.NET Framework Standard Library Annotated Reference, Volume 1: Base Class Library and Extended Numerics Library

Example

using System;
using System.Security;
using System.Security.Permissions;

namespace Samples
{

  public class SecurityExceptionSample
  {
    [EnvironmentPermissionAttribute(
                SecurityAction.PermitOnly,
                Read="USERNAME")]
    static void Main(string[] args)
    {
      string s = "COMPUTERNAME";
      try
      {
        Console.WriteLine("Variable {0} Value: {1}", s,
                Environment.GetEnvironmentVariable(s));
      }
      catch(SecurityException e)
      {
        Console.WriteLine("Exception {0}", e);
      }
    }
  }
}

The output is:

Exception System.Security.SecurityException: Request for the permission of type System
.Security.Permissions.EnvironmentPermission, mscorlib, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 ...