VB6+API Win7 下摄像头不稳定，高手进
在XP下运行完全正常。在Win7下，有时完全正常，有时启动程序会出现win7自带的设备选择提示。无论是点确定还是取消，均无法获取图像。请高手分析。
代码如下：
'============================================================================================
'声明部分
'============================================================================================
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 Preview_Handle As Long
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 Function CapturePicture(nCaptureHandle As Long) As StdPicture
Clipboard.Clear
SendMessage nCaptureHandle, WM_CAP_EDIT_COPY, 0, 0
Set CapturePicture = Clipboard.GetData
End Function
'============================================================================================
'程序加载时将摄像头内容传送到Picture1上。 640 480代表分辨率
'============================================================================================
Private Sub Form_Load()
Preview_Handle = capCreateCaptureWindow("Video", WS_CHILD + WS_VISIBLE, 0, 0, 640, 480, Picture1.hwnd, 1)
SendMessage Preview_Handle, WM_CAP_DRIVER_CONNECT, 0, 0
SendMessage Preview_Handle, WM_CAP_SET_PREVIEWRATE, 1, 0
SendMessage Preview_Handle, WM_CAP_SET_PREVIEW, 1, 0
End Sub
Private Sub Form_Unload(Cancel As Integer)
SendMessage Preview_Handle, WM_CAP_DRIVER_DISCONNECT, 0, 0
End Sub
[解决办法]
