Question

VB timer控件

等待插卡，从9开始按1秒递减，当减到5时还没检测到卡片，就msgbox“没发现卡片” 只要在5之内，就MSGBOX “发现卡片” 识别卡片的函数st=chk_442(icdev) st=0 识别成功

Answer 1

private sub command1_click() '按下等待插卡按钮
Timer1.Interval = 1000
Timer1.Enabled = True
Call Timer1_Timer
end sub

private sub Timer1_Timer() '读秒
static n as integer
Dim st
if n=0 then n=9
n=n-1
Label1.Caption=n
st=chk_442(icdev)
if n<5 or st=0 then
msgbox “发现卡片”
n=9
Timer1.Enabled = False
Else
if n=5 then
msgbox “没发现卡片”
n=9
Timer1.Enabled = False
end if
end if
end sub

Answer 2

dim t as integer
Private Sub Form1_Load()
t=9
Time1.Interval=1000 '即每隔1000毫秒（1秒）触发一次。
Time1.Enable=True 'Time1使能，开始计时
End Sub
Private Sub Timer1_Timer()
Dim st as Integer
t=t-1
st=chk_442(icdev)
if st=0 then '识别成功
Time1.Enable=False 'Time1停止计时
MSGBOX “发现卡片”
else
if t=5 then
Time1.Enable=False 'Time1停止计时
msgbox “没发现卡片"
end if
end if

End Sub