VB程序员博客
我拼凑了一个摄像头照相代码，但照相并给IMAGE1（在“员工信息”窗体中）赋值后，用DISCONNECT 截断与摄像头的联接后，原摄像头处显示黑屏，怎么也去不掉，因为在其他窗体中，不能用UNLOAD ME ，怎么办？
以下为模块：
Private Declare Function capCreateCaptureWindow Lib "avicap32.dll" _
Alias "capCreateCaptureWindowA" ( _
ByVal lpszWindowName As String, _
ByVal dwStyle As Long, _
ByVal x As Long, _
ByVal y As Long, _
ByVal nWidth As Long, _
ByVal nHeight As Long, _
ByVal hWndParent As Long, _
ByVal nID As Long) As Long
Private Const WS_CHILD = &H40000000
Private Const WS_VISIBLE = &H10000000
Private Const WM_USER = &H400
Private Const WM_CAP_START = &H400
Private Const WM_CAP_EDIT_COPY = (WM_CAP_START + 30)
Private Const WM_CAP_DRIVER_CONNECT = (WM_CAP_START + 10)
Private Const WM_CAP_SET_PREVIEWRATE = (WM_CAP_START + 52)
Private Const WM_CAP_SET_OVERLAY = (WM_CAP_START + 51)
Private Const WM_CAP_SET_PREVIEW = (WM_CAP_START + 50)
Private Const WM_CAP_DRIVER_DISCONNECT = (WM_CAP_START + 11)
Private Declare Function SendMessage Lib "user32" _
Alias "SendMessageA" ( _
ByVal hwnd As Long, _
ByVal wMsg As Long, _
ByVal wParam As Long, _
lParam As Any) As Long
Private Preview_Handle As Long
Public Function CreateCaptureWindow( _
hWndParent As Long, _
Optional x As Long = 750, _
Optional y As Long = 120, _
Optional nWidth As Long = 320, _
Optional nHeight As Long = 240, _
Optional ncameraid As Long = 0) As Long
Preview_Handle = capCreateCaptureWindow("Video", _
WS_CHILD + WS_VISIBLE, x, y, _
nWidth, nHeight, hWndParent, 1)
SendMessage Preview_Handle, WM_CAP_DRIVER_CONNECT, ncameraid, 0
SendMessage Preview_Handle, WM_CAP_SET_PREVIEWRATE, 30, 0
SendMessage Preview_Handle, WM_CAP_SET_OVERLAY, 1, 0
SendMessage Preview_Handle, WM_CAP_SET_PREVIEW, 1, 0
CreateCaptureWindow = Preview_Handle
End Function
Public Function CapturePicture(ncapturehandle As Long) As StdPicture
Clipboard.Clear
SendMessage ncapturehandle, WM_CAP_EDIT_COPY, 0, 0
Set CapturePicture = Clipboard.GetData
End Function
Public Sub Disconnect(ncapturehandle As Long, _
Optional ncameraid = 0)
SendMessage ncapturehandle, WM_CAP_DRIVER_DISCONNECT, _
ncameraid, 0
End Sub
以下为command1 command2 的命令代码，“员工信息”为IMAGE1所在的窗体名称
Private Sub command1_click()
On Error Resume Next
If Dir$("e:摄像头文件\kkk.jpg") = "" Then
MsgBox "请先采集照片！"
Command1.SetFocus
Else
Set Image1.Picture = LoadPicture("e:摄像头文件\kkk.jpg")
Kill "e:摄像头文件\kkk.jpg"
Command2.Enabled = True
Clipboard.Clear
Disconnect (Video_Handle)
Video_Handle = 0
End If
End Sub
Private Sub command2_click()
On Error Resume Next
Video_Handle = CreateCaptureWindow(员工信息.hwnd)
If Dir$("e:摄像头文件\kkk.jpg") = "" Then
Dim x As StdPicture
Set x = CapturePicture(Video_Handle)
SavePicture x, "e:摄像头文件\kkk.jpg"
Command2.Enabled = False
Else
Command1.SetFocus
End If
End Sub
command1 command2 的代码有一些修改，但仍不能解决问题，以下为修改后的代码：
Private Sub command1_click()
On Error Resume Next
Dim x As StdPicture
Set x = CapturePicture(Video_Handle)
Set Image1.Picture = x
Disconnect (Video_Handle)
Video_Handle = 0
Command2.Enabled = True
Command1.Enabled = False
Clipboard.Clear
End Sub
Private Sub command2_click()
On Error Resume Next
Video_Handle = CreateCaptureWindow(员工信息.hwnd)
Command2.Enabled = False
Command1.Enabled = True
End Sub
解决了，我新建了一个窗口，专门用来照相。