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

Example

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

namespace Samples
{
  public class UnauthorizedAccessExceptionConstructor
  {
    public static void Main()
    {
      try
      {
        string s = "readonly.txt";
        FileStream fs = File.OpenWrite(s);
      }
      catch(UnauthorizedAccessException e)
      {
        Console.WriteLine("Exception: {0}", e);
      }
    }
  }
}

The output is

 Exception: System.UnauthorizedAccessException: Access to the path "C:\Books\BCL\Samples\System\UnauthorizedAccessException\readonly.txt" is denied. at System.IO.__Error.WinIOError(Int32 errorCode, String str) at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean useAsync, String msgPath, Boolean bFromProxy) at System.IO.FileStream..ctor(String ...