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PermissionSet Class

Represents a collection that can contain many different types of permissions.

Namespace:  System.Security
Assembly:  mscorlib (in mscorlib.dll)

[StrongNameIdentityPermissionAttribute(SecurityAction.InheritanceDemand, Name = "mscorlib", 
	PublicKey = "0x00000000000000000400000000000000")]
public class PermissionSet : ISecurityEncodable, 
	ICollection, IEnumerable, IStackWalk, IDeserializationCallback

You can use PermissionSet to perform operations on several different permissions as a group.

The following code example demonstrates the use of the PermissionSet class and members.

// This sample demonstrates the use of the PermissionSet class. 

using System;
using System.Reflection;
using System.Security.Permissions;
using System.Security;
using System.IO;
using System.Collections;

class MyClass
    public static void PermissionSetDemo()
        Console.WriteLine("Executing PermissionSetDemo");
            // Open a new PermissionSet.
            PermissionSet ps1 = new PermissionSet(PermissionState.None);
            Console.WriteLine("Adding permission to open a file from a file dialog box.");
            // Add a permission to the permission set.
                new FileDialogPermission(FileDialogPermissionAccess.Open));
            Console.WriteLine("Demanding permission to open a file.");
            Console.WriteLine("Demand succeeded.");
            Console.WriteLine("Adding permission to save a file from a file dialog box.");
                new FileDialogPermission(FileDialogPermissionAccess.Save));
            Console.WriteLine("Demanding permission to open and save a file.");
            Console.WriteLine("Demand succeeded.");
            Console.WriteLine("Adding permission to read environment variable USERNAME.");
                new EnvironmentPermission(EnvironmentPermissionAccess.Read, "USERNAME"));
            Console.WriteLine("Demand succeeded.");
            Console.WriteLine("Adding permission to read environment variable COMPUTERNAME.");
                new EnvironmentPermission(EnvironmentPermissionAccess.Read,
            // Demand all the permissions in the set.
            Console.WriteLine("Demand all permissions.");
            Console.WriteLine("Demand succeeded.");
            // Display the number of permissions in the set.
            Console.WriteLine("Number of permissions = " + ps1.Count);
            // Display the value of the IsSynchronized property.
            Console.WriteLine("IsSynchronized property = " + ps1.IsSynchronized);
            // Display the value of the IsReadOnly property.
            Console.WriteLine("IsReadOnly property = " + ps1.IsReadOnly);
            // Display the value of the SyncRoot property.
            Console.WriteLine("SyncRoot property = " + ps1.SyncRoot);
            // Display the result of a call to the ContainsNonCodeAccessPermissions method. 
            // Gets a value indicating whether the PermissionSet contains permissions 
            // that are not derived from CodeAccessPermission. 
            // Returns true if the PermissionSet contains permissions that are not 
            // derived from CodeAccessPermission; otherwise, false.
            Console.WriteLine("ContainsNonCodeAccessPermissions method returned " +
            Console.WriteLine("Value of the permission set ToString = \n" + ps1.ToString());
            PermissionSet ps2 = new PermissionSet(PermissionState.None);
            // Create a second permission set and compare it to the first permission set.
                new EnvironmentPermission(EnvironmentPermissionAccess.Read, "USERNAME"));
                new EnvironmentPermission(EnvironmentPermissionAccess.Write, "COMPUTERNAME"));
            IEnumerator list =  ps1.GetEnumerator();
            Console.WriteLine("Permissions in first permission set:");
            while (list.MoveNext())
            Console.WriteLine("Second permission IsSubsetOf first permission = " + ps2.IsSubsetOf(ps1));
            // Display the intersection of two permission sets.
            PermissionSet ps3 = ps2.Intersect(ps1);
            Console.WriteLine("The intersection of the first permission set and "
                + "the second permission set = " + ps3.ToString());
            // Create a new permission set.
            PermissionSet ps4 = new PermissionSet(PermissionState.None);
                new FileIOPermission(FileIOPermissionAccess.Read,
                new FileIOPermission(FileIOPermissionAccess.Read |
                FileIOPermissionAccess.Write | FileIOPermissionAccess.Append,
            // Display the union of two permission sets.
            PermissionSet ps5 = ps3.Union(ps4);
            Console.WriteLine("The union of permission set 3 and permission set 4 = "
                + ps5.ToString());
            // Remove FileIOPermission from the permission set.
            Console.WriteLine("The last permission set after removing FileIOPermission = "
                + ps5.ToString());
            // Change the permission set using SetPermission.
            ps5.SetPermission(new EnvironmentPermission(EnvironmentPermissionAccess.AllAccess, "USERNAME"));
            Console.WriteLine("Permission set after SetPermission = " + ps5.ToString());
            // Display result of ToXml and FromXml operations.
            PermissionSet ps6 = new PermissionSet(PermissionState.None);
            Console.WriteLine("Result of ToFromXml = " + ps6.ToString() + "\n");
            // Display results of PermissionSet.GetEnumerator.
            IEnumerator psEnumerator = ps1.GetEnumerator();
            while (psEnumerator.MoveNext())
            // Check for an unrestricted permission set.
            PermissionSet ps7 = new PermissionSet(PermissionState.Unrestricted);
            Console.WriteLine("Permission set is unrestricted = " + ps7.IsUnrestricted());
            // Create and display a copy of a permission set.
            ps7 = ps5.Copy();
            Console.WriteLine("Result of copy = " + ps7.ToString());
        catch (Exception e)


    static void Main(string[] args)


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0