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GacIdentityPermission Class

Defines the identity permission for files originating in the global assembly cache. This class cannot be inherited.

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

'Declaration
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public NotInheritable Class GacIdentityPermission
	Inherits CodeAccessPermission
'Usage
Dim instance As GacIdentityPermission

/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
public final class GacIdentityPermission extends CodeAccessPermission
SerializableAttribute 
ComVisibleAttribute(true) 
public final class GacIdentityPermission extends CodeAccessPermission
Not applicable.

Files are either in the global assembly cache, or they are not. There are no variations to the permission granted, so all GacIdentityPermission objects are equal.

NoteImportant:

In the .NET Framework versions 1.0 and 1.1, demands on the identity permissions are effective even when the calling assembly is fully trusted. That is, although the calling assembly has full trust, a demand for an identity permission fails if the assembly does not meet the demanded criteria. In the .NET Framework version 2.0, demands for identity permissions are ineffective if the calling assembly has full trust. This assures consistency for all permissions, eliminating the treatment of identity permissions as a special case.

The following code example shows the behavior of the GacIdentityPermission class methods.

NoteNote:

The code example is intended to show the behavior of the methods, not to demonstrate their use. In general, the methods of permission classes are used by the security infrastructure; they are not typically used in applications. Generally, only the constructors are used in application code. The created instance validates or controls resource access by using inherited CodeAccessPermission methods such as Demand.

Imports System
Imports System.Security
Imports System.Security.Permissions
Imports Microsoft.VisualBasic



Public Class GacIdentityPermissionDemo

    ' IsSubsetOf determines whether the current permission is a subset of the specified permission.
    Private Function IsSubsetOfDemo() As Boolean
        Try
            Dim Gac1 As New GacIdentityPermission
            Dim Gac2 As New GacIdentityPermission(PermissionState.None)
            If (Gac1.Equals(Gac2)) Then
                Console.WriteLine("GacIdentityPermission() equals GacIdentityPermission(PermissionState.None).")
            End If
            If Gac1.IsSubsetOf(Gac2) Then
                Console.WriteLine((Gac1.ToString() & " is a subset of " & Gac2.ToString()))
            Else
                Console.WriteLine((Gac1.ToString() & " is not a subset of " & Gac2.ToString()))
            End If
        Catch e As Exception
            Console.WriteLine(("An exception was thrown : " & e.ToString().ToString()))
            Return False
        End Try
        Return True
    End Function 'IsSubsetOfDemo

    ' Union creates a new permission that is the union of the current permission 
    ' and the specified permission.
    Private Function UnionDemo() As Boolean
        Dim Gac1 As New GacIdentityPermission(PermissionState.None)
        Dim Gac2 As New GacIdentityPermission
        Try
            Dim p3 As GacIdentityPermission = CType(Gac1.Union(Gac2), GacIdentityPermission)

            If Not (p3 Is Nothing) Then
                Console.WriteLine("The union of two GacIdentityPermissions was successful.")

            Else
                Console.WriteLine("The union of two GacIdentityPermissions failed.")
                Return False
            End If
        Catch e As Exception
            Console.WriteLine(("An exception was thrown : " & e.ToString()))
            Return False
        End Try

        Return True
    End Function 'UnionDemo

    ' Intersect creates and returns a new permission that is the intersection of the 
    ' current permission and the specified permission.
    Private Function IntersectDemo() As Boolean
        Dim Gac1 As New GacIdentityPermission
        Dim Gac2 As New GacIdentityPermission
        Try
            Dim p3 As GacIdentityPermission = CType(Gac1.Intersect(Gac2), GacIdentityPermission)
            If Not (p3 Is Nothing) Then
                Console.WriteLine(("The intersection of the two permissions = " & p3.ToString() & ControlChars.Lf))

            Else
                Console.WriteLine("The intersection of the two permissions is null." & ControlChars.Lf)
            End If
        Catch e As Exception
            Console.WriteLine(("An exception was thrown : " & e.ToString()))
            Return False
        End Try

        Return True
    End Function 'IntersectDemo

    'Copy creates and returns an identical copy of the current permission.
    Private Function CopyDemo() As Boolean

        Dim Gac1 As New GacIdentityPermission
        Dim Gac2 As New GacIdentityPermission
        Console.WriteLine("**************************************************************************")
        Try
            Gac2 = CType(Gac1.Copy(), GacIdentityPermission)
            If Not (Gac2 Is Nothing) Then
                Console.WriteLine(("Result of copy = " & Gac2.ToString() & ControlChars.Lf))
            End If

        Catch e As Exception
            Console.WriteLine(("Copy failed : " & Gac1.ToString() & e.ToString()))
            Return False
        End Try

        Return True
    End Function 'CopyDemo

    ' ToXml creates an XML encoding of the permission and its current state; FromXml reconstructs a 
    ' permission with the specified state from the XML encoding. 
    Private Function ToFromXmlDemo() As Boolean
        Dim Gac1 As New GacIdentityPermission
        Dim Gac2 As New GacIdentityPermission
        Console.WriteLine("**************************************************************************")
        Try
            Gac2 = New GacIdentityPermission(PermissionState.None)
            Gac2.FromXml(Gac1.ToXml())
            Dim result As Boolean = Gac2.Equals(Gac1)
            If Gac2.IsSubsetOf(Gac1) AndAlso Gac1.IsSubsetOf(Gac2) Then
                Console.WriteLine(("Result of ToFromXml = " & Gac2.ToString()))
            Else
                Console.WriteLine(Gac2.ToString())
                Console.WriteLine(Gac1.ToString())
                Return False
            End If
        Catch e As Exception
            Console.WriteLine(("ToFromXml failed. " & e.ToString()))
            Return False
        End Try

        Return True
    End Function 'ToFromXmlDemo

    ' Invoke all demos.
    Public Function RunDemo() As Boolean

        Dim returnCode As Boolean = True
        Dim tempReturnCode As Boolean
        ' Call the IsSubsetOf demo.
        tempReturnCode = IsSubsetOfDemo()
        If tempReturnCode Then
            Console.Out.WriteLine("IsSubsetOf demo completed successfully.")
        Else
            Console.Out.WriteLine("Subset demo failed.")
        End If
        returnCode = tempReturnCode AndAlso returnCode

        ' Call the Union demo.
        tempReturnCode = UnionDemo()
        If tempReturnCode Then
            Console.Out.WriteLine("Union demo completed successfully.")
        Else
            Console.Out.WriteLine("Union demo failed.")
        End If
        returnCode = tempReturnCode AndAlso returnCode

        ' Call the Intersect demo.	
        tempReturnCode = IntersectDemo()
        If tempReturnCode Then
            Console.Out.WriteLine("Intersect demo completed successfully.")
        Else
            Console.Out.WriteLine("Intersect demo failed.")
        End If
        returnCode = tempReturnCode AndAlso returnCode


        ' Call the Copy demo.	
        tempReturnCode = CopyDemo()
        If tempReturnCode Then
            Console.Out.WriteLine("Copy demo completed successfully.")
        Else
            Console.Out.WriteLine("Copy demo failed.")
        End If
        returnCode = tempReturnCode AndAlso returnCode

        ' Call the ToFromXML demo.	
        tempReturnCode = ToFromXmlDemo()
        If tempReturnCode Then
            Console.Out.WriteLine("ToFromXML demo completed successfully.")
        Else
            Console.Out.WriteLine("ToFromXml demo failed.")
        End If
        returnCode = tempReturnCode AndAlso returnCode

        Return returnCode
    End Function 'RunDemo

    ' Test harness.
    Public Overloads Shared Sub Main(ByVal args() As [String])
        Try
            Dim testcase As New GACIdentityPermissionDemo
            Dim returnCode As Boolean = testcase.RunDemo()
            If returnCode Then
                Console.Out.WriteLine("The GacIdentityPermission demo completed successfully.")
                Console.Out.WriteLine("Press the Enter key to exit.")
                Dim consoleInput As String = Console.ReadLine()
                System.Environment.ExitCode = 100
            Else
                Console.Out.WriteLine("The GacIdentityPermission demo failed.")
                Console.Out.WriteLine("Press the Enter key to exit.")
                Dim consoleInput As String = Console.ReadLine()
                System.Environment.ExitCode = 101
            End If
        Catch e As Exception
            Console.Out.WriteLine("The GacIdentityPermission demo failed.")
            Console.WriteLine(e.ToString())
            Console.Out.WriteLine("Press the Enter key to exit.")
            Dim consoleInput As String = Console.ReadLine()
            System.Environment.ExitCode = 101
        End Try
    End Sub 'Main
End Class 'GacIdentityPermissionDemo




import System.* ;
import System.Security.* ;
import System.Security.Permissions.*;

public class GacIdentityPermissionDemo
{
    // IsSubsetOf determines whether the current permission is a subset 
    // of the specified permission.
    private boolean IsSubsetOfDemo()
    {
        try {
            GacIdentityPermission gac1 = new GacIdentityPermission();
            GacIdentityPermission gac2 = new GacIdentityPermission(
                PermissionState.None);
            if (gac1.Equals(gac2)) {
                Console.WriteLine("GacIdentityPermission() " 
                    + "equals GacIdentityPermission(PermissionState.None).");
            }

            if (gac1.IsSubsetOf(gac2)) {
                Console.WriteLine((gac1 + " is a subset of " + gac2));
            }
            else {
                Console.WriteLine((gac1 + " is not a subset of " + gac2));
            }
        }
        catch (System.Exception e) {
            Console.WriteLine(("An exception was thrown : " + e));
            return false;
        }
        return true;
    } //IsSubsetOfDemo

    // Union creates a new permission that is the union of the current 
    // permission and the specified permission.
    private boolean UnionDemo()
    {
        GacIdentityPermission gac1 = new GacIdentityPermission(
            PermissionState.None);

        GacIdentityPermission gac2 = new GacIdentityPermission();

        try {
            GacIdentityPermission p3 = 
                ((GacIdentityPermission)(gac1.Union(gac2)));
            if (p3 != null) {
                Console.WriteLine("The union of two GacIdentityPermissions " 
                    + "was successful.");
            }
            else {
                Console.WriteLine("The union of two " 
                    + "GacIdentityPermissions failed.");
                return false;
            }
        }
        catch (System.Exception e) {
            Console.WriteLine(("An exception was thrown : " + e));
            return false;
        }
        return true;
    } //UnionDemo

    // Intersect creates and returns a new permission that is the 
    // intersection of the current permission and the specified permission.
    private boolean IntersectDemo()
    {
        GacIdentityPermission gac1 = new GacIdentityPermission();
        GacIdentityPermission gac2 = new GacIdentityPermission();

        try {
            GacIdentityPermission p3 = 
                ((GacIdentityPermission)(gac1.Intersect(gac2)));
            if (p3 != null) {
                Console.WriteLine(("The intersection of the two permissions = " 
                    + p3.ToString() + "\n"));
            }
            else {
                Console.WriteLine("The intersection of the two permissions " 
                    + "is null.\n");
            }
        }
        catch (System.Exception e) {
            Console.WriteLine(("An exception was thrown : " + e));
            return false;
        }
        return true;
    } //IntersectDemo    

    // Copy creates and returns an identical copy of the current permission.
    private boolean CopyDemo()
    {
        GacIdentityPermission gac1 = new GacIdentityPermission();
        GacIdentityPermission gac2 = new GacIdentityPermission();
        Console.WriteLine("****************************************" 
            + "**********************************");
        
        try {
            gac2 = ((GacIdentityPermission)(gac1.Copy()));
            if (gac2 != null) {
                Console.WriteLine(("Result of copy = " 
                    + gac2.ToString() + "\n"));
            }
        }
        catch (System.Exception e) {
            Console.WriteLine(("Copy failed : " + gac1.ToString() + e));
            return false;
        }
        return true;
    } //CopyDemo

    // ToXml creates an XML encoding of the permission and its current state; 
    // FromXml reconstructs a permission with the specified state from the 
    // XML encoding.
    private boolean ToFromXmlDemo()
    {
        GacIdentityPermission gac1 = new GacIdentityPermission();
        GacIdentityPermission gac2 = new GacIdentityPermission();
        Console.WriteLine("***************************************" 
            + "***********************************");
        
        try {
            gac2 = new GacIdentityPermission(PermissionState.None);
            gac2.FromXml(gac1.ToXml());

            boolean result = gac2.Equals(gac1);

            if (gac2.IsSubsetOf(gac1) && gac1.IsSubsetOf(gac2)) {
                Console.WriteLine(("Result of ToFromXml = " + gac2.ToString()));
            }
            else {
                Console.WriteLine(gac2.ToString());
                Console.WriteLine(gac1.ToString());
                return false;
            }
        }
        catch (System.Exception e) {
            Console.WriteLine(("ToFromXml failed. " + e));
            return false;
        }
        return true;
    } //ToFromXmlDemo    

    // Invoke all demos.
    public boolean RunDemo()
    {
        boolean returnCode = true;
        boolean tempReturnCode;

        // Call the IsSubsetOf demo.
        if (tempReturnCode = IsSubsetOfDemo()) {
            Console.get_Out().WriteLine("IsSubsetOf demo " 
                + "completed successfully.");
        }
        else {
            Console.get_Out().WriteLine("Subset demo failed.");
        }
        returnCode = tempReturnCode && returnCode;

        // Call the Union demo.
        if (tempReturnCode = UnionDemo()) {
            Console.get_Out().WriteLine("Union demo completed successfully.");
        }
        else {
            Console.get_Out().WriteLine("Union demo failed.");
        }
        returnCode = tempReturnCode && returnCode;

        // Call the Intersect demo.
        if (tempReturnCode = IntersectDemo()) {
            Console.get_Out().WriteLine("Intersect demo " 
                + "completed successfully.");
        }
        else {
            Console.get_Out().WriteLine("Intersect demo failed.");
        }
        returnCode = tempReturnCode && returnCode;

        // Call the Copy demo.
        if (tempReturnCode = CopyDemo()) {
            Console.get_Out().WriteLine("Copy demo completed successfully.");
        }
        else {
            Console.get_Out().WriteLine("Copy demo failed.");
        }
        returnCode = tempReturnCode && returnCode;

        // Call the ToFromXML demo.
        if (tempReturnCode = ToFromXmlDemo()) {
            Console.get_Out().WriteLine("ToFromXML demo " 
                + "completed successfully.");
        }
        else {
            Console.get_Out().WriteLine("ToFromXml demo failed.");
        }
        returnCode = tempReturnCode && returnCode;
        return returnCode;
    } //RunDemo    

    // Test harness.
    public static void main(String[] args)
    {
        try {
            GacIdentityPermissionDemo testcase = 
                new GacIdentityPermissionDemo();
            boolean returnCode = testcase.RunDemo();
            if (returnCode) {
                Console.get_Out().WriteLine("The GacIdentityPermission demo " 
                    + "completed successfully.");
                Console.get_Out().WriteLine("Press the Enter key to exit.");
                String consoleInput = Console.ReadLine();
                System.Environment.set_ExitCode(100);
            }
            else {
                Console.get_Out().WriteLine("The GacIdentityPermission " 
                    + "demo failed.");
                Console.get_Out().WriteLine("Press the Enter key to exit.");
                String consoleInput = Console.ReadLine();
                System.Environment.set_ExitCode(101);
            }
        }
        catch (System.Exception e) {
            Console.get_Out().WriteLine("The GacIdentityPermission " 
                + "demo failed.");
            Console.WriteLine(e.ToString());
            Console.get_Out().WriteLine("Press the Enter key to exit.");
            String consoleInput = Console.ReadLine();
            System.Environment.set_ExitCode(101);
        }
    } //main
} //GacIdentityPermissionDemo

System.Object
   System.Security.CodeAccessPermission
    System.Security.Permissions.GacIdentityPermission

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

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

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