Ejemplo StopProcessSample01
En este ejemplo se muestra cómo escribir un cmdlet que solicita comentarios del usuario antes de intentar detener un proceso y cómo implementar un parámetro PassThru que indica que el usuario quiere que el cmdlet devuelva un objeto. Este cmdlet es similar al cmdlet Stop-Process proporcionado por Windows PowerShell 2.0.
Cómo compilar el ejemplo mediante Visual Studio
Con el SDK de Windows PowerShell 2.0 instalado, vaya a la carpeta StopProcessSample01. La ubicación predeterminada es
C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0\Samples\sysmgmt\WindowsPowerShell\csharp\StopProcessSample01.Haga doble clic en el icono del archivo de solución (.sln). Se abre el proyecto de ejemplo en Microsoft Visual Studio.
En el menú compilación de, seleccione Compilar solución para compilar la biblioteca para el ejemplo en las carpetas de
\bino\bin\debugpredeterminadas.
Cómo ejecutar el ejemplo
Cree la siguiente carpeta de módulo:
[user]\Documents\WindowsPowerShell\Modules\StopProcessSample01Copie el ensamblado de ejemplo en la carpeta del módulo.
Inicie Windows PowerShell.
Ejecute el siguiente comando para cargar el ensamblado en Windows PowerShell:
Import-Module stopprossessample01Ejecute el siguiente comando para ejecutar el cmdlet :
Stop-Proc
Requisitos
Este ejemplo requiere Windows PowerShell 2.0.
Demostraciones
En este ejemplo se muestra lo siguiente.
Declaración de una clase de cmdlet mediante el atributo Cmdlet.
Declaración de parámetros de cmdlet mediante el atributo Parameter.
Llamar al método ShouldProcess para solicitar confirmación.
Implementación de un parámetro
PassThruque indica si el usuario quiere que el cmdlet devuelva un objeto. De forma predeterminada, este cmdlet no devuelve un objeto a la canalización.
Ejemplo
En este ejemplo se muestra cómo implementar un parámetro PassThru que indica que el usuario quiere que el cmdlet devuelva un objeto y cómo solicitar comentarios del usuario mediante llamadas a los métodos ShouldProcess y ShouldContinue.
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)
{
// For every process name passed to the cmdlet, get the associated
// processes.
// Write a non-terminating error for failure to retrieve
// a process.
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.ReadError, process));
continue;
}
// Confirm the operation with the user first.
// This is always false if the WhatIf parameter is set.
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 could possibly stop the computer.
bool criticalProcess =
criticalProcessNames.Contains(processName.ToLower(CultureInfo.CurrentCulture));
if (criticalProcess &&!force)
{
string 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...
// 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
// If the PassThru parameter is
// specified, return the terminated process.
if (passThru)
{
WriteObject(process);
}
} // 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
}
