以下是引用apull在2020-8-11 17:17:05的发言：

用API

Private Declare Function GetForegroundWindow Lib "user32" () As Long

Private Sub Timer1_Timer()
    Dim wnd As Long
    Dim s As String
    wnd = GetForegroundWindow()
    s = "当前活动窗口句柄：" + Str(wnd) + "  Hex：" + Hex(wnd)
    Text1.Text = s
End Sub