从 C# 以编程方式调用 CmdLet 时，如何捕获 Powershell CmdLet 的详细输出

How to capture a Powershell CmdLet's verbose output when the CmdLet is programmatically Invoked from C#

提问by namenlos

BACKGROUND

背景

• I am using Powershell 2.0 on Windows 7.
• I am writing a cmdlet in a Powershell module ("module" is new to Powershell 2.0).
• To test the cmdlet I am writing Unit tests in Visual Studio 2008 that programmatically invoke the cmdlet.

• 我在 Windows 7 上使用 Powershell 2.0。
• 我正在 Powershell 模块中编写一个 cmdlet（“模块”是 Powershell 2.0 的新功能）。
• 为了测试 cmdlet，我正在 Visual Studio 2008 中编写单元测试，以编程方式调用 cmdlet。

REFERENCE

参考

• This Article on MSDNcalled "How to Invoke a Cmdlet from Within a Cmdlet" shows how to call a cmdlet from C#.

• MSDN 上的这篇名为“如何从 Cmdlet 中调用 Cmdlet”的文章展示了如何从 C# 调用 cmdlet。

THE SOURCE CODE

源代码

• This is a distilled version of my actual code — I've made it as small as possible so that you can see the problem I am having clearly:

  using System;
  using System.Management.Automation;   
  
  namespace DemoCmdLet1
  {
      class Program
      {
          static void Main(string[] args)
          {
              var cmd = new GetColorsCommand();
  
                  foreach ( var i in cmd.Invoke<string>())
                  {
                     Console.WriteLine("- " + i );   
                  } 
             } 
         } 
  
      [Cmdlet("Get", "Colors")]
      public class GetColorsCommand : Cmdlet
      {
          protected override void ProcessRecord()
          {
              this.WriteObject("Hello");
              this.WriteVerbose("World");
          }
  
      }
  }
  

• 这是我实际代码的提炼版本——我已经把它做得尽可能小，这样你就可以清楚地看到我遇到的问题：

  using System;
  using System.Management.Automation;   
  
  namespace DemoCmdLet1
  {
      class Program
      {
          static void Main(string[] args)
          {
              var cmd = new GetColorsCommand();
  
                  foreach ( var i in cmd.Invoke<string>())
                  {
                     Console.WriteLine("- " + i );   
                  } 
             } 
         } 
  
      [Cmdlet("Get", "Colors")]
      public class GetColorsCommand : Cmdlet
      {
          protected override void ProcessRecord()
          {
              this.WriteObject("Hello");
              this.WriteVerbose("World");
          }
  
      }
  }
  

COMMENTS

注释

• I understand how to enable and capture verbose output from the Powershell command line; that's not the problem.
• In this case I am programmatically invoking the cmdlet from C#.
• Nothing I've found addresses my specific scenario. Some articles suggest I should implement my own PSHost, but seems expensive and also it seems like a have to call the cmdlet as text, which I would like to avoid because that is not as strongly typed.

• 我了解如何从 Powershell 命令行启用和捕获详细输出；那不是问题。
• 在这种情况下，我以编程方式从 C# 调用 cmdlet。
• 我发现的任何内容都不能解决我的具体情况。一些文章建议我应该实现我自己的 PSHost，但看起来很昂贵，而且似乎必须将 cmdlet 作为文本调用，我想避免这种情况，因为它不是强类型的。

UPDATE ON 2009-07-20

2009-07-20 更新

Here is is the source code based on the answer below.

这是基于以下答案的源代码。

Some things are still not clear to me: * How to call the "Get-Colors" cmdlet (ideally without having to pass it as a string to the ps objet) * How to get the verbose output as it is generatedinstead of getting an collection of them at the end.

有些事情我仍然不清楚： * 如何调用“Get-Colors”cmdlet（理想情况下不必将其作为字符串传递给 ps objet） * 如何在生成时获取详细输出而不是获取最后收集它们。

    using System;
    using System.Management.Automation;   

    namespace DemoCmdLet1
    {
        class Program
        {
            static void Main(string[] args)
            {
                var ps = System.Management.Automation.PowerShell.Create();

                ps.Commands.AddScript("$verbosepreference='continue'; write-verbose 42");

                foreach ( var i in ps.Invoke<string>())
                {
                   Console.WriteLine("normal output: {0}" , i );   
                }
                foreach (var i in ps.Streams.Verbose)
                {
                    Console.WriteLine("verbose output: {0}" , i);
                }

            }
        }

        [Cmdlet("Get", "Colors")]
        public class GetColorsCommand : Cmdlet
        {
            protected override void ProcessRecord()
            {
                this.WriteObject("Red");
                this.WriteVerbose("r");
                this.WriteObject("Green");
                this.WriteVerbose("g");
                this.WriteObject("Blue");
                this.WriteVerbose("b");

            }

        }
    }

The code above generates this output:

上面的代码生成此输出：

d:\DemoCmdLet1\DemoCmdLet1>bin\Debug\DemoCmdLet1.exe
verbose output: 42

UPDATE ON 2010-01-16

2010-01-16 更新

by using the Powershell class (found in System.Management.Automation but only in the version of the assembly that comes with the powershell 2.0 SDK, not what comes out-of-the-box on Windows 7) I can programmatically call the cmdlet and get the verbose output. The remaining part is to actually add a custom cmdlet to that powershell instance - because that was my original goal - to unit test my cmdlets not those that come with powershell.

通过使用 Powershell 类（在 System.Management.Automation 中找到，但仅在 powershell 2.0 SDK 附带的程序集版本中，而不是在 Windows 7 上开箱即用的）我可以以编程方式调用 cmdlet 和获取详细输出。剩下的部分是实际向该 powershell 实例添加自定义 cmdlet - 因为这是我的最初目标 - 对我的 cmdlet 进行单元测试，而不是那些与 powershell 一起使用的 cmdlet。

class Program
{
    static void Main(string[] args)
    {
        var ps = System.Management.Automation.PowerShell.Create();
        ps.AddCommand("Get-Process");
        ps.AddParameter("Verbose");
        ps.Streams.Verbose.DataAdded += Verbose_DataAdded;
        foreach (PSObject result in ps.Invoke())
        {
            Console.WriteLine(
                    "output: {0,-24}{1}",
                    result.Members["ProcessName"].Value,
                    result.Members["Id"].Value);
        } 
        Console.ReadKey();
    }

    static void Verbose_DataAdded(object sender, DataAddedEventArgs e)
    {
        Console.WriteLine( "verbose output: {0}", e.Index);
    }
}


[Cmdlet("Get", "Colors")]
public class GetColorsCommand : Cmdlet
{
    protected override void ProcessRecord()
    {
        this.WriteObject("Hello");
        this.WriteVerbose("World");
    }
}

回答by x0n

• Verbose output is not actually output unless $VerbosePreferenceis set at least to "Continue."
• Use the PowerShell type to run your cmdlet, and read VerboseRecordinstances from the Streams.Verbosepropery

• 除非$VerbosePreference至少设置为“继续”，否则详细输出实际上并不是输出。
• 使用 PowerShell 类型运行您的cmdlet，并VerboseRecord从Streams.Verbose属性中读取实例

Example in powershell script:

PowerShell 脚本中的示例：

ps> $ps = [powershell]::create()
ps> $ps.Commands.AddScript("`$verbosepreference='continue'; write-verbose 42")
ps> $ps.invoke()
ps> $ps.streams.verbose
Message   InvocationInfo                          PipelineIterationInfo
-------   --------------                          ---------------------
42        System.Management.Automation.Invocat... {0, 0}

This should be easy to translate into C#.

这应该很容易转换为 C#。

回答by Varun

1.        string scriptFile = "Test.ps1";
2.        using (PowerShell ps = PowerShell.Create())
3.        {
4.          const string getverbose = "$verbosepreference='continue'"; 
5.          ps.AddScript(string.Format(getverbose));
6.          ps.Invoke();
7.          ps.Commands.Clear();
8.          ps.AddScript(@".\" + scriptFile);
9.          ps.Invoke();
10.         foreach (var v in ps.Streams.Verbose)
11.         {
12.               Console.WriteLine(v.Message);
13.         }
14.       }

Important lines are line 5 and 6. This basically set the $verbosepreference for the session and for upcoming new commands and scripts.

重要的行是第 5 行和第 6 行。这基本上为会话和即将到来的新命令和脚本设置了 $verbosepreference。