This documentation is archived and is not being maintained.

GacMembershipCondition Class

Determines whether an assembly belongs to a code group by testing its global assembly cache membership. This class cannot be inherited.

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

'Declaration
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public NotInheritable Class GacMembershipCondition _
	Implements IMembershipCondition, ISecurityEncodable, ISecurityPolicyEncodable
'Usage
Dim instance As GacMembershipCondition

All assemblies installed in the global assembly cache are granted the FullTrust permission set.

The following example demonstrates the use of the GacMembershipCondition class.

Imports System
Imports System.Security
Imports System.Security.Policy
Imports System.Collections

Public Class GacMembershipConditionDemo

    ' Demonstrate the Copy method, which creates an identical  
    ' copy of the current permission. 
    Private Function CopyDemo() As Boolean
        Console.WriteLine( _
            "*************************************************************")
        Dim Gac1 As New GacMembershipCondition
        Console.WriteLine("Original membership condition = ")
        Console.WriteLine(Gac1.ToXml().ToString())
        Try 
            Dim membershipCondition As IMembershipCondition = Gac1.Copy()
            Console.WriteLine("Result of Copy = ")
            Console.WriteLine(CType(membershipCondition, _
                GacMembershipCondition).ToXml().ToString())
        Catch e As Exception
            Console.WriteLine(("Copy failed : " & Gac1.ToString() & _
                e.ToString()))
            Return False 
        End Try 

        Return True 
    End Function 'CopyDemo

    ' Demonstrate the Check method, which determines whether the specified  
    ' evidence satisfies the membership condition. 
    Private Function CheckDemo() As Boolean
        Console.WriteLine( _
            "*************************************************************")
        Dim Gac1 As New GacMembershipCondition
        Dim myGac As New GacInstalled
        Try 
            Dim hostEvidence() As Object = {myGac}
            Dim assemblyEvidence() As Object

            Dim myEvidence As New Evidence(hostEvidence, assemblyEvidence)
            Dim retCode As Boolean = Gac1.Check(myEvidence)
            Console.WriteLine(("Result of Check = " & retCode.ToString() _
                & ControlChars.Lf))
        Catch e As Exception
            Console.WriteLine(("Check failed : " & Gac1.ToString() & _ 
                e.ToString()))
            Return False 
        End Try 
        Return True 
    End Function 'CheckDemo

    ' Demonstrate the GetHashCode method, which returns a hash code 
    ' for the specified membership condition. 
    Private Function GetHashCodeDemo() As Boolean
        Console.WriteLine( _
            "*************************************************************")
        Dim Gac1 As New GacMembershipCondition
        Try
            Console.WriteLine( _
                ("Result of GetHashCode for a GacMembershipCondition = " _
                & Gac1.GetHashCode().ToString() & ControlChars.Lf))
        Catch e As Exception
            Console.WriteLine(("GetHashCode failed : " & _
                Gac1.ToString() & e.ToString()))
            Return False 
        End Try 

        Return True 
    End Function 'GetHashCodeDemo

    'Demonstrate the ToXml and FromXml methods, including the overloads.  
    ' ToXml creates an XML encoding of the membership condition and its  
    ' current state; FromXml reconstructs a membership condition with the  
    ' specified state from the XML encoding. 
    Private Function ToFromXmlDemo() As Boolean
        Console.WriteLine( _
            "*************************************************************")
        Try 
            Dim Gac1 As New GacMembershipCondition
            Dim Gac2 As New GacMembershipCondition

            ' Roundtrip a GacMembershipCondition to and from an XML encoding.
            Gac2.FromXml(Gac1.ToXml())
            Dim result As Boolean = Gac2.Equals(Gac1)
            If result Then
                Console.WriteLine(("Result of ToXml() = " & _ 
                    Gac2.ToXml().ToString()))
                Console.WriteLine(("Result of ToFromXml roundtrip = " & _ 
                    Gac2.ToString()))
            Else
                Console.WriteLine(Gac2.ToString())
                Console.WriteLine(Gac1.ToString())
                Return False 
            End If 

            Dim Gac3 As New GacMembershipCondition
            Dim Gac4 As New GacMembershipCondition
            Dim policyEnumerator As IEnumerator = _
                SecurityManager.PolicyHierarchy()
            While policyEnumerator.MoveNext()
                Dim currentLevel As PolicyLevel = _
                    CType(policyEnumerator.Current, PolicyLevel)
                If currentLevel.Label = "Machine" Then
                    Console.WriteLine(("Result of ToXml(level) = " & _
                        Gac3.ToXml(currentLevel).ToString()))
                    Gac4.FromXml(Gac3.ToXml(), currentLevel)
                    Console.WriteLine(("Result of FromXml(element, level) = " _
                        & Gac4.ToString()))
                End If 
            End While 
        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 Copy demo.
        tempReturnCode = CopyDemo()
        If tempReturnCode = True Then
            Console.Out.WriteLine("Copy demo completed successfully.")
        Else
            Console.Out.WriteLine("Copy demo failed.")
        End If

        returnCode = tempReturnCode AndAlso returnCode

        ' Call the Check demo.
        tempReturnCode = CheckDemo()
        If tempReturnCode = True Then
            Console.Out.WriteLine("Check demo completed successfully.")
        Else
            Console.Out.WriteLine("Check demo failed.")
        End If

        returnCode = tempReturnCode AndAlso returnCode

        ' Call the GetHashCode demo.
        tempReturnCode = GetHashCodeDemo()
        If tempReturnCode = True Then
            Console.Out.WriteLine("GetHashCode demo completed successfully.")
        Else
            Console.Out.WriteLine("GetHashCode demo failed.")
        End If

        returnCode = tempReturnCode AndAlso returnCode

        ' Call the ToFromXml demo.
        tempReturnCode = ToFromXmlDemo()
        If tempReturnCode = True 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 GacMembershipConditionDemo
            Dim returnCode As Boolean = testcase.RunDemo()
            If returnCode Then
                Console.Out.WriteLine( _
                    "The GacMembershipCondition 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 GacMembershipCondition 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 'GacMembershipConditionDemo

System.Object
  System.Security.Policy.GacMembershipCondition

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
Show: