StopProcessSample04 (VB.NET) Sample Code
Here is the complete VB.NET sample code for the StopProc04 sample cmdlet. This is the code for the Stop-Process cmdlet described in Adding Parameter Sets to a Cmdlet. The Stop-Process cmdlet is designed to stop processes that are retrieved using the Get-Proc cmdlet (described in Creating Your First Cmdlet).
Note
You can download the VB.NET (stopprocesssample04.vb) source file for this Stop-Proc cmdlet using the Microsoft Windows Software Development Kit for Windows Vista and .NET Framework 3.0 Runtime Components. For download instructions, see How to Install Windows PowerShell and Download the Windows PowerShell SDK.
The downloaded source files are available in the <PowerShell Samples> directory.
Imports System
Imports System.Diagnostics
Imports System.Collections
Imports Win32Exception = System.ComponentModel.Win32Exception
Imports System.Management.Automation 'Windows PowerShell namespace
Imports System.ComponentModel
Imports System.Globalization
Namespace Microsoft.Samples.PowerShell.Commands
' This sample introduces parameter sets, the input object and
' DefaultParameterSet.
#Region "StopProcCommand"
''' <summary>
''' Class that implements the stop-proc cmdlet.
''' </summary>
<Cmdlet(VerbsLifecycle.Stop, "Proc", DefaultParameterSetName:="ProcessId", _
SupportsShouldProcess:=True)> _
Public Class StopProcCommand
Inherits PSCmdlet
#Region "Parameters"
''' <summary>
''' The list of process names on which this cmdlet will work.
''' </summary>
<Parameter(Position:=0, ParameterSetName:="ProcessName", _
Mandatory:=True, _
ValueFromPipeline:=True, ValueFromPipelineByPropertyName:=True, _
HelpMessage:="The name of one or more processes to stop. " & _
"Wildcards are permitted."), [Alias]("ProcessName")> _
Public Property Name() As String()
Get
Return processNames
End Get
Set(ByVal value As String())
processNames = value
End Set
End Property
Private processNames() As String
''' <summary>
''' Overrides the ShouldContinue check to force stop operation.
''' This option should always be used with caution.
''' </summary>
<Parameter()> _
Public Property Force() As SwitchParameter
Get
Return myForce
End Get
Set(ByVal value As SwitchParameter)
myForce = value
End Set
End Property
Private myForce As Boolean
''' <summary>
''' Common parameter to determine if the process should pass the
''' object down the pipeline after the process has been stopped.
''' </summary>
<Parameter( _
HelpMessage:= _
"If set the process(es) will be passed to the pipeline " & _
"after stopping them.")> _
Public Property PassThru() As SwitchParameter
Get
Return myPassThru
End Get
Set(ByVal value As SwitchParameter)
myPassThru = value
End Set
End Property
Private myPassThru As Boolean
''' <summary>
''' The list of process IDs on which this cmdlet will work.
''' </summary>
<Parameter(ParameterSetName:="ProcessId", _
Mandatory:=True, _
ValueFromPipelineByPropertyName:=True, _
ValueFromPipeline:=True), [Alias]("ProcessId")> _
Public Property Id() As Integer()
Get
Return processIds
End Get
Set(ByVal value As Integer())
processIds = value
End Set
End Property
Private processIds() As Integer
''' <summary>
''' An array of Process objects from the stream to stop.
''' </summary>
''' <value>Process objects</value>
<Parameter(ParameterSetName:="InputObject", _
Mandatory:=True, ValueFromPipeline:=True)> _
Public Property InputObject() As Process()
Get
Return myInputObject
End Get
Set(ByVal value As Process())
myInputObject = value
End Set
End Property
Private myInputObject() As Process
#End Region
#Region "CmdletOverrides"
''' <summary>
''' For each of the requested processnames:
''' 1) check it's not a special process
''' 2) attempt to stop that process.
''' If no process requested, then nothing occurs.
''' </summary>
Protected Overrides Sub ProcessRecord()
Select Case ParameterSetName
Case "ProcessName"
ProcessByName()
Case "ProcessId"
ProcessById()
Case "InputObject"
Dim process As Process
For Each process In myInputObject
SafeStopProcess(process)
Next process
Case Else
Throw New ArgumentException("Bad ParameterSet Name")
End Select
End Sub 'ProcessRecord ' ProcessRecord
#End Region
#Region "Helper Methods"
''' <summary>
''' Returns all processes with matching names.
''' </summary>
''' <param name="processName">
''' The name of the process(es) to return
''' </param>
''' <param name="allProcesses">An array of all
''' machine processes.</param>
''' <returns>An array of matching processes.</returns>
Friend Function SafeGetProcessesByName(ByVal processName As String, _
ByRef allProcesses As ArrayList) As ArrayList
' Create and array to store the matching processes.
Dim matchingProcesses As New ArrayList()
' Create the wildcard for pattern matching.
Dim options As WildcardOptions = WildcardOptions.IgnoreCase Or _
WildcardOptions.Compiled
Dim wildcard As New WildcardPattern(processName, options)
' Walk all of the machine processes.
Dim process As Process
For Each process In allProcesses
Dim processNameToMatch As String = Nothing
Try
processNameToMatch = process.ProcessName
Catch e As Win32Exception
' Remove the process from the list so that it is not
' checked again.
allProcesses.Remove(process)
Dim message As String = _
String.Format(CultureInfo.CurrentCulture, _
"The process ""{0}"" could not be found", processName)
WriteVerbose(message)
WriteError(New ErrorRecord(e, _
"ProcessNotFound", ErrorCategory.ObjectNotFound, _
processName))
GoTo ContinueForEach1
End Try
If Not wildcard.IsMatch(processNameToMatch) Then
GoTo ContinueForEach1
End If
matchingProcesses.Add(process)
ContinueForEach1:
Next process
Return matchingProcesses
End Function 'SafeGetProcessesByName
''' <summary>
''' Safely stops a named process. Used as standalone function
''' to declutter ProcessRecord method.
''' </summary>
''' <param name="process">The process to stop.</param>
Private Sub SafeStopProcess(ByVal process As Process)
Dim processName As String = Nothing
Try
processName = process.ProcessName
Catch e As Win32Exception
WriteError(New ErrorRecord(e, "ProcessNotFound", _
ErrorCategory.OpenError, processName))
Return
End Try
' Confirm the operation first.
' This is always false if WhatIf is set.
If Not ShouldProcess(String.Format(CultureInfo.CurrentCulture, _
"{0} ({1})", processName, process.Id)) Then
Return
End If
' Make sure the user really wants to stop a critical
' process and possibly stop the machine.
Dim criticalProcess As Boolean = _
criticalProcessNames.Contains( _
processName.ToLower(CultureInfo.CurrentCulture))
Dim message As String = Nothing
If criticalProcess AndAlso Not myForce Then
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 Not ShouldContinue(message, "Warning!", yesToAll, noToAll) Then
Return
End If
End If
' Display a warning information if stopping a critical
' process
If criticalProcess Then
message = String.Format(CultureInfo.CurrentCulture, _
"Stopping the critical process ""{0}"".", processName)
WriteWarning(message)
End If
Try
' Stop the process.
process.Kill()
Catch e As Exception
If TypeOf e Is Win32Exception OrElse TypeOf e Is SystemException _
OrElse TypeOf e Is InvalidOperationException Then
' This process could not be stopped so write
' a non-terminating error.
WriteError(New ErrorRecord(e, _
"CouldNotStopProcess", ErrorCategory.CloseError, process))
Return
Else
Throw
End If
End Try
' Write a user-level message to the pipeline. These 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, _
"Stopped process ""{0}"", pid {1}.", processName, process.Id)
WriteVerbose(message)
' If the -PassThru command line argument is
' specified, pass the terminated process on.
If myPassThru Then
' Write a debug message to the host which will be helpful
' in troubleshooting a problem. All debug messages
' will appear with the -Debug option
message = String.Format(CultureInfo.CurrentCulture, _
"Writing process ""{0}"" to pipeline", processName)
WriteDebug(message)
WriteObject(process)
End If
End Sub 'SafeStopProcess
''' <summary>
''' Stop processes based on their names (using the
''' ParameterSetName as ProcessName)
''' </summary>
Private Sub ProcessByName()
Dim allProcesses As ArrayList = Nothing
' Get a list of all processes.
Try
allProcesses = New ArrayList(Process.GetProcesses())
Catch ioe As InvalidOperationException
MyBase.ThrowTerminatingError(New ErrorRecord(ioe, _
"UnableToAccessProcessList", _
ErrorCategory.InvalidOperation, Nothing))
End Try
' If a name parameter is passed to cmdlet, get
' the associated process(es).
' Write a non-terminating error for failure to
' retrieve a process
Dim name As String
For Each name In processNames
' The allProcesses array list is passed as a reference because
' any process whose name cannot be obtained will be removed
' from the list so that its not compared the next time.
Dim processes As ArrayList = SafeGetProcessesByName(name, _
allProcesses)
' If no processes were found write a non-terminating error.
If processes.Count = 0 Then
WriteError(New ErrorRecord( _
New Exception("Process not found."), _
"ProcessNotFound", ErrorCategory.ObjectNotFound, name))
Else
' Otherwise terminate all processes in the list.
Dim process As Process
For Each process In processes
SafeStopProcess(process)
Next process
End If
Next name
End Sub 'ProcessByName
''' <summary>
''' Stop processes based on their ids (using the
''' ParameterSetName as ProcessIds)
''' </summary>
Friend Sub ProcessById()
Dim processId As Integer
For Each processId In processIds
Dim process As Process = Nothing
Try
process = System.Diagnostics.Process.GetProcessById(processId)
' Write a debug message to the host which will be helpful
' in troubleshooting a problem. All debug messages
' will appear with the -Debug option
Dim message As String = String.Format( _
CultureInfo.CurrentCulture, _
"Acquired process for pid : {0}", process.Id)
WriteDebug(message)
Catch ae As ArgumentException
Dim message As String = String.Format( _
CultureInfo.CurrentCulture, _
"The process id {0} could not be found", processId)
WriteVerbose(message)
WriteError(New ErrorRecord(ae, _
"ProcessIdNotFound", _
ErrorCategory.ObjectNotFound, processId))
GoTo ContinueForEach1
End Try
SafeStopProcess(process)
ContinueForEach1:
Next processId
End Sub 'ProcessById ' ProcessById
#End Region
#Region "Private Data"
Private yesToAll, noToAll As Boolean
''' <summary>
''' Partial list of critical processes that should not be
''' stopped. Lower case is used for case insensitive matching.
''' </summary>
Private criticalProcessNames As New ArrayList( _
New String() {"system", "winlogon", "spoolsv", "calc"})
#End Region
End Class 'StopProcCommand
#End Region
#Region "PowerShell snap-in" '
''' <summary>
''' Create this sample as a PowerShell snap-in
''' </summary>
<RunInstaller(True)> _
Public Class StopProcPSSnapIn04
Inherits PSSnapIn
''' <summary>
''' Create an instance of the StopProcPSSnapIn04
''' </summary>
Public Sub New()
End Sub 'New
''' <summary>
''' Get a name for this PowerShell snap-in. This name will
''' be used in registering this PowerShell snap-in.
''' </summary>
Public Overrides ReadOnly Property Name() As String
Get
Return "StopProcPSSnapIn04"
End Get
End Property
''' <summary>
''' Vendor information for this PowerShell snap-in.
''' </summary>
Public Overrides ReadOnly Property Vendor() As String
Get
Return "Microsoft"
End Get
End Property
''' <summary>
''' Gets resource information for vendor. This is a string of format:
''' resourceBaseName,resourceName.
''' </summary>
Public Overrides ReadOnly Property VendorResource() As String
Get
Return "StopProcPSSnapIn04,Microsoft"
End Get
End Property
''' <summary>
''' Description of this PowerShell snap-in.
''' </summary>
Public Overrides ReadOnly Property Description() As String
Get
Return "This is a PowerShell snap-in that includes " & _
"the stop-proc cmdlet."
End Get
End Property
End Class 'StopProcPSSnapIn04
#End Region
End Namespace
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