出于性能或安全原因,你可能希望限制主机应用程序可用的 Windows PowerShell 命令。 为此,请通过调用 System.Management.Automation.Runspaces.InitialSessionState 创建空 System.Management.Automation.Runspaces.InitialSessionState.Create* 方法,然后仅添加所需的命令。
使用仅加载指定命令的 Runspace 可显著提高性能。
使用 System.Management.Automation.Runspaces.SessionStateCmdletEntry 类的方法定义初始会话状态的 cmdlet。
还可以将命令设为专用。 专用命令可由主机应用程序使用,但不能由应用程序的用户使用。
将命令添加到空运行空间
以下示例演示如何创建空 InitialSessionState 并向其添加命令。
namespace Microsoft.Samples.PowerShell.Runspaces
{
using System;
using System.Collections.ObjectModel;
using System.Management.Automation;
using System.Management.Automation.Runspaces;
using Microsoft.PowerShell.Commands;
using PowerShell = System.Management.Automation.PowerShell;
/// <summary>
/// This class contains the Main entry point for the application.
/// </summary>
internal class Runspace10b
{
/// <summary>
/// This sample shows how to create an empty initial session state,
/// how to add commands to the session state, and then how to create a
/// runspace that has only those two commands. A PowerShell object
/// is used to run the Get-Command cmdlet to show that only two commands
/// are available.
/// </summary>
/// <param name="args">Parameter not used.</param>
private static void Main(string[] args)
{
// Create an empty InitialSessionState and then add two commands.
InitialSessionState iss = InitialSessionState.Create();
// Add the Get-Process and Get-Command cmdlets to the session state.
SessionStateCmdletEntry ssce1 = new SessionStateCmdletEntry(
"Get-Process",
typeof(GetProcessCommand),
null);
iss.Commands.Add(ssce1);
SessionStateCmdletEntry ssce2 = new SessionStateCmdletEntry(
"Get-Command",
typeof(GetCommandCommand),
null);
iss.Commands.Add(ssce2);
// Create a runspace.
using (Runspace myRunSpace = RunspaceFactory.CreateRunspace(iss))
{
myRunSpace.Open();
using (PowerShell powershell = PowerShell.Create())
{
powershell.Runspace = myRunSpace;
// Create a pipeline with the Get-Command command.
powershell.AddCommand("Get-Command");
Collection<PSObject> results = powershell.Invoke();
Console.WriteLine("Verb Noun");
Console.WriteLine("----------------------------");
// Display each result object.
foreach (PSObject result in results)
{
Console.WriteLine(
"{0,-20} {1}",
result.Members["verb"].Value,
result.Members["Noun"].Value);
}
}
// Close the runspace and release any resources.
myRunSpace.Close();
}
System.Console.WriteLine("Hit any key to exit...");
System.Console.ReadKey();
}
}
}
将命令制作为专用命令
还可以通过将命令设置为 System.Management.Automation.CommandInfo.Visibility 属性设置为 System.Management.Automation.SessionStateEntryVisibilityPrivate,从而将命令设为私有。 主机应用程序和其他命令可以调用该命令,但应用程序的用户不能。 在以下示例中,Get-ChildItem 命令是私有的。
defaultSessionState = InitialSessionState.CreateDefault();
commandIndex = GetIndexOfEntry(defaultSessionState.Commands, "Get-ChildItem");
defaultSessionState.Commands[commandIndex].Visibility = SessionStateEntryVisibility.Private;
this.runspace = RunspaceFactory.CreateRunspace(defaultSessionState);
this.runspace.Open();