Imports System.Runtime.InteropServicesPublic Class Form1
Const WM_CAP_START = &H400S
Const WS_CHILD = &H40000000
Const WS_VISIBLE = &H10000000
Const WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10
Const WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11
Const WM_CAP_EDIT_COPY = WM_CAP_START + 30
Const WM_CAP_SEQUENCE = WM_CAP_START + 62
Const WM_CAP_FILE_SAVEAS = WM_CAP_START + 23
Const WM_CAP_SET_SCALE = WM_CAP_START + 53
Const WM_CAP_SET_PREVIEWRATE = WM_CAP_START + 52
Const WM_CAP_SET_PREVIEW = WM_CAP_START + 50
Const SWP_NOMOVE = &H2S
Const SWP_NOSIZE = 1
Const SWP_NOZORDER = &H4S
Const HWND_BOTTOM = 1
'--The capGetDriverDescription function retrieves the version
' description of the capture driver--
Declare Function capGetDriverDescriptionA Lib "avicap32.dll" _
(ByVal wDriverIndex As Short, _
ByVal lpszName As String, ByVal cbName As Integer, _
ByVal lpszVer As String, _
ByVal cbVer As Integer) As Boolean
'--The capCreateCaptureWindow function creates a capture window--
Declare Function capCreateCaptureWindowA Lib "avicap32.dll" _
(ByVal lpszWindowName As String, ByVal dwStyle As Integer, _
ByVal x As Integer, ByVal y As Integer, ByVal nWidth As Integer, _
ByVal nHeight As Short, ByVal hWnd As Integer, _
ByVal nID As Integer) As Integer
'--This function sends the specified message to a window or windows--
Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hwnd As Integer, ByVal Msg As Integer, _
ByVal wParam As Integer, _
<MarshalAs(UnmanagedType.AsAny)> ByVal lParam As Object) As Integer
'--Sets the position of the window relative to the screen buffer--
Declare Function SetWindowPos Lib "user32" Alias "SetWindowPos" _
(ByVal hwnd As Integer, _
ByVal hWndInsertAfter As Integer, ByVal x As Integer, _
ByVal y As Integer, _
ByVal cx As Integer, ByVal cy As Integer, _
ByVal wFlags As Integer) As Integer
'--This function destroys the specified window--
Declare Function DestroyWindow Lib "user32" _
(ByVal hndw As Integer) As Boolean
'---used to identify the video source---
Dim VideoSource As Integer
'---used as a window handle---
Dim hWnd As Integer
'---list all the various video sources---
Private Sub Form1_Load( _
ByVal sender As System.Object, _
ByVal e As System.EventArgs)
bntStartRecording.Enabled = True
btnStopRecording.Enabled = False
'---list all the video sources---
ListVideoSources()
End Sub
Private Sub ListVideoSources()
Dim DriverName As String = Space(80)
Dim DriverVersion As String = Space(80)
For i As Integer = 0 To 9
If capGetDriverDescriptionA(i, DriverName, 80, _
DriverVersion, 80) Then
istVideosources.Items.Add(DriverName.Trim)
End If
Next
End Sub
'---list all the video sources---
Private Sub lstVideoSources_SelectedIndexChanged( _
ByVal sender As System.Object, ByVal e As System.EventArgs) _
Handles istVideosources.SelectedIndexChanged
'---check which video source is selected---
VideoSource = istVideosources.SelectedIndex
'---preview the selected video source
PreviewVideo(PictureBox1)
End Sub
'---preview the selected video source---
Private Sub PreviewVideo(ByVal pbCtrl As PictureBox)
hWnd = capCreateCaptureWindowA(VideoSource, _
WS_VISIBLE Or WS_CHILD, 0, 0, 0, _
0, pbCtrl.Handle.ToInt32, 0)
If SendMessage( _
hWnd, WM_CAP_DRIVER_CONNECT, _
VideoSource, 0) Then
'---set the preview scale---
SendMessage(hWnd, WM_CAP_SET_SCALE, True, 0)
'---set the preview rate (ms)---
SendMessage(hWnd, WM_CAP_SET_PREVIEWRATE, 30, 0)
'---start previewing the image---
SendMessage(hWnd, WM_CAP_SET_PREVIEW, True, 0)
'---resize window to fit in PictureBox control---
SetWindowPos(hWnd, HWND_BOTTOM, 0, 0, _
pbCtrl.Width, pbCtrl.Height, _
SWP_NOMOVE Or SWP_NOZORDER)
Else
'--error connecting to video source---
DestroyWindow(hWnd)
End If
End Sub
'---stop the preview window---
Private Sub btnStopCamera_Click( _
ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles btnStopCamera.Click
StopPreviewWindow()
End Sub
'--disconnect from video source---
Private Sub StopPreviewWindow()
SendMessage(hWnd, WM_CAP_DRIVER_DISCONNECT, VideoSource, 0)
DestroyWindow(hWnd)
End Sub
'---Start recording the video---
Private Sub btnStartRecording_Click( _
ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles bntStartRecording.Click
bntStartRecording.Enabled = False
btnStopRecording.Enabled = True
'---start recording---
SendMessage(hWnd, WM_CAP_SEQUENCE, 0, 0)
End Sub
Private Sub btnStopRecording_Click( _
ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles btnStopRecording.Click
bntStartRecording.Enabled = True
btnStopRecording.Enabled = False
'---save the recording to file---
SendMessage(hWnd, WM_CAP_FILE_SAVEAS, 0, _
"C:\RecordedVideo.avi")
End Sub
Private Sub PictureBox1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PictureBox1.Click
End Sub
Private Sub bntStartRecording_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bntStartRecording.Click
End Sub
Private Sub istVideosources_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles istVideosources.SelectedIndexChanged
End Sub
End Class
