EnvironmentPermission クラス

.NET Framework クラス ライブラリ リファレンス

EnvironmentPermission クラス

システム環境変数およびユーザー環境変数へのアクセスを制御します。このクラスは継承できません。

名前空間: System.Security.Permissions
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public NotInheritable Class
 EnvironmentPermission
    Inherits CodeAccessPermission
    Implements IUnrestrictedPermission

Visual Basic (使用法)

Dim instance As EnvironmentPermission

C#

[SerializableAttribute] 
[ComVisibleAttribute(true)] 
public sealed class EnvironmentPermission :
 CodeAccessPermission, IUnrestrictedPermission

C++

[SerializableAttribute] 
[ComVisibleAttribute(true)] 
public ref class EnvironmentPermission sealed
 : public CodeAccessPermission, IUnrestrictedPermission

J#

/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
public final class EnvironmentPermission extends
 CodeAccessPermission implements IUnrestrictedPermission

JScript

SerializableAttribute 
ComVisibleAttribute(true) 
public final class EnvironmentPermission extends
 CodeAccessPermission implements IUnrestrictedPermission

解説

環境変数名は、大文字と小文字を区別せずに、名前をセミコロンで区切った 1 つ以上のリストによって指定されます。指定した変数への読み取り用と書き込み用とで個別のリストを用意します。書き込みアクセスでは、既存の値を変更する上に、環境変数の作成および削除ができます。

注意
EnvironmentPermission は、環境変数とその値にアクセスするためのアクセス許可を与えます。環境変数とその値へのアクセスを拒否するには、同じ値を格納する他の変数へのアクセスも拒否する必要があります。たとえば、TMP 環境変数とその値 (%USERPROFILE%\Local Settings\Temp) へのアクセスを Deny によって拒否するには、TMP、TEMP を含め、この値にアクセスするために使用できるその他のすべての変数へのアクセスも Deny によって拒否する必要があります。複数のパスを使用する場合は、PermitOnly と Deny を組み合わせて使用することをお勧めします。この問題および PermitOnly と Deny の使用法の詳細については、「Deny メソッドの使用」の「Deny の使用による標準化の問題」を参照してください。

使用例

EnvironmentPermission メソッドの動作を示すコード例を次に示します。この例では、メソッドの使用方法ではなく、メソッドの結果を示すことを目的としています。

Visual Basic

Imports System
Imports System.Security
Imports System.Security.Permissions
Imports System.Collections


Public Class EnvironmentPermissionDemo
    
    ' IsSubsetOf determines whether the current permission is a subset
 of the specified permission.
    Private Function IsSubsetOfDemo() As
 Boolean 
        Dim returnValue As Boolean
 = True
        Dim envPerm1 As New
 EnvironmentPermission(EnvironmentPermissionAccess.Read, "windir")
        Dim envPerm2 As New
 EnvironmentPermission(EnvironmentPermissionAccess.AllAccess, "TEMP")
        If envPerm1.IsSubsetOf(envPerm2) Then
            
            Console.WriteLine("'windir' is a subset of 'TEMP'"
 + vbLf)
        Else
            Console.WriteLine("windir" + "
 is not a subset of " + "TEMP" + vbLf)
        End If
        envPerm1.SetPathList(EnvironmentPermissionAccess.Read, "TEMP")
        
        If envPerm1.IsSubsetOf(envPerm2) Then
            
            Console.WriteLine("Read access is a subset of AllAccess"
 + vbLf)
        Else
            Console.WriteLine("Read access is not a subset of
 AllAccess" + vbLf)
        End If
        
        Return returnValue
    
    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 returnValue As Boolean
 = True
        Dim envIdPerm3 As IPermission
        Dim envPerm1 As New
 EnvironmentPermission(EnvironmentPermissionAccess.Read, "windir")
        Dim envPerm2 As New
 EnvironmentPermission(EnvironmentPermissionAccess.Read, "TEMP")
        envIdPerm3 = CType(envPerm1.Union(envPerm2), EnvironmentPermission)
        envIdPerm3 = envPerm1.Union(envPerm2)
        Console.WriteLine("The union of 'windir'
 and 'TEMP'" + " = " + _
        CType(envIdPerm3, EnvironmentPermission).GetPathList(EnvironmentPermissionAccess.Read).ToString())
        
        Return returnValue
    
    End Function 'UnionDemo
     
    ' Intersect creates and returns a new permission that is the intersection
 of
    ' the current permission and the permission specified.
    Private Function IntersectDemo() As
 Boolean 
        
        Dim envIdPerm3 As IPermission
        Dim returnValue As Boolean
 = True
        Dim envPerm1 As New
 EnvironmentPermission(EnvironmentPermissionAccess.Read, "windir")
        Dim envPerm2 As New
 EnvironmentPermission(EnvironmentPermissionAccess.Read, "TEMP")
        Try
            envIdPerm3 = CType(envPerm1.Intersect(envPerm2), EnvironmentPermission)
            If Not (envIdPerm3 Is
 Nothing) AndAlso Not (CType(envIdPerm3,
 _
            EnvironmentPermission).GetPathList(EnvironmentPermissionAccess.Read)
 Is Nothing) Then
                Console.WriteLine("The intersection of "
 + "windir" + " and "
 + "TEMP" + _
                " = " + CType(envIdPerm3, EnvironmentPermission).GetPathList(EnvironmentPermissionAccess.Read).ToString())
            Else
                Console.WriteLine("The intersection of "
 + "windir" + " and "
 + "TEMP" + " is null.")
            End If
        Catch e As Exception
            Console.WriteLine("An exception was thrown for intersection
 : " + e.Message)
            returnValue = False
        End Try
        
        Return returnValue
    
    End Function 'IntersectDemo
     
    'Copy creates and returns an identical copy of the current permission.
    Private Function CopyDemo() As
 Boolean 
        Dim returnValue As Boolean
 = True
        Dim envPerm1 As New
 EnvironmentPermission(EnvironmentPermissionAccess.Read, "windir")
        Try
            Dim envPerm2 As EnvironmentPermission
 = CType(envPerm1.Copy(), EnvironmentPermission)
            If Not (envPerm2 Is
 Nothing) Then
                Console.WriteLine("Result of copy = "
 + envPerm2.ToString() + vbLf)
            Else
                Console.WriteLine("Result of copy is null. "
 + vbLf)
            End If
        Catch e As Exception
            Console.WriteLine(e)
        End Try
        
        Return returnValue
    
    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 returnValue As Boolean
 = True
        Dim envPerm1 As New
 EnvironmentPermission(EnvironmentPermissionAccess.Read, "windir")
        Dim envPerm2 As New
 EnvironmentPermission(PermissionState.None)
        envPerm2.FromXml(envPerm1.ToXml())
        Console.WriteLine("Result of ToFromXml = "
 + envPerm2.ToString() + vbLf)
        
        Return returnValue
    
    End Function 'ToFromXmlDemo
     
    ' AddPathList adds access for the specified environment variables
 to the existing state of the permission.
    ' SetPathList Sets the specified access to the specified environment
 variables to the existing state
    ' of the permission.
    ' GetPathList gets all environment variables with the specified
 EnvironmentPermissionAccess.
    Private Function SetGetPathListDemo() As
 Boolean 
        Try
            Console.WriteLine("********************************************************"
 + vbLf)
            Console.WriteLine("Creating an EnvironmentPermission with
 AllAccess rights for 'TMP'")
            Dim envPerm1 As New
 EnvironmentPermission(EnvironmentPermissionAccess.AllAccess, "TMP")
            Console.WriteLine("Adding 'TEMP' to the write access
 list, and 'windir' to the read access list.")
            envPerm1.AddPathList(EnvironmentPermissionAccess.Write, "TEMP")
            envPerm1.AddPathList(EnvironmentPermissionAccess.Read, "windir")
            Console.WriteLine("Read access list before SetPathList
 = " + envPerm1.GetPathList(EnvironmentPermissionAccess.Read))
            Console.WriteLine("Setting read access to 'TMP'")
            envPerm1.SetPathList(EnvironmentPermissionAccess.Read, "TMP")
            Console.WriteLine("Read access list after SetPathList
 = " + envPerm1.GetPathList(EnvironmentPermissionAccess.Read))
            Console.WriteLine("Write access list = "
 + envPerm1.GetPathList(EnvironmentPermissionAccess.Write))
            Console.WriteLine("Write access environment variables
 = " + envPerm1.GetPathList(EnvironmentPermissionAccess.AllAccess))
        Catch e As ArgumentException
            ' EnvironmentPermissionAccess.AllAccess cannot be used as
 a parameter for GetPathList.
            Console.WriteLine("An ArgumentException occurred as
 a result of using AllAccess. " + _
            " This property cannot be used as a parameter in GetPathList,
 because it represents " + _
            "more than one type of environment variable : "
 + vbLf + e.Message)
        End Try
        
        Return True
    
    End Function 'SetGetPathListDemo
    
    ' Invoke all demos.
    Public Function RunDemo() As
 Boolean 
        
        Dim ret As Boolean
 = True
        Dim retTmp As Boolean
        ' Call IsSubsetOf demo.
        retTmp = IsSubsetOfDemo()
        If retTmp Then

            Console.Out.WriteLine("IsSubset demo completed successfully.")
        Else
            Console.Out.WriteLine("IsSubset demo failed.")
        End If
        ret = retTmp AndAlso ret

      
        ' Call Union demo.
        retTmp = UnionDemo()
        If retTmp Then

            Console.Out.WriteLine("Union demo completed successfully.")
        Else
            Console.Out.WriteLine("Union demo failed.")
        End If
        ret = retTmp AndAlso ret

      
        ' Call Intersect demo.
        retTmp = IntersectDemo()
        If retTmp Then

            Console.Out.WriteLine("Intersect demo completed successfully.")
        Else
            Console.Out.WriteLine("Intersect demo failed.")
        End If
        ret = retTmp AndAlso ret

      

      
        ' Call Copy demo.
        retTmp = CopyDemo()
        If retTmp Then

            Console.Out.WriteLine("Copy demo completed successfully.")
        Else
            Console.Out.WriteLine("Copy demo failed.")
        End If
        ret = retTmp AndAlso ret

      
        ' Call ToFromXml demo.
        retTmp = ToFromXmlDemo()
        If retTmp Then

            Console.Out.WriteLine("ToFromXml demo completed successfully.")
        Else
            Console.Out.WriteLine("ToFromXml demo failed.")
        End If
        ret = retTmp AndAlso ret

      
        ' Call SetGetPathList demo.
        retTmp = SetGetPathListDemo()
        If retTmp Then

            Console.Out.WriteLine("SetGetPathList demo completed
 successfully.")
        Else
            Console.Out.WriteLine("SetGetPathList demo failed.")
        End If
        ret = retTmp AndAlso ret
        
        Return ret
    
    End Function 'RunDemo
     
    ' Test harness.
    Public Shared Sub Main(ByVal
 args() As String) 
        Try
            Dim democase As New
 EnvironmentPermissionDemo()
            Dim ret As Boolean
 = democase.RunDemo()
            If ret Then
                Console.Out.WriteLine("EnvironmentPermission 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("EnvironmentPermission 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("EnvironmentPermission 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 'EnvironmentPermissionDemo

C#

using System;
using System.Security;
using System.Security.Permissions;
using System.Collections;

[assembly: CLSCompliant(true)]

public class EnvironmentPermissionDemo
{
    // IsSubsetOf determines whether the current permission is a subset
 of the specified permission.
    private bool IsSubsetOfDemo()
    {
        bool returnValue = true;
        EnvironmentPermission envPerm1 = new EnvironmentPermission(EnvironmentPermissionAccess.Read,
 "windir");
        EnvironmentPermission envPerm2 = new EnvironmentPermission(EnvironmentPermissionAccess.AllAccess,
 "TEMP");
        if (envPerm1.IsSubsetOf(envPerm2))
        {

            Console.WriteLine("'windir' is a subset of 'TEMP'\n");
        }
        else
        {
            Console.WriteLine("windir" + " is not a subset of "
                + "TEMP" + "\n");
        }
        envPerm1.SetPathList(EnvironmentPermissionAccess.Read, "TEMP");

        if (envPerm1.IsSubsetOf(envPerm2))
        {

            Console.WriteLine("Read access is a subset of AllAccess\n");
        }
        else
        {
            Console.WriteLine("Read access is not a subset of AllAccess\n");
        }

        return returnValue;
    }
    // Union creates a new permission that is the union of the current
 permission and the specified permission.
    private bool UnionDemo()
    {
        bool returnValue = true;
        IPermission envIdPerm3;
        EnvironmentPermission envPerm1 = new EnvironmentPermission(EnvironmentPermissionAccess.Read,
 "windir");
        EnvironmentPermission envPerm2 = new EnvironmentPermission(EnvironmentPermissionAccess.Read,
 "TEMP");
        envIdPerm3 = (EnvironmentPermission)envPerm1.Union(envPerm2);
        envIdPerm3 = envPerm1.Union(envPerm2);
        Console.WriteLine("The union of 'windir' and 'TEMP'" +
            " = " + ((EnvironmentPermission)envIdPerm3).GetPathList(EnvironmentPermissionAccess.Read).ToString());

        return returnValue;

    }
    // Intersect creates and returns a new permission that is the intersection
 of
    // the current permission and the permission specified.
    private bool IntersectDemo()
    {

        IPermission envIdPerm3;
        bool returnValue = true;
        EnvironmentPermission envPerm1 = new EnvironmentPermission(EnvironmentPermissionAccess.Read,
 "windir");
        EnvironmentPermission envPerm2 = new EnvironmentPermission(EnvironmentPermissionAccess.Read,
 "TEMP");
        try
        {
            envIdPerm3 = (EnvironmentPermission)envPerm1.Intersect(envPerm2);
            if (envIdPerm3 != null &&
 ((EnvironmentPermission)envIdPerm3).GetPathList(EnvironmentPermissionAccess.Read)
 != null)
            {
                Console.WriteLine("The intersection of " + "windir"
 + " and " + "TEMP" +                    " = " + ((EnvironmentPermission)envIdPerm3).GetPathList(EnvironmentPermissionAccess.Read).ToString());
            }
            else
            {
                Console.WriteLine("The intersection of " + "windir"
 + " and "
                    + "TEMP" + " is null.");
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("An exception was thrown for
 intersection : " + e);
            returnValue = false;
        }
    
        return returnValue;

    }
    //Copy creates and returns an identical copy of the current permission.
    private bool CopyDemo()
    {
        bool returnValue = true;
        EnvironmentPermission envPerm1 = new EnvironmentPermission(EnvironmentPermissionAccess.Read,
 "windir");
        try
        {
            EnvironmentPermission envPerm2 = (EnvironmentPermission)envPerm1.Copy();
            if (envPerm2 != null)
            {
                Console.WriteLine("Result of copy = " + envPerm2.ToString()
 + "\n");
            }
            else
            {
                Console.WriteLine("Result of copy is null.
 \n");
            }
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
        }

        return returnValue;
    }
    // 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 bool ToFromXmlDemo()
    {
        bool returnValue = true;
        EnvironmentPermission envPerm1 = new EnvironmentPermission(EnvironmentPermissionAccess.Read,
 "windir");
        EnvironmentPermission envPerm2 = new EnvironmentPermission(PermissionState.None);
        envPerm2.FromXml(envPerm1.ToXml());
        Console.WriteLine("Result of ToFromXml = " + envPerm2.ToString()
 + "\n");

        return returnValue;

    }
    // AddPathList adds access for the specified environment variables
 to the existing state of the permission.
    // SetPathList Sets the specified access to the specified environment
 variables to the existing state
    // of the permission.
    // GetPathList gets all environment variables with the specified
 EnvironmentPermissionAccess.
    private bool SetGetPathListDemo()
    {
        try
        {
            Console.WriteLine("********************************************************\n");
            Console.WriteLine("Creating an EnvironmentPermission with AllAccess
 rights for 'TMP'");
            EnvironmentPermission envPerm1 = new EnvironmentPermission(EnvironmentPermissionAccess.AllAccess,
 "TMP");
            Console.WriteLine("Adding 'TEMP' to the write access list, and 'windir'
 to the read access list.");
            envPerm1.AddPathList(EnvironmentPermissionAccess.Write, "TEMP");
            envPerm1.AddPathList(EnvironmentPermissionAccess.Read, "windir");
            Console.WriteLine("Read access list before SetPathList = "
                + envPerm1.GetPathList(EnvironmentPermissionAccess.Read));
            Console.WriteLine("Setting read access to 'TMP'");
            envPerm1.SetPathList(EnvironmentPermissionAccess.Read, "TMP");
            Console.WriteLine("Read access list after SetPathList = "
                + envPerm1.GetPathList(EnvironmentPermissionAccess.Read));
            Console.WriteLine("Write access list = " + envPerm1.GetPathList(EnvironmentPermissionAccess.Write));
            Console.WriteLine("Write access environment variables = "
                + envPerm1.GetPathList(EnvironmentPermissionAccess.AllAccess));
        }
        catch (ArgumentException e)
        {
            // EnvironmentPermissionAccess.AllAccess cannot be used
 as a parameter for GetPathList.
            Console.WriteLine("An ArgumentException occurred as a result of
 using AllAccess. "
                + " This property cannot be used as a parameter in
 GetPathList, because it represents "
                + "more than one type of environment variable : \n" + e);
        }

        return true;
    }
    // Invoke all demos.
    public bool RunDemo()
    {

        bool ret = true;
        bool retTmp;
        // Call IsSubsetOf demo.
        if (retTmp = IsSubsetOfDemo()) Console.Out.WriteLine("IsSubset
 demo completed successfully.");
        else Console.Out.WriteLine("IsSubset demo failed.");
        ret = retTmp && ret;

        // Call Union demo.
        if (retTmp = UnionDemo()) Console.Out.WriteLine("Union
 demo completed successfully.");
        else Console.Out.WriteLine("Union demo failed.");
        ret = retTmp && ret;

        // Call Intersect demo.
        if (retTmp = IntersectDemo()) Console.Out.WriteLine("Intersect
 demo completed successfully.");
        else Console.Out.WriteLine("Intersect demo failed.");
        ret = retTmp && ret;


        // Call Copy demo.
        if (retTmp = CopyDemo()) Console.Out.WriteLine("Copy
 demo completed successfully.");
        else Console.Out.WriteLine("Copy demo failed.");
        ret = retTmp && ret;

        // Call ToFromXml demo.
        if (retTmp = ToFromXmlDemo()) Console.Out.WriteLine("ToFromXml
 demo completed successfully.");
        else Console.Out.WriteLine("ToFromXml demo failed.");
        ret = retTmp && ret;

        // Call SetGetPathList demo.
        if (retTmp = SetGetPathListDemo()) Console.Out.WriteLine("SetGetPathList
 demo completed successfully.");
        else Console.Out.WriteLine("SetGetPathList demo failed.");
        ret = retTmp && ret;

        return (ret);

    }
    // Test harness.
    public static void Main(String[]
 args)
    {
        try
        {
            EnvironmentPermissionDemo democase = new EnvironmentPermissionDemo();
            bool ret = democase.RunDemo();
            if (ret)
            {
                Console.Out.WriteLine("EnvironmentPermission demo completed
 successfully.");
                Console.Out.WriteLine("Press the Enter key to exit.");
                string consoleInput = Console.ReadLine();
                System.Environment.ExitCode = 100;
            }
            else
            {
                Console.Out.WriteLine("EnvironmentPermission demo failed.");
                Console.Out.WriteLine("Press the Enter key to exit.");
                string consoleInput = Console.ReadLine();
                System.Environment.ExitCode = 101;
            }
        }
        catch (Exception e)
        {
            Console.Out.WriteLine("EnvironmentPermission demo failed.");
            Console.WriteLine(e.ToString());
            Console.Out.WriteLine("Press the Enter key to exit.");
            string consoleInput = Console.ReadLine();
            System.Environment.ExitCode = 101;
        }
    }
}

継承階層

System.Object
   System.Security.CodeAccessPermission
    System.Security.Permissions.EnvironmentPermission

スレッド セーフ

この型の public static (Visual Basic では Shared) メンバはすべて、スレッド セーフです。インスタンス メンバの場合は、スレッド セーフであるとは限りません。

プラットフォーム

Windows 98, Windows 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

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0

参照

関連項目
EnvironmentPermission メンバ
System.Security.Permissions 名前空間
EnvironmentPermissionAttribute
EnvironmentPermissionAccess
その他の技術情報
アクセス許可
アクセス許可の要求