EnvironmentPermission.SetPathList 方法

将对指定环境变量的指定访问权限设置为该权限的现有状态。

**命名空间:**System.Security.Permissions
**程序集:**mscorlib（在 mscorlib.dll 中）

语法

声明
Public Sub SetPathList ( _
    flag As EnvironmentPermissionAccess, _
    pathList As String _
)
用法
Dim instance As EnvironmentPermission
Dim flag As EnvironmentPermissionAccess
Dim pathList As String

instance.SetPathList(flag, pathList)

public void SetPathList (
    EnvironmentPermissionAccess flag,
    string pathList
)

public:
void SetPathList (
    EnvironmentPermissionAccess flag, 
    String^ pathList
)

public void SetPathList (
    EnvironmentPermissionAccess flag, 
    String pathList
)

public function SetPathList (
    flag : EnvironmentPermissionAccess, 
    pathList : String
)

参数

• flag
  EnvironmentPermissionAccess 值之一。

• pathList
  环境变量的列表（用分号分隔）。

异常

异常类型	条件
ArgumentNullException	pathList 参数为 空引用（在 Visual Basic 中为 Nothing）。
ArgumentException	flag 参数不是有效的 EnvironmentPermissionAccess 值。

备注

当前权限的前一状态被改写。

示例

下面的代码示例演示 SetPathList 方法的用法。此代码示例摘自一个为 EnvironmentPermission 类提供的更大的示例。

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

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;
}

平台

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

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

EnvironmentPermission 类
EnvironmentPermission 成员
System.Security.Permissions 命名空间