Request for the permission of type 'System.Net.SocketPermission,  System, Version=4.0.0.0, Culture=neutral,  PublicKeyToken=b77a5c561934e089' failed.

In order to fix this there are three solutions:

1. Instead of MySQL, use Microsoft SQL server.

2. Move to a hosting provider that supports a full trust environment or get your own server.

3. Ask your hosting provider to update the medium trust policy with SocketPermission. The steps will be explained here:

Open the following file in a text editor:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\web_mediumtrust.config

Or when you are running 64 bit:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\web_mediumtrust.config

Inside the SecurityClasses tag, add the following line:

<SecurityClass Name="SocketPermission" Description="System.Net.SocketPermission, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>

Scroll down and look for the following PermissionSet:

<PermissionSet version="1" Name="ASP.Net">

Add the following inside this PermissionSet:

<IPermission class="SocketPermission" version="1" Unrestricted="true" />

That’s all, a restart of IIS is, as far as I know, not necessary.

First thing you need to do is add a log4net section in your web.config if you don’t have one yet.

<configSections>
 ...
 <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net"/>
 ...
</configSections>

Then add the log4net section, and configure an appender and logger.

<log4net>
 <appender name="DebugSQL" type="log4net.Appender.TraceAppender">
 <layout type="log4net.Layout.PatternLayout">
 <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
 </layout>
 </appender>
 
 <logger name="NHibernate.SQL" additivity="false">
 <level value="DEBUG"/>
 <appender-ref ref="DebugSQL" />
 </logger>
</log4net>

That’s all. Don’t forget to configure log4net in the Global.asax.

protected void Application_Start()
{
 log4net.Config.XmlConfigurator.Configure();
 ...
}

In this window select your MIDI Controller inputs in the MIDI Inputs list. Press Ok and go to View → Input Monitor to view the MIDI input of your controller.

For all buttons and keys on your controller the MIDI note is listed in the NOTE column. Unfortunately when using the knobs and sliders on my Digital Jockey 2 no information was shown about the channel used. Please post a comment if you know how to extract this information or if there are better tools to view MIDI data.

The first thing to do is create a new user.  Go to Start and click with the right mouse button on Computer and choose Manage from the submenu. In the left column choose Local Users and Groups and open the Users folder. Now create a new user (Action → New User or right mouse button → New User):

Click Create and close the window. The next thing to do is change the permission of your music folder:

1. Open Properties of your music folder
2. Open the Security tab and press the Edit button
3. In the Permissions window, choose Add
4. Enter the name of your Traktor user and press OK
5. Make sure the Traktor user is selected and in the permissions list check Deny for the Write permission

The final step is running Traktor as the newly created user. To do so go to Start and navigate to the Traktor shortcut. Now hold Shift and right click on the shortcut. Choose Run as different user and enter the Trakor user credentials. Since you start Traktor using a different user you need to reconfigure the application, but Traktor has no permission to modify your files any more.

Now startup LEd. In order to create a new paper go to File → New and on the Template tab choose Paper. In the file tree, open your .tex file. You will see something like this:

\documentclass{article}
 
\title{...}
\author{...}
\date{...}
 
\begin{document}
\maketitle
 
\section{...}
 
\section{...}
 
\end{document}

You can change the dots for anything you like and add text under the \section tags:

\section{Introduction}
Lorem ipsum dolor sit amet...

Now it’s time to compile the LaTeX document; press the green arrow button in the toolbar or F9. Press the blue arrow or F7 to create a PDF file (the file is stored in the same folder as your .tex file):

In scientific papers it’s quite common to refer to other papers. In order to manage this we use BibTeX. First create a .bib file adding a new file to the project: File → New and choose “Bibliography file in BibTeX format”. Name the file for example mybib and make sure to add it to the right project. Add the following example text to your .bib file:

@article{miles09,
 author = {Richard Miles},
 title = {Who is John Doe?},
 year = {2009},
 journal = {The Unknown Magazine},
 volume = {1},
 number = {1},
 pages = {20--42}
}

In your .tex file, add the following commands before the \end{document} tag to enable the bibliography:

\bibliographystyle{plain}
\bibliography{mybib}

Now if you want to cite something simply type \cite and a window will popup containing all the entries in your bibliography:

Lorem ipsum dolor sit amet, consectetur adipiscing elit. \cite{miles09}

Compile the bibliography file by pressing the blue book icon or F6. Then compile your LaTeX file and create a PDF. As you can see the bibliography is included in your document:

That’s all for now, for more information about the BibTeX format see this page. Enjoy LaTeX!

The first step is download and install the latest version of NUnit since older versions are not compatible with .NET 4. NUnit version 2.5.5 can be downloaded here.

Now go to Tools -> External Tools:

I think this screen shot explains itself very well. Now its possible to add this external command to a tool bar. To do so go to View -> Toolbars -> Customize:

Press the New button and enter a name. Now open the Commands tab and add the external command (usually External Command 1 when you don’t have any other external commands) to the toolbar:

When clicking the NUnit button in the new toolbar the NUnit GUI starts and loads your test suite.

Implicit conversion

Implicit conversion (or coercion) is automatic type conversion by the compiler. In C# it does not require a special syntax because the type conversion is safe and no data will be lost. In the following example the value of an integer is stored in a long. This is safe because an integer is 4 bytes (on a 32 bit computer), and a long is 8 bytes. So every value that fits in an integer fits in a long. For a complete conversion table see this page.

int i = 12345678;
long l = i;

It is also possible to cast a derived class to a base class without using a special syntax.

Explicit conversion

Instead of implicit conversion explicit conversion (or casting) is not done by the compiler. It is explicitly defined in the application (i.e. it requires a cast operator). There is a possible risk of losing data when the source and destination have a different size or when the source is converted to a base class. Example:

double d = 10.345;
int i = (int)d;

This example will not compile without the explicit cast operator since a double fits not in an integer. Also the value will lose its precision since an integer does not store decimal values. On this page you can find an explicit number conversion table.

User-defined conversion

In C# it is possible to create your own methods for implicit and explicit conversion. For more information see this article.

Helper functions

The .NET framework has various helper functions for conversion. For example System.Convert and the Parse method of various types (e.g. Int32.Parse).

Boxing and unboxing

C# provides a unified type system. All types are derived from the type “object”. It is possible to convert for example an integer to the type object (boxing) and back (unboxing). The is keyword checks if an object is compatible with a specific type. Example:

class Program
{
 static void Main(string[] args)
 {
  int i = 10;
  object o = i; // boxing
  int j = (int) o; // unboxing
  Console.WriteLine(j);
  if (o is int)
  {
   Console.WriteLine("o is an int");
  }
  Console.ReadKey();
 }
}

“Cast” versus “as”

The as operator is often used for type conversion, and it works more or less the same as the cast prefix:

class Program
{
 public class ClassA { }
 
 static void Main(string[] args)
 {
  ClassA a = new ClassA();
  object o = a;
 
  ClassA a2 = (ClassA)o;
  ClassA a3 = o as ClassA;
 }
}

The difference between these two types of conversion is that the first will throw an exception and the second will return null when the conversion is incorrect:

class Program
{
 public class ClassA { }
 
 static void Main(string[] args)
 {
  int i = 5;
  object o = i;
 
  try
  {
   ClassA a2 = (ClassA)o;
  }
  catch (InvalidCastException ex)
  {
   Console.WriteLine(ex.Message);
  }
 
  ClassA a3 = o as ClassA;
  if (a3 == null)
  {
   Console.WriteLine("Incorrect conversion");
  }
  Console.ReadKey();
 }
}

However, this is not the only difference (see this post by Eric Lippert). When you have a user-defined conversion from class A to B, the cast operator (B)A will run the user-defined conversion while the “as” operator will not. The “as” operator will only consider reference, boxing and unboxing conversions. Like Eric says:

• As: “I don’t know if this conversion is legal or not; we’re going to give it a try and see how it goes.”
• Cast: “I am certain that this conversion is legal and I am willing to take a runtime exception if I’m wrong.”
• As: “I want to know what this object *really is*, not what it is convertible to by some representation-changing specially-defined conversion rule.”
• Cast: “Convert this thing using whatever crazy mechanism you need to do to make it work.”

Performance

This article by Emilio Guijarro gives a good explanation about performance of the cast and “as” operator. He concludes the “as” operator is about 5 times faster than the cast operator. The performance is only going to matter in the million number of casts, and then the performance problem is probably why you need so many cast operations.

Why (not) to use “as”

As said before the “as” operator returns null when the conversion is incorrect. When using this piece of code you can not check if the original object was null:

class Program
{
 public class ClassA { }
 
 static void Main(string[] args)
 {
  ClassA a = null;
  object o = a;
 
  try
  {
   ClassA a2 = (ClassA)o;
  }
  catch (InvalidCastException ex)
  {
   Console.WriteLine(ex.Message);
  }
 
  ClassA a3 = o as ClassA;
  if (a3 == null)
  {
   Console.WriteLine("Incorrect conversion");
  }
  Console.ReadKey();
 }
}

This program will write “Incorrect conversion” while the cast conversion didn’t throw an exception. Also the “is” operator does not help in this case since it returns false when the object is null. A correct pattern could be:

if (o == null)
{
 Console.WriteLine("object is null");
}
else
{
 ClassA a3 = o as ClassA;
 if (a3 == null)
 {
  Console.WriteLine("Incorrect conversion");
 }
}

References

• Casting and type conversion – MSDN
• Boxing and unboxing in C# – C-Sharpcorner
• Difference between “as” and “cast” operators – Eric Lippert

Rhino.Mocks.Exceptions.ExpectationViolationException : IMyInterface.MyVoidFunction; Expected #0, Actual #1.

using (_mock.Record())
{
  Expect.Call(_myMock.GetValue("a")).Return("b");
  /* insert expectation for void function here */
}
 
using (_mock.Playback())
{
  // DoSomething calls the mocked object's GetValue function, which returns 'b' when the parameter is 'a'
  // DoSomething also calls a void function which is located in the interface of the mocked object, so this
  // void function must be mocked too, else the test run will fail
  Assert.AreEqual("b", _myObject.DoSomething("a"));
}

When trying to create an expectation for this void function Visual Studio will give a syntax error:

Expect.Call(_myMock.MyVoidFunction()); // Argument '1': cannot convert from 'void' to 'Rhino.Mocks.Expect.Action'

On the internet I found two solutions to fix this problem. The first solution uses a delegate:

Expect.Call(delegate{ _myMock.MyVoidFunction(); });

The second solution uses a lambda:

Expect.Call(() => _myMock.MyVoidFunction());

Now the test will succeed.