推荐订阅源

Timer.bas：

Option ExplicitDeclare Function SetTimer Lib "user32" (ByVal hwnd As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long) As Long
Declare Function KillTimer Lib "user32" (ByVal hwnd As Long, ByVal nIDEvent As Long) As LongPublic Sub TimerProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal idEvent As Long, ByVal dwTime As Long)
    MsgBox Now()
End Sub

窗体代码：

Option ExplicitDim lngTimerID As Long
Dim BlnTimer As BooleanPrivate Sub Form_Load()
    BlnTimer = False
    Command1.Caption = "定时开始"
End SubPrivate Sub Form_Unload(Cancel As Integer)
    KillTimer 0, lngTimerID
End SubPrivate Sub Command1_Click()
    If BlnTimer = False Then
        '每5秒钟调用一次函数
        lngTimerID = SetTimer(0, 0, 5000, AddressOf TimerProc)
        BlnTimer = True
        Command1.Caption = "定时结束"
    Else
        KillTimer 0, lngTimerID
        BlnTimer = False
        Command1.Caption = "定时开始"
    End If
End Sub

说明：
TimerProc函数定义一定要放在bas模块文件中，否则运行代码"lngTimerID = SetTimer(0, 0, 5000, AddressOf TimerProc)"会报错，

提示：操作符 AddressOf 使用无效。