[SOLVED] How can I detect if there is a webcam connected to the PC?

How can I detect if there is a webcam connected to the PC?

I have the source code for taking a picture via webcam, but I need to know if there's a webcam connected to the PC. If there's no webcam, the program won't call the function for taking photos. If necessary, I need to know which window's Api I have to use in this case.

Language: Visual Basic 6 using windows Apis.

Solution

The problem with the WIA is that not all devices are compatible. But I found the solution myself: SendMessage and capCreateCaptureWindowA work together. If there's no camera, SendMessage returns a "0". This is the code:

imports:

'This code is in Module1.bas
Option Explicit
Public Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long

Public 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

Public Const WM_USER = 1024
Public Const WM_CAPCONNECT As Long = 1034
Public Const DISCONNECT As Long = 1035
Public Const WM_CAP_SET_PREVIEW = WM_USER + 50
Public mCapHwnd As Long

Code:

mCapHwnd = capCreateCaptureWindowA("WebCap", 0, 0, 0, m_Width, m_Height, Me.hwnd, 0)
DoEvents
If SendMessage(mCapHwnd, WM_CAP_CONNECT, 0, 0) <> 0 Then
Call SendMessage(mCapHwnd, WM_CAP_CONNECT, 0, 0)
DoEvents
Call SendMessage(mCapHwnd, WM_CAP_SET_PREVIEW, 0, 0)
Else
MsgBox "No Camera Detected"
End If

I hope somebody can find this useful :)