#TouchKeyboard制御

    Const WM_SYSCOMMAND As Integer = &H112
    Const SC_CLOSE As Integer = &HF060

    Const AlphanumericHalfWidth As Integer = 40
    Const TelephoneNumber As Integer = 32

    <DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
    Public Shared Function SendMessage(ByVal hwnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
    End Function

    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function PostMessage(ByVal hWnd As IntPtr, ByVal Msg As UInteger, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Boolean
    End Function

    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function FindWindow( _
    ByVal lpClassName As String, _
    ByVal lpWindowName As String) As IntPtr
    End Function

    <DllImport("msctf.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function SetInputScope(ByVal hwnd As IntPtr, ByVal inputscope As IntPtr) As IntPtr

    End Function
''' <summary>
    ''' ソフトウェアキーボードを起動
    ''' </summary>
    Private Sub OpenKeyboard()
        Process.Start("c:\program files\common files\microsoft shared\ink\tabtip.exe")
    End Sub

    ''' <summary>
    ''' ソフトウェアキーボードを終了
    ''' </summary>
    Private Sub CloseKeyboard()

        'ソフトウェアキーボードのウィンドウを探す
        Dim hWnd As IntPtr = FindWindow("IPTip_Main_Window", "")

        '見つけたら閉じるメッセージを送信
        If hWnd <> IntPtr.Zero Then
            Call SendMessage(hWnd, WM_SYSCOMMAND, SC_CLOSE, 0)
        End If
    End Sub

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
        Dim hwnd As IntPtr
        'TextBox1上touchkeyboardのタイプを数値モードに
        hwnd = Me.TextBox1.Handle
        SetInputScope(hwnd, TelephoneNumber )
End Sub

Private Sub TextBox1_GotFocus(sender As Object, e As EventArgs) Handles TextBox1.GotFocus
        OpenKeyboard()
    End Sub

*~~TABLETTIPLibがWindows7.1 SDK?にあるらしい。~~探してみたが見つからない。TabTip.exeを参照に追加するといった記述を見つけたがWindows8のTabTip.exeではできないみたいだ。

        Dim TabTIP As TABLETTIPLib.UIHostClass = New TABLETTIPLib.UIHostClass()
        TabTIP.ShowWnd(True) '消すときはFalse

touchkeyboardが画面幅いっぱいだと表示されるときにフォームが
小さくされてしまうが、戻すタイミング（touchkeyboardが消えるタイミング）
はどうしたらわかるのだろうか。

#物理キーボード検出

 Public Enum RawInputDeviceType As UInteger
        MOUSE = 0
        KEYBOARD = 1
        HID = 2
    End Enum
    <StructLayout(LayoutKind.Sequential)> _
    Public Structure RAWINPUTDEVICELIST
        Public hDevice As IntPtr
        Public dwType As IntPtr
    End Structure

    <DllImport("user32.dll", CharSet:=CharSet.Auto,
     EntryPOint:="GetRawInputDeviceList", SetLastError:=True)> _
    Private Shared Function GetRawInputDeviceList(ByVal pRawInputDeviceList As  _
    IntPtr, ByRef puiNumDevices As IntPtr, ByVal cbSize As IntPtr) As IntPtr
    End Function

    Private _nummouse As Integer = 0
    Private _numkeyboard As Integer = 0
    Private _numhid As Integer = 0

    Public Sub New()
        Dim devlist As RAWINPUTDEVICELIST
        Dim buf As IntPtr
        Dim i As Integer
        Dim bufsz As Integer
        Dim dsz As Integer
        Dim ret As Integer

        dsz = Marshal.SizeOf(GetType(RAWINPUTDEVICELIST))

        ret = GetRawInputDeviceList(IntPtr.Zero, bufsz, dsz)
        buf = Marshal.AllocHGlobal(Marshal.SizeOf(GetType(RAWINPUTDEVICELIST)) * bufsz)
        ret = GetRawInputDeviceList(buf, bufsz, dsz)
        For i = 0 To ret - 1
            Dim p As IntPtr
            p = New IntPtr(buf.ToInt32 + Marshal.SizeOf(GetType(RAWINPUTDEVICELIST)) * i)

            devlist = CType(Marshal.PtrToStructure(p, GetType(RAWINPUTDEVICELIST)), RAWINPUTDEVICELIST)
            If (devlist.dwType = phykey.RawInputDeviceType.KEYBOARD) Then
                _numkeyboard = _numkeyboard + 1
            End If
        Next
        Marshal.FreeHGlobal(buf)

    End Sub

ノーパソで試したところ１が取れた。タブレットはどうなるんだろ。
USBキーボードやBTキーボードだとHIDになるのかしら？？
タブレットで試したところキーボードない状態なのに２が返ってきたのでこれではダメそう。

Detect keyboard presence in Windows 8 desktop program
なんかまんまの書き込みを見つけたのでこれもやってみるかな。

#画面ローテーション
解像度の変更イベントで拾えるらしい。

System.Eventsクラス