How to create an aspect checking for null references on all methods in a class in postsharp

How to create an aspect checking for null references on all methods in a class in postsharp.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace test
{
    [MethodParameterNullCheck]
    internal class Class
    {
     public Class()
     {

     }

     public void MethodA(int i, ClassA a, ClassB b)
     {
              //Some business logic
     }
    }
}

The aspect [MethodParameterNullCheck] should then unfold to the following code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace test
{
    [MethodParameterNullCheck]
    internal class Class
    {
     public Class()
     {

     }

     public void MethodA(int i, ClassA a, ClassB b)
     {
      if (a == null) throw new ArgumentNullException("Class->MethodA: Argument a of ClassA is not allowed to be null.");
      if (b == null) throw new ArgumentNullException("Class->MethodA: Argument b of ClassB is not allowed to be null.");
      // Some Business Logic
     }
    }
}

I will appreciate if you can give me a sample implementation on this to get me startet on AOP with postsharp.

From stackoverflow

• An alternative approach is an extension method:

  public static void ThrowIfNull<T>(this T obj, string parameterName) where T : class
  {
      if(obj == null) throw new ArgumentNullException(parameterName);
  }
  

  then call:

  foo.ThrowIfNull("foo");
  bar.ThrowIfNull("bar");
  

  The T : class pervents us accidentally boxing ints etc.

  Re AOP; Jon Skeet has a sample for something similar here - but covering a single method/parameter.

  Here's the aspect reproduced; note that this aspect covers only 1 argument at a time, and is method-specific, but in general I'd argue that this is perfectly reasonable... however, you could probably change it.

  using System;
  using System.Reflection;
  using PostSharp.Laos;
  
  namespace IteratorBlocks
  {
      [Serializable]
      class NullArgumentAspect : OnMethodBoundaryAspect
      {
          string name;
          int position;
  
          public NullArgumentAspect(string name)
          {
              this.name = name;
          }
  
          public override void CompileTimeInitialize(MethodBase method)
          {
              base.CompileTimeInitialize(method);
              ParameterInfo[] parameters = method.GetParameters();
              for (int index = 0; index < parameters.Length; index++)
              {
                  if (parameters[index].Name == name)
                  {
                      position = index;
                      return;
                  }
              }
              throw new ArgumentException("No parameter with name " + name);
          }
  
          public override void OnEntry(MethodExecutionEventArgs eventArgs)
          {
              if (eventArgs.GetArguments()[position] == null)
              {
                  throw new ArgumentNullException(name);
              }
          }
      }
  }