vb的30秒倒计时，要可以用vb打开的

Private Sub Command1_Click()
Timer1.Enabled = True
Command1.Enabled = False
End Sub

Private Sub Form_Load()
Command1.Caption = "倒计时开始"
Timer1.Interval = 1000
Timer1.Enabled = False
End Sub

Private Sub Timer1_Timer()
Static s
s = s + 1
t = 30 - s
Label1 = t
If t = 0 Then
Timer1.Enabled = False
Beep
End If
End Sub

建个timer
然后load的时候随时间-1就好了