Bluetoothで周辺の機器を探索

bluetooth(BT)機器が周りにあるかどうかを探索します。
何に使うのかは、また今度に。

BT関連の情報ってなぜかあんまない。サンプルもあんまないし。
今回のターゲットはwindowsで、環境はVS2005です。

大まかにいえば、こんな感じ。

BluetoothDeviceSearchParams() で、BT機器の探索設定
BluetoothFindFirstDevice() で、BT機器を探索開始
BluetoothFindNextDevice() で、次のBT機器を取得
BluetoothFindDeviceClose() で、探索終了

サンプル。エラー処理とか入ってないので注意を。
動作テストとかもあんましてない。かなりやっつけ。
間違ってたら教えてください（＞＜。

  Dim btdi As New BluetoothDeviceInfo(0)

  Dim btdsp As New BluetoothDeviceSearchParams(0)
  btdsp.returnAuthenticated = 1
  btdsp.returnConnected = 1
  btdsp.returnRemembered = 1
  btdsp.issueInquiry = 1
  btdsp.returnUnknown = 1
  btdsp.timeoutMultiplier = 5
  Dim hRetFirstDev As IntPtr = BluetoothFindFirstDevice(btdsp, btdi)

  If hRetFirstDev <> IntPtr.Zero Then
    debug.print("address = " & btdi.address.ToString())
    debug.print("szName = " & btdi.name)

    Dim bNext As Boolean = False
    Do
      btdi = Nothing
      btdi = New BluetoothDeviceInfo(0)

      bNext = BluetoothFindNextDevice(hRetFirstDev, btdi)
      If bNext Then
        debug.print("address = " & btdi.address.ToString())
        debug.print("szName = " & btdi.name)
      End If
    Loop While bNext

    BluetoothFindDeviceClose(hRetFirstDev)
  End If

それぞれのAPIはこんな感じ。

  <StructLayout(LayoutKind.Sequential, pack:=4)> _
  Private Structure BluetoothDeviceSearchParams
    Public size As UInteger
    Public returnAuthenticated As Integer
    Public returnRemembered As Integer
    Public returnUnknown As Integer
    Public returnConnected As Integer
    Public issueInquiry As Integer
    Public timeoutMultiplier As Byte
    Public hRadio As IntPtr
    Sub New(ByVal dmy As Integer)
      Me.size = Marshal.SizeOf(Me)
    End Sub
  End Structure

  <DllImport("irprops.cpl", setlasterror:=True> _
  Private Shared Function BluetoothFindFirstDevice( _
    <[In]()> ByRef searchParams As BluetoothDeviceSearchParams, _
    ByRef deviceInfo As BluetoothDeviceInfo) As IntPtr
  End Function

  <DllImport("irprops.cpl", setlasterror:=True)> _
  Private Shared Function BluetoothFindNextDevice( _
    ByVal hFind As IntPtr, _
    ByRef pbtdi As BluetoothDeviceInfo) As Integer
  End Function

  <DllImport("irprops.cpl", setlasterror:=True)> _
  Private Shared Function BluetoothFindDeviceClose( _
    ByVal hFind As IntPtr) As Integer
  End Function

そして、BTデバイスの内容を格納する場所の定義。

  Private Const BT_MAX_NM_SZ = 248

  <StructLayout(LayoutKind.Sequential, Pack:=1)> _
  Private Structure BluetoothDeviceInfo
    Public size As UInteger
    Public address As BluetoothAddress
    Public classofDevice As UInteger
    Public connected As Boolean
    Public remembered As Boolean
    Public authenticated As Boolean
    Public lastSeen As SystemTime
    Public lastUsed As SystemTime
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=BT_MAX_NM_SZ)> _
    Public name As String
    Sub New(ByVal dmy As Integer)
      Me.name = New String("*"c, BT_MAX_NM_SZ)
      Me.lastSeen = New SystemTime
      Me.lastUsed = New SystemTime
      Me.size = Marshal.SizeOf(Me)
    End Sub
  End Structure

それ以外にも、以下のような構造体が必要です。

  <StructLayout(LayoutKind.Sequential, pack:=1)> _
  Private Structure SystemTime
    Public year As UShort
    Public month As UShort
    Public dayOfWeek As UShort
    Public day As UShort
    Public hour As UShort
    Public minute As UShort
    Public second As UShort
    Public milliseconds As UShort
  End Structure

  <StructLayout(LayoutKind.Sequential, pack:=1)> _
  Private Structure BluetoothAddress
    Public byte1 As Byte
    Public byte2 As Byte
    Public byte3 As Byte
    Public byte4 As Byte
    Public byte5 As Byte
    Public byte6 As Byte
    Public byte7 As Byte
    Public byte8 As Byte
    Public byte9 As Byte
    Public byte10 As Byte
    Public byte11 As Byte
    Public byte12 As Byte
    Public Overrides Function ToString() As String
      Return String.Format("{0}:{1}:{2}:{3}:{4}:{5}", _
             byte10.ToString("x"), byte9.ToString("x"), _
             byte8.ToString("x"), byte7.ToString("x"), _
             byte6.ToString("x"), byte5.ToString("x"))
    End Function
  End Structure

と、まぁ、こんな感じで。
周辺のBT機器を探索することができます（できるはず...）。

最新技術解説 入門Bluetooth (NEW COMPUTER TECHNOLOGY LIB.../ネットテクノロジーラボ

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