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obtain handle of Image

P: n/a
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.
Nov 20 '05 #1
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6 Replies


P: n/a
Cor
Hi anonymous,

If you tell a little bit more, what you want to do, then maybe we can give
you an answer in a more .Net approach with managed code?

Cor
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.

Nov 20 '05 #2

P: n/a
Hi Cor,

Thanks for replying. I am trying to capture video from a webcam.

Merry Christmas!

"Cor" <no*@non.com> bl news:%2****************@TK2MSFTNGP11.phx.gbl
g...
Hi anonymous,

If you tell a little bit more, what you want to do, then maybe we can give
you an answer in a more .Net approach with managed code?

Cor
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.


Nov 20 '05 #3

P: n/a
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.

Nov 20 '05 #4

P: n/a
* "anonymous" <so*****@somedomain.com> scripsit:
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.


The function expects a window handle, so passing the form's handle or a
picturebox's handle('Handle' property) should work.

--
Herfried K. Wagner [MVP]
<http://www.mvps.org/dotnet>
Nov 20 '05 #5

P: n/a
Cor
Anonymous,
Sorry not my stuf, I thought it where pictures, but maybe the others can
help you better now with this message
Merry Christmas

Cor

Thanks for replying. I am trying to capture video from a webcam.

Nov 20 '05 #6

P: n/a
Hi,

Here is a link to more video capture info.
http://www.shrinkwrapvb.com/videocap.htm

Ken
---------------------
"Ken Tucker [MVP]" <vb***@bellsouth.net> wrote in message
news:uq**************@TK2MSFTNGP10.phx.gbl...
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.


Nov 20 '05 #7

This discussion thread is closed

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