Using an expression to determine the name of a parameter.

Expression.cs

using System;
using System.Linq.Expressions;

namespace ConsoleApplication1
{
	public static class Assert
	{
		public static T NotNull<T>(Expression<Func<T>> expression) where T : class
		{
			if (expression.Body == null || expression.Body.NodeType != ExpressionType.MemberAccess)
				throw new ArgumentException("Expression is not in the correct format.");

			var memberExpression = expression.Body as MemberExpression;

			if (memberExpression == null)
				throw new ArgumentException("Expression is not in the correct format.");

			var name = memberExpression.Member.Name;
			var value = expression.Compile().Invoke();

			if (value == null)
			{
				throw new ArgumentNullException(name);
			}

			return value;
		}
	}


	public class Example
	{
		private object _dependency1;
		private object _dependency2;
		public Example(object dependency1, object dependency2)
		{
			_dependency1 = Assert.NotNull(() => dependency1);
			_dependency2 = Assert.NotNull(() => dependency2);
		}
	}

	class Program
	{
		static void Main(string[] args)
		{
			var x = new Example(new object(), null);
		}
	}
}

This sample will throw an exception ArgumentNullException. Value cannot be null. Paramater name: dependency2.

The name dependency2 is the name of the parameter to the method.