Visual Basic

#Region "Webcam Defines"<br />
    Const WM_CAP As Short = &H400S<br />
<br />
    Const WM_CAP_DRIVER_CONNECT As Integer = WM_CAP + 10<br />
    Const WM_CAP_DRIVER_DISCONNECT As Integer = WM_CAP + 11<br />
    Const WM_CAP_EDIT_COPY As Integer = WM_CAP + 30<br />
<br />
    Const WM_CAP_SET_PREVIEW As Integer = WM_CAP + 50<br />
    Const WM_CAP_SET_PREVIEWRATE As Integer = WM_CAP + 52<br />
    Const WM_CAP_SET_SCALE As Integer = WM_CAP + 53<br />
    Const WS_CHILD As Integer = &H40000000<br />
    Const WS_VISIBLE As Integer = &H10000000<br />
    Const SWP_NOMOVE As Short = &H2S<br />
    Const SWP_NOSIZE As Short = 1<br />
    Const SWP_NOZORDER As Short = &H4S<br />
    Const HWND_BOTTOM As Short = 1<br />
<br />
    Dim iDevice As Integer = 0<br />
    Friend WithEvents SerialPort1 As System.IO.Ports.SerialPort<br />
    Friend WithEvents Button3 As System.Windows.Forms.Button<br />
    Friend WithEvents Timer1 As System.Windows.Forms.Timer<br />
    Friend WithEvents Button4 As System.Windows.Forms.Button<br />
    ' Current device ID<br />
    Dim hHwnd As Integer ' Handle to preview window<br />
<br />
    Declare Function SendMessage Lib "user32" Alias "SendMessageA" _<br />
        (ByVal hwnd As Integer, ByVal wMsg As Integer, ByVal wParam As Integer, _<br />
        <MarshalAs(UnmanagedType.AsAny)> ByVal lParam As Object) As Integer<br />
<br />
    Declare Function SetWindowPos Lib "user32" Alias "SetWindowPos" (ByVal hwnd As Integer, _<br />
        ByVal hWndInsertAfter As Integer, ByVal x As Integer, ByVal y As Integer, _<br />
        ByVal cx As Integer, ByVal cy As Integer, ByVal wFlags As Integer) As Integer<br />
<br />
    Declare Function DestroyWindow Lib "user32" (ByVal hndw As Integer) As Boolean<br />
<br />
    Declare Function capCreateCaptureWindowA Lib "avicap32.dll" _<br />
        (ByVal lpszWindowName As String, ByVal dwStyle As Integer, _<br />
        ByVal x As Integer, ByVal y As Integer, ByVal nWidth As Integer, _<br />
        ByVal nHeight As Short, ByVal hWndParent As Integer, _<br />
        ByVal nID As Integer) As Integer<br />
<br />
    Declare Function capGetDriverDescriptionA Lib "avicap32.dll" (ByVal wDriver As Short, _<br />
        ByVal lpszName As String, ByVal cbName As Integer, ByVal lpszVer As String, _<br />
        ByVal cbVer As Integer) As Boolean<br />
<br />
#End Region

    Private Sub LoadDeviceList()<br />
        Dim strName As String = Space(100)<br />
        Dim strVer As String = Space(100)<br />
        Dim bReturn As Boolean<br />
        Dim x As Integer = 0<br />
        ' Loads name of all avialable devices into the Video_Sources<br />
        Do<br />
            bReturn = capGetDriverDescriptionA(x, strName, 100, strVer, 100)<br />
            If bReturn Then Video_Sources.Items.Add(strName.Trim)<br />
            x += 1<br />
        Loop Until bReturn = False<br />
        If Video_Sources.Items.Count > 0 Then<br />
            Video_Sources.SelectedIndex = 0<br />
        Else<br />
            Video_Sources.Items.Add("No Capture Device")<br />
        End If<br />
    End Sub<br />
<br />
    Private Sub OpenPreviewWindow()<br />
        Dim iHeight As Integer = picCapture.Height<br />
        Dim iWidth As Integer = picCapture.Width<br />
<br />
        hHwnd = capCreateCaptureWindowA(iDevice, WS_VISIBLE Or WS_CHILD, 0, 0, 640, _<br />
            480, picCapture.Handle.ToInt32, 0)<br />
<br />
        If SendMessage(hHwnd, WM_CAP_DRIVER_CONNECT, iDevice, 0) Then<br />
            SendMessage(hHwnd, WM_CAP_SET_SCALE, True, 0)<br />
            SendMessage(hHwnd, WM_CAP_SET_PREVIEWRATE, 66, 0)<br />
            SendMessage(hHwnd, WM_CAP_SET_PREVIEW, True, 0)<br />
            SetWindowPos(hHwnd, HWND_BOTTOM, 0, 0, picCapture.Width, picCapture.Height, _<br />
                    SWP_NOMOVE Or SWP_NOZORDER)<br />
        Else<br />
            DestroyWindow(hHwnd)<br />
<br />
        End If<br />
    End Sub <br />
<br />
    Private Sub ClosePreviewWindow()<br />
        SendMessage(hHwnd, WM_CAP_DRIVER_DISCONNECT, iDevice, 0)<br />
        DestroyWindow(hHwnd)<br />
    End Sub

  iDevice = Video_Sources.SelectedIndex<br />
        OpenPreviewWindow()<br />
<br />
        Video_Sources.SendToBack()<br />
        Change_Video_Apply.SendToBack()

ClosePreviewWindow()<br />
      Video_Sources.BringToFront()<br />
      Change_Video_Apply.BringToFront()

<br />
    Private Sub dg_RowChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)<br />
        Try<br />
            Me.Cursor = System.Windows.Forms.Cursors.WaitCursor<br />
            idCol.ReadOnly = True<br />
            If "condition" Then<br />
                idCol.ReadOnly = False<br />
            End If<br />
        Catch ex As Exception<br />
            MessageHandler.HandleError(ex)<br />
        Finally<br />
            Me.Cursor = System.Windows.Forms.Cursors.Default<br />
        End Try<br />
    End Sub<br />