Hyper-V ゲスト OS の動作イメージサムネイルを取得するアクティビティ

以前 Hyper-V の管理とか操作を調べていて管理ツール上の動作イメージサムネイルをどうやって取得しているのかな、と思ったら WMI を利用して取得していることを教えてもらったので、ついでにアクティビティにしてみました。

PowerShell での方法はこちらの MSDN Blog に書いてありますが、これの WF アクティビティ化したものになります。やっている事としては、Msvm_ComputerSystem に対して該当するゲスト OS の情報を取得しにいき、結果から Msvm_VirtualSystemsettingData の情報を取得。その値を元に、再度 Msvm_ComputerSystem を取得、GetVirtualSystemThumbnailImage メソッドの情報を取得した上でメソッドを呼び出す。言葉で書くと非常にわかりずらいですが、大体このような感じで実行すれば、ゲスト OS のサムネイルが取得できます。

   1: Imports System.Activities

   2: Imports System.Management

   3:  

   4: Public MustInherit Class WMIExecuteActivityBase

   5:     Inherits AsyncCodeActivity

   6:  

   7:     Protected _target As String = ""

   8:     Protected _where As String = ""

   9:     Protected _service As String = ""

  10:  

  11:     Public Property Scope As InArgument(Of ManagementScope)

  12:     Public Property Results As OutArgument(Of List(Of Hashtable))

  13:  

  14:     Protected Delegate Function asyncExecuteWMIDelegate(ByVal target As String, ByVal whereCondition As String, ByVal wmScope As ManagementScope) As List(Of Hashtable)

  15:  

  16:     Protected Overrides Function BeginExecute(context As System.Activities.AsyncCodeActivityContext, callback As System.AsyncCallback, state As Object) As System.IAsyncResult

  17:         Dim currentScope = context.GetValue(Me.Scope)

  18:  

  19:         Dim asyncExecute = New asyncExecuteWMIDelegate(AddressOf ExecuteWMI)

  20:         context.UserState = asyncExecute

  21:  

  22:         Return asyncExecute.BeginInvoke(_target, _where, currentScope, callback, state)

  23:     End Function

  24:  

  25:     Protected Overrides Sub EndExecute(context As System.Activities.AsyncCodeActivityContext, result As System.IAsyncResult)

  26:         Dim asyncExecute = TryCast(context.UserState, asyncExecuteWMIDelegate)

  27:         Dim wmiResult = asyncExecute.EndInvoke(result)

  28:  

  29:         context.SetValue(Me.Results, wmiResult)

  30:     End Sub

  31:  

  32:     Protected Overridable Function ExecuteWMI(ByVal target As String, ByVal whereCondition As String, ByVal wmScope As ManagementScope) As List(Of Hashtable)

  33:  

  34:     End Function

  35:  

  36:     Protected Function CreateScope(ByVal wmScope As ManagementScope) As ManagementScope

  37:         If wmScope Is Nothing Then

  38:             wmScope = New ManagementScope("\\" + My.Computer.Name + "\root\" + _service)

  39:         End If

  40:         If Not wmScope.IsConnected Then wmScope.Connect()

  41:         Return wmScope

  42:     End Function

  43:  

  44: End Class

これがベースとなるアクティビティで、実際にはこれを継承した形で作成しました。

   1: Imports System.Activities

   2: Imports System.Management

   3: Imports System.Drawing

   4: Imports System.IO

   5:  

   6: Public Class WMIGetVMThumbnailActivity

   7:     Inherits WMIExecuteActivityBase

   8:  

   9:     Private _imageX As Integer = 320

  10:     Private _imageY As Integer = 240

  11:     Private _imageFile As String = ""

  12:  

  13:     Public Property VMName As InArgument(Of String)

  14:     Public Property ImageFileName As InArgument(Of String)

  15:     Public Property ImageSizeX As InArgument(Of Integer)

  16:     Public Property ImageSizeY As InArgument(Of Integer)

  17:  

  18:     Protected Overrides Function BeginExecute(ByVal context As System.Activities.AsyncCodeActivityContext, ByVal callback As System.AsyncCallback, ByVal state As Object) As System.IAsyncResult

  19:         MyBase._target = "Msvm_ComputerSystem "

  20:         MyBase._where = "Caption = '仮想マシン' and ElementName = '" + context.GetValue(Me.VMName) + "'"

  21:         MyBase._service = "virtualization"

  22:  

  23:         _imageX = context.GetValue(Me.ImageSizeX)

  24:         _imageY = context.GetValue(Me.ImageSizeY)

  25:         _imageFile = context.GetValue(Me.ImageFileName)

  26:  

  27:         Return MyBase.BeginExecute(context, callback, state)

  28:     End Function

  29:  

  30:     Protected Overrides Function ExecuteWMI(ByVal target As String, ByVal whereCondition As String, ByVal wmScope As System.Management.ManagementScope) As System.Collections.Generic.List(Of System.Collections.Hashtable)

  31:         Dim result As New List(Of Hashtable)

  32:         Try

  33:             wmScope = CreateScope(wmScope)

  34:  

  35:             Dim wmQuery As New ObjectQuery("SELECT * FROM " + target + " WHERE " + whereCondition)

  36:             Dim wmSearcher As New ManagementObjectSearcher(wmScope, wmQuery)

  37:             Dim wmVirtualSystem As ManagementObject = Nothing

  38:             For Each wmRes As ManagementObject In wmSearcher.Get

  39:                 For Each wmVir As ManagementObject In wmRes.GetRelated("Msvm_VirtualSystemsettingData")

  40:                     wmVirtualSystem = wmVir

  41:                     Exit For

  42:                 Next

  43:                 Exit For

  44:             Next

  45:             If wmVirtualSystem Is Nothing Then Return result

  46:  

  47:             Dim wmVsmsQuery As New ObjectQuery("SELECT * FROM " + target + " WHERE " + whereCondition)

  48:             Dim wmVsmsSearcher As New ManagementObjectSearcher(wmScope, wmVsmsQuery)

  49:             For Each wmVsms As ManagementObject In wmVsmsSearcher.Get

  50:                 Dim inParam = wmVsms.GetMethodParameters("GetVirtualSystemThumbnailImage")

  51:                 inParam("WidthPixels") = _imageX

  52:                 inParam("HeightPixels") = _imageY

  53:                 inParam("TargetSystem") = wmVirtualSystem.Path.Path

  54:  

  55:                 Dim wmMethodResult = wmVsms.InvokeMethod("GetVirtualSystemThumbnailImage", inParam, Nothing)

  56:                 Dim wmImage() = CType(wmMethodResult("ImageData"), Byte())

  57:                 My.Computer.FileSystem.WriteAllBytes(_imageFile, wmImage, False)

  58:                 Exit For

  59:             Next

  60:  

  61:         Catch ex As Exception

  62:             result.Clear()

  63:         End Try

  64:         Return result

  65:     End Function

  66:  

  67: End Class

このようなロジックになります。ただし、注意することが 1 点だけありまして、この方法で取得したイメージ（WriteAllBytes で保存している内容）は、画像の形式で言うと RAW となりますので、一般的な画像形式に変換してあげる必要があります。