StopProcessSample02 示例

此示例演示如何编写一个 cmdlet，在停止本地计算机上的进程时写入调试 (WriteDebug)、详细 (WriteVerbose) 和警告 (WriteWarning) 消息。此 cmdlet 类似于 Windows PowerShell 2.0 提供的 Stop-Process cmdlet。

如何使用 Visual Studio 构建示例

1. 打开 Windows Internet Explorer 并导航到 Samples 目录下的 StopProcessSample02 目录。

   安装 Windows PowerShell 2.0 SDK 后，导航到 StopProcessSample02 文件夹。默认位置为 C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0\Samples\sysmgmt\WindowsPowerShell\csharp\StopProcessSample02。

2. 双击解决方案 (.sln) 文件的图标。这将在 Microsoft Visual Studio 中打开示例项目。

3. 在构建菜单中，选择构建解决方案在默认的\bin或\bin\debug 文件夹。

如何运行示例

1. 创建以下模块文件夹：

   [user]\Documents\WindowsPowerShell\Modules\StopProcessSample02

2. 将示例程序集复制到模块文件夹。

3. 启动 Windows PowerShell。

4. 运行以下命令将程序集加载到 Windows PowerShell 中：

   Import-Module stopprossessample02

5. 运行以下命令来运行 cmdlet：

   stop-proc

要求

此示例需要 Windows PowerShell 2.0。

示范

该示例演示了以下内容。

• 使用 Cmdlet 属性声明 cmdlet 类。

• 使用 Parameter 属性声明 cmdlet 参数。

• 编写详细消息。有关用于写入详细消息的方法的详细信息，请参阅 System.Management.Automation.Cmdlet.WriteVerbose。

• 写入错误消息。有关用于写入错误消息的方法的详细信息，请参阅 System.Management.Automation.Cmdlet.WriteError。

• 编写警告消息。有关用于写入警告消息的方法的详细信息，请参阅 System.Management.Automation.Cmdlet.WriteWarning。

例子

此示例演示如何使用 WriteDebug、WriteVerbose 和 WriteWarning 方法编写调试消息、详细消息和警告消息。

using System;
using System.Diagnostics;
using System.Collections;
using Win32Exception = System.ComponentModel.Win32Exception;
using System.Management.Automation;             //Windows PowerShell namespace
using System.Globalization;

namespace Microsoft.Samples.PowerShell.Commands
{
   #region StopProcCommand

    /// <summary>
   /// This class implements the stop-proc cmdlet.
   /// </summary>
   [Cmdlet(VerbsLifecycle.Stop, "Proc",
       SupportsShouldProcess = true)]
   public class StopProcCommand : Cmdlet
   {
       #region Parameters

      /// <summary>
      /// This parameter provides the list of process names on
      /// which the Stop-Proc cmdlet will work.
      /// </summary>
       [Parameter(
          Position = 0,
          Mandatory = true,
          ValueFromPipeline = true,
          ValueFromPipelineByPropertyName = true
       )]
       public string[] Name
       {
          get { return processNames; }
          set { processNames = value; }
       }
       private string[] processNames;

       /// <summary>
       /// This parameter overrides the ShouldContinue call to force
       /// the cmdlet to stop its operation. This parameter should always
       /// be used with caution.
       /// </summary>
       [Parameter]
       public SwitchParameter Force
       {
           get { return force; }
           set { force = value; }
       }
       private bool force;

       /// <summary>
       /// This parameter indicates that the cmdlet should return
       /// an object to the pipeline after the processing has been
       /// completed.
       /// </summary>
       [Parameter]
       public SwitchParameter PassThru
       {
           get { return passThru; }
           set { passThru = value; }
       }
       private bool passThru;

       #endregion Parameters

       #region Cmdlet Overrides

       /// <summary>
       /// The ProcessRecord method does the following for each of the
       /// requested process names:
       /// 1) Check that the process is not a critical process.
       /// 2) Attempt to stop that process.
       /// If no process is requested then nothing occurs.
       /// </summary>
       protected override void ProcessRecord()
       {
           foreach (string name in processNames)
           {
               string message = null;

               // For every process name passed to the cmdlet, get the associated
               // processes.
               // Write a non-terminating error for failure to retrieve
               // a process.

               // Write a user-friendly verbose message to the pipeline. These
               // messages are intended to give the user detailed information
               // on the operations performed by the cmdlet. These messages will
               // appear with the -Verbose option.
               message = String.Format(CultureInfo.CurrentCulture,
                              "Attempting to stop process \"{0}\".", name);
               WriteVerbose(message);

               Process[] processes;

               try
               {
                   processes = Process.GetProcessesByName(name);
               }
               catch (InvalidOperationException ioe)
               {
                   WriteError(new ErrorRecord(ioe,
                                     "UnableToAccessProcessByName",
                                         ErrorCategory.InvalidOperation,
                                             name));
                   continue;
               }

               // Try to stop the processes that have been retrieved.
               foreach (Process process in processes)
               {
                   string processName;

                   try
                   {
                       processName = process.ProcessName;
                   }
                   catch (Win32Exception e)
                   {
                       WriteError(new ErrorRecord(e, "ProcessNameNotFound",
                                         ErrorCategory.ObjectNotFound, process));
                       continue;
                   }

                   // Write a debug message to the host that can be used when
                   // troubleshooting a problem. All debug messages will appear
                   // with the -Debug option.
                   message = String.Format(CultureInfo.CurrentCulture,
                                 "Acquired name for pid {0} : \"{1}\"",
                                        process.Id, processName);
                   WriteDebug(message);

                   // Confirm the operation first.
                   // This is always false if the WhatIf parameter is specified.
                   if (!ShouldProcess(string.Format(CultureInfo.CurrentCulture,
                                        "{0} ({1})",
                                            processName, process.Id)))
                   {
                       continue;
                   }

                   // Make sure that the user really wants to stop a critical
                   // process that can possibly stop the computer.
                   bool criticalProcess = criticalProcessNames.Contains(processName.ToLower(CultureInfo.CurrentCulture));

                   if (criticalProcess && !force)
                   {
                       message = String.Format(CultureInfo.CurrentCulture,
                                    "The process \"{0}\" is a critical process and should not be stopped. Are you sure you wish to stop the process?",
                                        processName);

                       // It is possible that the ProcessRecord method is called
                       // multiple times when objects are received as inputs from
                       // the pipeline. So to retain YesToAll and NoToAll input that
                       // the user may enter across multiple calls to this function,
                       // they are stored as private members of the cmdlet.
                       if (!ShouldContinue(message, "Warning!",
                                    ref yesToAll, ref noToAll))
                       {
                           continue;
                       }
                   } // if (criticalProcess...

                   // Display a warning message if the cmdlet is stopping a
                   // critical process.
                   if (criticalProcess)
                   {
                       message = String.Format(CultureInfo.CurrentCulture,
                                     "Stopping the critical process \"{0}\".",
                                          processName);
                       WriteWarning(message);
                   } // if (criticalProcess...

                   // Stop the named process.
                   try
                   {
                       process.Kill();
                   }
                   catch (Exception e)
                   {
                       if ((e is Win32Exception) || (e is SystemException) ||
                           (e is InvalidOperationException))
                       {
                           // This process could not be stopped so write
                           // a non-terminating error.
                           WriteError(new ErrorRecord(
                                            e,
                                            "CouldNotStopProcess",
                                            ErrorCategory.CloseError,
                                            process)
                                      );
                           continue;
                       } // if ((e is...
                           else throw;
                   } // catch

                   message = String.Format(CultureInfo.CurrentCulture,
                                  "Stopped process \"{0}\", pid {1}.",
                                        processName, process.Id);

                   WriteVerbose(message);

                   // If the PassThru parameter is specified,
                   // return the terminated process object to the pipeline.
                   if (passThru)
                   {
                       message = String.Format(CultureInfo.CurrentCulture,
                                     "Writing process \"{0}\" to pipeline",
                                          processName);
                       WriteDebug(message);
                       WriteObject(process);
                   } // if (passThru...
               } // foreach (Process...
            } // foreach (string...
        } // ProcessRecord

       #endregion Cmdlet Overrides

       #region Private Data

       private bool yesToAll, noToAll;

       /// <summary>
       /// Partial list of critical processes that should not be
       /// stopped.  Lower case is used for case insensitive matching.
       /// </summary>
       private ArrayList criticalProcessNames = new ArrayList(
          new string[] { "system", "winlogon", "spoolsv" }
       );

       #endregion Private Data

   } // StopProcCommand

   #endregion StopProcCommand
}

参见

• 编写 Windows PowerShell Cmdlet