此範例示範如何撰寫 Cmdlet,以在本機電腦上停止進程時寫入偵錯 (WriteDebug)、詳細資訊 (WriteVerbose) 和警告 (WriteWarning) 訊息。 此 Cmdlet 類似於 Windows PowerShell 2.0 所提供的 Stop-Process Cmdlet。
如何使用 Visual Studio 建置範例
開啟 Windows Internet Explorer,然後流覽至 Samples 目錄下的 StopProcessSample02 目錄。
安裝 Windows PowerShell 2.0 SDK 後,流覽至 StopProcessSample02 資料夾。 預設位置為
C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0\Samples\sysmgmt\WindowsPowerShell\csharp\StopProcessSample02。按兩下解決方案 (.sln) 檔案的圖示。 這會在 Visual Studio 中開啟範例專案Microsoft。
在 [建置] 功能表中,選取 [建置方案],以在預設
\bin或\bin\debug資料夾中建置範例的連結庫。
如何執行範例
建立下列模組資料夾:
[user]\Documents\WindowsPowerShell\Modules\StopProcessSample02將範例元件複製到模組資料夾。
啟動 Windows PowerShell。
執行下列命令,將元件載入 Windows PowerShell:
Import-Module stopprossessample02執行下列命令以執行 Cmdlet:
Stop-Proc
需求
此範例需要 Windows PowerShell 2.0。
演示
此範例示範下列專案。
使用 Cmdlet 屬性宣告 Cmdlet 類別。
使用 Parameter 屬性宣告 Cmdlet 參數。
撰寫詳細資訊訊息。 如需用來寫入詳細資訊訊息的方法詳細資訊,請參閱 System.Management.Automation.Cmdlet.WriteVerbose。
撰寫錯誤訊息。 如需用來寫入錯誤訊息的方法詳細資訊,請參閱 System.Management.Automation.Cmdlet.WriteError。
撰寫警告訊息。 如需用來寫入警告訊息的方法詳細資訊,請參閱 System.Management.Automation.Cmdlet.WriteWarning。
範例
此範例示範如何使用 WriteDebug、WriteVerbose和 WriteWarning 方法來撰寫偵錯、詳細資訊和警告訊息。
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
}