StopProcessSample03-Beispiel
In diesem Beispiel wird gezeigt, wie Sie ein Cmdlet schreiben, dessen Parameter Aliase enthalten und deren Parameter Platzhalterzeichen unterstützen. Dieses Cmdlet ähnelt dem von Windows PowerShell Stop-Process 2.0 bereitgestellten Cmdlet.
Erstellen des Beispiels mithilfe Visual Studio.
Wenn das Windows PowerShell 2.0 SDK installiert ist, navigieren Sie zum Ordner StopProcessSample03. Der Standardspeicherort ist C:\Programme (x86)\Microsoft SDKs\Windows\v7.0\Samples\sysmgmt\WindowsPowerShell\csharp\StopProcessSample03.
Doppelklicken Sie auf das Symbol für die Projektmappendatei (SLN). Dadurch wird das Beispielprojekt in Microsoft Visual Studio.
Wählen Sie im Menü Erstellen die Option Projektmappe erstellen aus.
Die Bibliothek für das Beispiel wird in den Standardordnern \bin oder \bin\debug erstellt.
Ausführen des Beispiels
Erstellen Sie den folgenden Modulordner:
[user]/documents/windowspowershell/modules/StopProcessSample03Kopieren Sie die Beispiel-Assembly in den Modulordner.
Starten Sie Windows PowerShell.
Führen Sie den folgenden Befehl aus, um die Assembly in Windows PowerShell:
import-module stopprossessample03Führen Sie den folgenden Befehl aus, um das Cmdlet auszuführen:
stop-proc
Anforderungen
Dieses Beispiel erfordert Windows PowerShell 2.0.
Zeigt
In diesem Beispiel wird Folgendes veranschaulicht:
Deklarieren einer Cmdlet-Klasse mithilfe des Cmdlet-Attributs.
Deklarieren von Cmdlet-Parametern mithilfe des Parameter-Attributs.
Hinzufügen von Aliasen zu Parameterdeklarationen.
Hinzufügen von Platzhalterunterstützung zu Parametern.
Beispiel
In diesem Beispiel wird gezeigt, wie Parameteraliase deklariert und Platzhalter unterstützt werden.
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,
HelpMessage = "The name of one or more processes to stop. Wildcards are permitted."
)]
[Alias("ProcessName")]
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(
ValueFromPipelineByPropertyName = true,
HelpMessage = "If set, the process(es) will be passed to the pipeline after stopped."
)]
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()
{
Process[] processes = null;
try
{
processes = Process.GetProcesses();
}
catch (InvalidOperationException ioe)
{
base.ThrowTerminatingError(new ErrorRecord(ioe,
"UnableToAccessProcessList",
ErrorCategory.InvalidOperation,
null));
}
// For every process name passed to the cmdlet, get the associated
// processes.
// Write a nonterminating error for failure to retrieve
// a process.
foreach (string name in processNames)
{
// 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.
string message = String.Format(CultureInfo.CurrentCulture,
"Attempting to stop process \"{0}\".", name);
WriteVerbose(message);
// Validate the process name against a wildcard pattern.
// If the name does not contain any wildcard patterns, it
// will be treated as an exact match.
WildcardOptions options = WildcardOptions.IgnoreCase |
WildcardOptions.Compiled;
WildcardPattern wildcard = new WildcardPattern(name,options);
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);
// Check to see if this process matches the current process
// name pattern. Skip this process if it does not.
if (!wildcard.IsMatch(processName))
{
continue;
}
// Stop the process.
SafeStopProcess(process);
} // foreach (Process...
} // foreach (string...
} // ProcessRecord
#endregion Cmdlet Overrides
#region Helper Methods
/// <summary>
/// Safely stops a named process. Used as standalone function
/// to declutter the ProcessRecord method.
/// </summary>
/// <param name="process">The process to stop.</param>
private void SafeStopProcess(Process process)
{
string processName = null;
try
{
processName = process.ProcessName;
}
catch (Win32Exception e)
{
WriteError(new ErrorRecord(e, "ProcessNameNotFound",
ErrorCategory.ObjectNotFound, process));
return;
}
string message = null;
// 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)))
{
return;
}
// 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)
{
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 ProcessRecord is called multiple
// when objects are received as inputs from a 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))
{
return;
}
} // if (criticalProcess...
// Display a warning message if stopping a critical
// process.
if (criticalProcess)
{
message = String.Format(CultureInfo.CurrentCulture,
"Stopping the critical process \"{0}\".",
processName);
WriteWarning(message);
} // if (criticalProcess...
try
{
// Stop the process.
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)
);
return;
} // 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 to the pipeline.
if (passThru)
{
message = String.Format(CultureInfo.CurrentCulture,
"Writing process \"{0}\" to pipeline",
processName);
WriteDebug(message);
WriteObject(process);
} // if (passThru...
} // SafeStopProcess
#endregion Helper Methods
#region Private Data
private bool yesToAll, noToAll;
/// <summary>
/// Partial list of the 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
} // namespace Microsoft.Samples.PowerShell.Commands