a web page and send the "magic packet" to my computer in order to wake it up. I won't go into the whole interface, but the code below demonstrates how to send the "magic packet" from C#. See the wiki article on details about what the "magic packet" is:

http://en.wikipedia.org/wiki/Wake-on-LAN

Also, don't forget to open any inbound or outbound ports on your firewall!

private void SendMagicPacket(string destinationHost, int destinationPort)
{
   // the header frame of 6 bytes of 255
   List<byte> datagram = new List<byte> { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

   // load the mac address (for demo purposes, set it to zeros)
   byte[] macAddress = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

   // 16 sequences of the MAC address
   for (int i = 0; i < 16; ++i)
   {
      datagram.AddRange(macAddress);
   }

   //
   // you don't have to do both below, but both are shown
   //

   // send directly to an IP address
   using (UdpClient client = new UdpClient())
   {
      client.Connect(destinationHost, destinationPort);
      client.Send(datagram.ToArray(), datagram.Count);
   }

   // broadcast it
   using (UdpClient client = new UdpClient())
   {
      client.Connect(IPAddress.Broadcast, destinationPort);
      client.Send(datagram.ToArray(), datagram.Count);
   }
}

Global.asax and precompiled web sites (aspnet_compiler.exe)

I recently deployed a precompiled VS 2010 (.NET 4) website using the aspnet_compiler. For the most part the site would start, but certain things would cause an exception when accessing objects in the Application object (which are initialized in the Application_Start of Global.asax.cs).

It turns out the issue was I didn't deploy the "precompiledApp.config" file that had been generated. For whatever reason, if you don't deploy this file, one of the things that occurs is the code of your Global.asax.cs isn't executed.

Lesson learned...always deploy the precompiledApp.config file.

Visual Studio 2010 Pro Power Tools

I recently installed the Microsoft VS 2010 Pro Power Tools. You won't be disappointed in the many cool things it adds to Visual Studio 2010.

Visit Microsoft here to download.

Just a few of the items I really like:

• Totally new window/tab interface with color-coding and sorting
• Current line highlighting (finally!)
• Move current line up or down with Alt-Up/Down arrow
• Triple-click to select entire line
• Syntax highlighting in method intellisense

Definitely download and give this a whirl! You won't be disappointed.