Amostra StopProcessSample02
Este exemplo mostra como escrever um cmdlet que grava mensagens de depuração (WriteDebug), detalhadas (WriteVerbose) e aviso (WriteWarning) ao parar processos no computador local. Esse cmdlet é semelhante ao cmdlet Stop-Process fornecido pelo Windows PowerShell 2.0.
Como criar o exemplo usando o Visual Studio
Abra o Windows Internet Explorer e navegue até o diretório StopProcessSample02 no diretório Exemplos.
Com o SDK do Windows PowerShell 2.0 instalado, navegue até a pasta StopProcessSample02. A localização predefinida é
C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0\Samples\sysmgmt\WindowsPowerShell\csharp\StopProcessSample02.Clique duas vezes no ícone do arquivo de solução (.sln). Isso abre o projeto de exemplo no Microsoft Visual Studio.
No menu Criar, selecione Criar solução para criar a biblioteca para o exemplo nas pastas
\binou\bin\debugpadrão.
Como executar o exemplo
Crie a seguinte pasta de módulo:
[user]\Documents\WindowsPowerShell\Modules\StopProcessSample02Copie o assembly de exemplo para a pasta do módulo.
Inicie o Windows PowerShell.
Execute o seguinte comando para carregar o assembly no Windows PowerShell:
Import-Module stopprossessample02Execute o seguinte comando para executar o cmdlet:
Stop-Proc
Requisitos
Este exemplo requer o Windows PowerShell 2.0.
Demonstra
Este exemplo demonstra o seguinte.
Declarando uma classe de cmdlet usando o atributo Cmdlet.
Declarando parâmetros de cmdlet usando o atributo Parameter.
Gravando mensagens detalhadas. Para obter mais informações sobre o método usado para gravar mensagens detalhadas, consulte System.Management.Automation.Cmdlet.WriteVerbose.
Gravando mensagens de erro. Para obter mais informações sobre o método usado para gravar mensagens de erro, consulte System.Management.Automation.Cmdlet.WriteError.
Escrevendo mensagens de aviso. Para obter mais informações sobre o método usado para gravar mensagens de aviso, consulte System.Management.Automation.Cmdlet.WriteWarning.
Exemplo
Este exemplo mostra como gravar mensagens de depuração, detalhadas e de aviso usando os métodos WriteDebug, WriteVerbosee WriteWarning.
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
}
