Preview ภาพจาก webcam แล้วจอดำ vb 2008 แต่บันทึกภาพกับถ่ายภาพได้แล้วครับ

Imports System
Imports System.IO
Imports System.Runtime.InteropServices
Imports Microsoft.Win32

Public Class Form1
Inherits System.Windows.Forms.Form

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 CamSource As Integer
'---used as a window handle---
Dim hWnd As Integer

Private Sub cameraSource()
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
ListBox1.Items.Add(DriverName.Trim)
End If
Next
End Sub
Private Sub previewCamera(ByVal pbCtrl As PictureBox)
hWnd = capCreateCaptureWindowA(CamSource, _
WS_VISIBLE Or WS_CHILD, 0, 0, 0, _
0, pbCtrl.Handle.ToInt32, 0)
If SendMessage( _
hWnd, WM_CAP_DRIVER_CONNECT, _
CamSource, 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
Private Sub stopPreviewCamera()
SendMessage(hWnd, WM_CAP_DRIVER_DISCONNECT, CamSource, 0)
DestroyWindow(hWnd)
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
cameraSource()
btnPreview.Enabled = False
btnStopPreview.Enabled = False
btnRecord.Enabled = False
btnStopRecord.Enabled = False
btnCapture.Enabled = False
Me.PictureBox1.SizeMode = PictureBoxSizeMode.StretchImage
Me.SaveFileDialog1.FileName = "Kasem"
Me.SaveFileDialog1.Filter = "PNG|*.png"
End Sub

Private Sub ListBox1_DoubleClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.DoubleClick
Label1.Visible = False
previewCamera(PictureBox1)
btnStopPreview.Enabled = True
btnPreview.Enabled = False
btnRecord.Enabled = True
btnCapture.Enabled = True
End Sub

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
CamSource = ListBox1.SelectedIndex
'---preview the selected video source
End Sub
' recording
Private Sub btnRecord_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnRecord.Click
btnStopRecord.Enabled = True
btnRecord.Enabled = False
SendMessage(hWnd, WM_CAP_SEQUENCE, 0, 0)
End Sub

' stop recording and ask to save video
Private Sub btnStopRecord_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStopRecord.Click
Dim save As Integer
save = MsgBox("Do you want to save your recording video", MsgBoxStyle.YesNo + MsgBoxStyle.Information, "Recording Video")
If (save = MsgBoxResult.Yes) Then
Dim saveName As New SaveFileDialog
saveName.Filter = "Avi file(*.avi)|*.avi"
If saveName.ShowDialog = DialogResult.OK Then
' SendMessage(hWnd, WM_CAP_FILE_SAVEAS, 0, "C:\RecordedVideo.avi")
SendMessage(hWnd, WM_CAP_FILE_SAVEAS, 0, saveName.FileName)
End If
End If
Me.Cursor = System.Windows.Forms.Cursors.Default
btnRecord.Enabled = True
btnStopRecord.Enabled = False
End Sub

' preview
Private Sub btnPreview_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPreview.Click
CamSource = ListBox1.SelectedIndex
previewCamera(PictureBox1)
btnPreview.Enabled = False
btnStopPreview.Enabled = True
End Sub

'stop preview
Private Sub btnStopPreview_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStopPreview.Click
stopPreviewCamera()
btnPreview.Enabled = True
btnStopPreview.Enabled = False
btnCapture.Enabled = False
End Sub

Private Sub btnCapture_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCapture.Click
Dim data As IDataObject
Dim bmap As Image
SendMessage(hWnd, WM_CAP_EDIT_COPY, 0, 0)
data = Clipboard.GetDataObject()
If data.GetDataPresent(GetType(System.Drawing.Bitmap)) Then
bmap = CType(data.GetData(GetType(System.Drawing.Bitmap)), Image)
Me.PictureBox1.Image = bmap
stopPreviewCamera()
Me.btnPreview.Enabled = True
If Me.SaveFileDialog1.ShowDialog = DialogResult.OK Then
bmap.Save(Me.SaveFileDialog1.FileName, Imaging.ImageFormat.Png)
End If

'If Me.SaveFileDialog1.ShowDialog = DialogResult.OK Then
' bmap.Save(Me.SaveFileDialog1.FileName, Imaging.ImageFormat.Bmp)
'End If

previewCamera(PictureBox1)
End If
End Sub

End Class

bY>>>  http://kasem-mesak.blogspot.com/2010/12/vbnet-web-camera.html

บันทึก VDO กับถ่ายภาพได้แล้ว แต่มันไม่มีภาพ ตอน preview จอเป็นสีดำตลอดเลยครับ ใครเคยเจอปัญหานี่บ้าง มีวิธีแก้ไขไหมครับ