你可以在timer前用if判断网络状态，
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如断开，可用
threading.Thread.Sleep（10000） ‘当前线程挂起10秒
’可以开一个新线程去读取脱机数据。
如连接，则继续执行。
补充：
dim i as integer
'超过100次退出，避免死循环
for i=0 to 100
try
'ping你的端口
if ‘ok
exit for
else
threading.Thread.Sleep（10000） ‘当前线程挂起10秒
end
Catch ex As Exception
End Try
next
Sub Main() Dim thr As New Thread(AddressOf 循环) thr.Start("a") End Sub Sub 循环(a() As String) '这里随你干什么循环也行 For Each i As String In a MsgBox(i) Next End Sub
Sub Main()
Dim thr As Thread
For Pi As Integer=0 To 4 //启用5线程
MulParams =Pi vbTab sFile vbTab dFile vbTab 1 vbTab DelN vbTab cr vbTab cg vbTab cb vbTab IndexI
GlobalParamas(pi)=MulParams .Split(vbTab)
thr=New Thread(AddressOf MyMulThreadCaller)
thr.Start() //启动多线程进程
Application.DoEvents
Next
End Sub
多线程一般是不推荐用的，因为线程之间如果有共享资源的话会引起竞争，需要加锁处理；而且线程间没有时序关系，所以你在调试中可能会出现异步处理结束顺序与开始处理顺序不一致的情况（我在调试中已经发现该问题）。
针对你提出的这个问题，采用了多线程处理，利用的是BackgroundWorker也就是异步处理控件进行了处理。
代码已经经过调试通过。欢迎交流，如有问题，留下QQ或其他联系方式。
代码如下，并附程序截图。
‘---------------------------------------------------
Imports System.ComponentModel '导入异步控件命名空间
Public Class Form1
Private howmany As Integer = 10
Private AnalysisNumber(0 To howmany - 1) As BackgroundWorker
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
ListBox1.Items.Clear()
creatNewBackgroundWorker()
addHandle()
startWork()
End Sub
Private Sub creatNewBackgroundWorker()
For i As Integer = 0 To AnalysisNumber.Length - 1
AnalysisNumber(i) = New BackgroundWorker
Next
End Sub
Private Sub addHandle()
For i As Integer = 0 To AnalysisNumber.Length - 1
AddHandler AnalysisNumber(i).DoWork, AddressOf AnalysisNumber_DoWork
AddHandler AnalysisNumber(i).RunWorkerCompleted, AddressOf AnalysisNumber_RunWorkerCompleted
Next
End Sub
Private Sub startWork()
For i As Integer = 0 To 9
Dim temp(0 To 9) As Integer
For j As Integer = 1 To 10
temp(j - 1) = 10 * i + j
Next
AnalysisNumber(i).RunWorkerAsync(temp)
Next
End Sub
Private Sub AnalysisNumber_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs)
Dim data As Integer()
data = CType(e.Argument, Integer())
Dim temp As Integer
For i As Integer = 0 To data.Length - 1
temp = data(i)
data(i) = temp * temp
Next
e.Result = data
End Sub
Private Sub AnalysisNumber_RunWorkerCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs)
Dim data As Integer()
data = CType(e.Result, Integer())
For i As Integer = 0 To data.Length - 1
ListBox1.Items.Add(data(i))
Next
End Sub
End Class
