Hi,
Here is a class I have been working on that creates a capture window
inside a picturebox. In the opencapturewindow method pass in the handle of
the picturebox to place the window and the height and width of the window.
GetImage copies the image to the clipboard then returns the image as a
bitmap. Hope this helps.
Imports System.Runtime.InteropServices
Imports System.Windows.Forms
Imports System.Drawing
Public Class WebcamCaptureImage
Const WM_CAP As Short = &H400S
Const WM_CAP_DRIVER_CONNECT As Integer = WM_CAP + 10
Const WM_CAP_DRIVER_DISCONNECT As Integer = WM_CAP + 11
Const WM_CAP_EDIT_COPY As Integer = WM_CAP + 30
Const WM_CAP_SET_PREVIEW As Integer = WM_CAP + 50
Const WM_CAP_SET_PREVIEWRATE As Integer = WM_CAP + 52
Const WM_CAP_SET_SCALE As Integer = WM_CAP + 53
Const WS_CHILD As Integer = &H40000000
Const WS_VISIBLE As Integer = &H10000000
Const SWP_NOMOVE As Short = &H2S
Const SWP_NOSIZE As Short = 1
Const SWP_NOZORDER As Short = &H4S
Const HWND_BOTTOM As Short = 1
Dim iDevice As Integer = 0 ' Current device ID
Dim hHwnd As Integer ' Handle to preview window
Dim mDevice As Collection
Dim bPreviewing As Boolean = False
Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hwnd As Integer, ByVal wMsg As Integer, ByVal wParam As Integer, _
ByVal lParam As Integer) As Integer
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
Declare Function DestroyWindow Lib "user32" (ByVal hndw As Integer) As
Boolean
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 hWndParent As Integer, _
ByVal nID As Integer) As Integer
Declare Function capGetDriverDescriptionA Lib "avicap32.dll" (ByVal wDriver
As Short, _
ByVal lpszName As String, ByVal cbName As Integer, ByVal lpszVer As String,
_
ByVal cbVer As Integer) As Boolean
Private Sub LoadDeviceList()
Dim strName As String = Space(100)
Dim strVer As String = Space(100)
Dim bReturn As Boolean
Dim x As Integer = 0
'
' Load name of all avialable devices into the lstDevices
'
mDevice = New Collection
Do
'
' Get Driver name and version
'
bReturn = capGetDriverDescriptionA(x, strName, 100, strVer, 100)
'
' If there was a device add device name to the list
'
If bReturn Then
Dim wci As New WebcamInfo
With wci
..Device = strName
..Version = strVer
End With
mDevice.Add(wci)
End If
x += 1
Loop Until bReturn = False
End Sub
Public Function OpenPreviewWindow(ByVal hWndCapture As IntPtr, ByVal h As
Integer, ByVal w As Integer) As Boolean
'
' Open Preview window in picturebox
'
If bPreviewing Then ClosePreviewWindow()
hHwnd = capCreateCaptureWindowA(iDevice, WS_VISIBLE Or WS_CHILD, 0, 0, 320,
_
240, hWndCapture.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, w, h, _
SWP_NOMOVE Or SWP_NOZORDER)
bPreviewing = True
Else
'
' Error connecting to device close window
'
DestroyWindow(hHwnd)
bPreviewing = False
End If
Return bPreviewing
End Function
Public Sub ClosePreviewWindow()
'
' Disconnect from device
'
SendMessage(hHwnd, WM_CAP_DRIVER_DISCONNECT, iDevice, 0)
'
' close window
'
DestroyWindow(hHwnd)
End Sub
Public Function GetImage() As Bitmap
Dim data As IDataObject
Dim bmap As Bitmap
If Not bPreviewing Then Return Nothing
'
' Copy image to clipboard
'
SendMessage(hHwnd, WM_CAP_EDIT_COPY, 0, 0)
'
' Get image from clipboard and convert it to a bitmap
'
data = Clipboard.GetDataObject()
If data.GetDataPresent(GetType(System.Drawing.Bitmap) ) Then
bmap = CType(data.GetData(GetType(System.Drawing.Bitmap)) , Bitmap)
ClosePreviewWindow()
Return bmap
End If
Return Nothing
End Function
Protected Overrides Sub Finalize()
If bPreviewing Then
ClosePreviewWindow()
End If
MyBase.Finalize()
End Sub
Public ReadOnly Property DeviceList() As Collection
Get
Return mDevice
End Get
End Property
Public Sub New()
LoadDeviceList()
If mDevice.Count = 0 Then
Throw New Exception("No Video Capture Device Present.")
End If
End Sub
End Class
Public Class WebcamInfo
Private mstrDevice As String
Private mstrVersion As String
Public Property Device() As String
Get
Return mstrDevice
End Get
Set(ByVal Value As String)
mstrDevice = Value
End Set
End Property
Public Property Version() As String
Get
Return mstrVersion
End Get
Set(ByVal Value As String)
mstrVersion = Value
End Set
End Property
End Class
Ken
---------------------------
"anonymous" <so*****@somedomain.com> wrote in message
news:%2****************@tk2msftngp13.phx.gbl...
hi all,
I'm trying to use the capCreateCaptureWindow (see
http://msdn.microsoft.com/library/de...turewindow.asp)
in a Windows Application Project. I want to pass Image as one of the
parameter but I figure that an Image doesn't have a handle. Previously I
had it working in a Web Application Project using the handle of a
PictureBox.
Is there any workaround? Please help and thank you very much.
