File Directory Stream C# Tutorial

using System;
using System.IO;
using System.Security.Permissions;
[assembly:FileIOPermissionAttribute(SecurityAction.RequestRefuse,Unrestricted=true)]
class MainClass
{
  public static void Main() 
  {
    FileStream fsOut = File.Create(@"c:\\temp\\test.txt");
    StreamWriter sw = new StreamWriter(fsOut);
    sw.WriteLine("str");
    sw.Flush();
    sw.Close();
  }
}
Unhandled Exception: System.Security.SecurityException: Request for the permission of type 'System.S
ecurity.Permissions.FileIOPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77
a5c561934e089' failed.
at System.Security.CodeAccessSecurityEngine.Check(Object demand, StackCrawlMark& stackMark, Boole
an isPermSet)
at System.Security.CodeAccessPermission.Demand()
at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean
useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, St
ring msgPath, Boolean bFromProxy)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int
32 bufferSize, FileOptions options)
at MainClass.Main()
The action that failed was:
Demand
The type of the first permission that failed was:
System.Security.Permissions.FileIOPermission
The first permission that failed was:
The demand was for:
The granted set of the failing assembly was:
The refused set of the failing assembly was:
The assembly or AppDomain that failed was:
main, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null
The method that caused the failure was:
Void Main()
The Zone of the assembly that failed was:
MyComputer
The Url of the assembly that failed was:
file:///C:/Java_Dev/WEB/dev/CSharp/main.exe