How to take pictures with USB webcam in Vb.net

See more:

VB

I am using Visual Basic 2010. Trying to reliably capture webcam images. It works some times - but about 50% of the time it pops up and asks for the video source. Even after this popup it only works sporatically.

Platform Windows 7 32bit, Vusial Basic 2010

Here is a sample of my code - taken from the examples posted on the web.

Private Sub OpenForm()
       Try

           Dim iHeight As Integer = Privew.Height
           Dim iWidth As Integer = Privew.Width

           '
           ' Open Preview window in picturebox
           '
           hHwnd = capCreateCaptureWindowA(iDevice, WS_VISIBLE Or WS_CHILD, 0, 0, 640, _
               480, Privew.Handle.ToInt32, 0)

           '
           ' Connect to device
           '
           If SendMessage(hHwnd, WM_CAP_DRIVER_CONNECT, iDevice, 0) Then
               '
               'Set the preview scale
               '
               SendMessage(hHwnd, WM_CAP_SET_SCALE, True, 0)

               '
               'Set the preview rate in milliseconds
               '
               SendMessage(hHwnd, WM_CAP_SET_PREVIEWRATE, 66, 0)

               '
               'Start previewing the image from the camera
               '
               SendMessage(hHwnd, WM_CAP_SET_PREVIEW, True, 0)

               '
               ' Resize window to fit in picturebox
               '
               SetWindowPos(hHwnd, HWND_BOTTOM, 0, 0, Privew.Width, Privew.Height, _
                       SWP_NOMOVE Or SWP_NOZORDER)
           End If
       Catch ex As Exception

       End Try

It only works occasionally - many times asking me for the 'Video Source' before it may or maynot show the image.

if any one know help me
Thanx in Advance