摄像头拍照功能在vb6.0里怎样实现?
时间: 2024-06-10 13:10:38 浏览: 10
在VB6.0中实现摄像头拍照功能,需要使用Windows API函数来控制摄像头的操作。以下是一个简单的示例代码:
首先,在代码模块中声明以下API函数:
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 Declare Function capGetDriverDescriptionA Lib "avicap32.dll" (ByVal wDriver As Integer, ByVal lpszName As String, ByVal cbName As Long, ByVal lpszVer As String, ByVal cbVer As Long) As Boolean
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
Const WM_CAP_START = &H400S
Const WM_CAP_STOP = WM_CAP_START + 68
Const WM_CAP_SAVEDIB = WM_CAP_START + 25
Const WM_CAP_SET_PREVIEW = WM_CAP_START + 50
Const WM_CAP_SET_PREVIEWRATE = WM_CAP_START + 52
Const WM_CAP_SET_SCALE = WM_CAP_START + 53
Const WS_CHILD = &H40000000
Const WS_VISIBLE = &H10000000
接下来,在窗体的Load事件中添加以下代码:
Private Sub Form_Load()
Dim i As Integer
For i = 0 To 9
Dim Name As String * 100
Dim Version As String * 100
If capGetDriverDescriptionA(i, Name, 100, Version, 100) Then
Combo1.AddItem Left(Name, InStr(Name, Chr(0)) - 1)
End If
Next i
End Sub
这段代码会枚举当前系统中可用的摄像头,并将其名称添加到Combobox控件中。
然后,在拍照按钮的Click事件中添加以下代码:
Private Sub Command1_Click()
Dim hWnd As Long
Dim FileName As String
hWnd = capCreateCaptureWindow("Capture", WS_CHILD Or WS_VISIBLE, 0, 0, 640, 480, Me.hWnd, 0)
SendMessage hWnd, WM_CAP_SET_PREVIEWRATE, 66, 0
SendMessage hWnd, WM_CAP_SET_PREVIEW, True, 0
SendMessage hWnd, WM_CAP_SET_SCALE, True, 0
SendMessage hWnd, WM_CAP_START, 0, 0
FileName = App.Path & "\test.bmp"
SendMessage hWnd, WM_CAP_SAVEDIB, 0, ByVal FileName
SendMessage hWnd, WM_CAP_STOP, 0, 0
End Sub
这段代码会创建一个摄像头窗口,并将其设置为可见状态。然后,它会开始预览摄像头的图像,并将其保存为一个位图文件。最后,它会关闭摄像头窗口。
需要注意的是,这段代码只能使用一个摄像头。如果系统中有多个摄像头,需要根据实际情况修改代码。
另外,这段代码只能保存为位图文件。如果需要保存为其他格式,需要使用其他API函数来转换文件格式。