您好，这是我第一次在这里发帖。在这一点上，我已拼凑在一起 一个能够加载文本文件的应用程序，即时添加到一个＆＃34;列表框＆＃34;，现在我需要它来ping所有＆＃34;列表框＆＃34;但我得到一个错误，并停止工作。需要帮助ping所有ips。
Private Sub Go_Click(sender As Object, e As EventArgs) Handles Go.Click
If ListBox1.Items.Count <= 0 Then
MsgBox("Please Add at Least One IP or Website!")
Exit Sub
End If
For l_index As Integer = 0 To ListBox1.Items.Count - 1 'THIS IS WHERE CODE STOPS WORKING, NEED "MAGIC CODE" HERE
Dim lines As String = CStr(ListBox1.Items(l_index))
BackgroundWorker1.RunWorkerAsync(lines)
Next
End Sub
我正在使用Openfiledialog将文本文件加载到listbox1和backgroundworker来执行ping操作。我正在使用
Imports System.Net
Imports System.Net.NetworkInformation
Imports System.Threading
Imports System.IO
我想要做的就是所有＆＃34; IP＆＃34;在列表框中我想按Go去Ping所有Ips。我怎样才能让它发挥作用？
Imports System.Net
Imports System.Net.NetworkInformation
Imports System.Threading
Imports System.IO
Public Class Main
Private Sub AboutUpingToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles AboutUpingToolStripMenuItem.Click
AboutUping.Show()
End Sub
Private Sub MenuStrip1_ItemClicked(sender As Object, e As ToolStripItemClickedEventArgs) Handles MainMenu.ItemClicked
End Sub
Private Sub QuitToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles QuitToolStripMenuItem.Click
Application.Exit()
End Sub
Private Sub OpenFileDialog1_FileOk(sender As Object, e As System.ComponentModel.CancelEventArgs) Handles OpenFileDialog1.FileOk
Dim lines = File.ReadAllLines(OpenFileDialog1.FileName)
ListBox1.Items.AddRange(lines)
End Sub
Private Sub OpenToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles OpenToolStripMenuItem.Click
OpenFileDialog1.ShowDialog()
End Sub
Private Sub NewToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles NewToolStripMenuItem.Click
Create.Show()
End Sub
Private Sub ToolStripMenuItem1_Click(sender As Object, e As EventArgs) Handles ToolStripMenuItem1.Click
End Sub
Private Sub Main_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub Go_Click(sender As Object, e As EventArgs) Handles Go.Click
If ListBox1.Items.Count <= 0 Then
MsgBox("Please Add at Least One IP or Website!")
Exit Sub
End If
For l_index As Integer = 0 To ListBox1.Items.Count - 1 'THIS IS WHERE CODE STOPS WORKING, NEED "MAGIC CODE" HERE
Dim lines As String = CStr(ListBox1.Items(l_index))
BackgroundWorker1.RunWorkerAsync(lines)
Next
End Sub
Private Sub CloseFileToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles CloseFileToolStripMenuItem.Click
TextBox1.Clear()
ListBox1.Items.Clear()
End Sub
Private Sub cmdADD_Click(sender As Object, e As EventArgs) Handles cmdADD.Click
Dim myitem
myitem = txtADD.Text()
ListBox1.Items.Add(myitem)
txtADD.Clear()
End Sub
Private Sub cmdRemove_Click(sender As Object, e As EventArgs) Handles cmdRemove.Click
For a As Int32 = ListBox1.SelectedItems.Count - 1 To 0 Step -1
For i As Int32 = ListBox1.Items.Count - 1 To 0 Step -1
'-- compare the value of the select item to any given item in the list.
If ListBox1.SelectedItems(a) = ListBox1.Items(i) Then
'-- remove the item by the index we found
ListBox1.Items.RemoveAt(i)
'-- exit the inner for loop
Exit For
End If
Next
Next
End Sub
Private Sub cmdClear_Click(sender As Object, e As EventArgs) Handles cmdClear.Click
ListBox1.Items.Clear()
End Sub
Private Sub HelpToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles HelpToolStripMenuItem.Click
End Sub
Private Sub ListBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ListBox1.SelectedIndexChanged
End Sub
Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Dim lines = DirectCast(e.Argument, String())
Dim Ping As New Ping
Dim replies As New List(Of PingReply)
For Each ip In lines
Dim reply = Ping.Send(ip)
replies.Add(reply)
Next
e.Result = replies
End Sub
Private Sub BackgroundWorker1_RunWorkerCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
Dim sb As New System.Text.StringBuilder
Dim replies = DirectCast(e.Result, List(Of PingReply))
For Each reply In replies
Dim index As Integer
index += 1
sb.Append("Ping ").Append(index).Append(": ").Append(reply.Address).Append(" ").Append(reply.RoundtripTime).Append(" ms")
sb.AppendLine()
Next
TextBox1.Text = sb.ToString
End Sub
End Class
答案 0 :(得分：0)
您的错误在这里
你的一个ping失败并导致异常返回到已完成的事件处理程序，当处理程序尝试获取结果时抛出TargetInvocationException异常
解决方案是检查错误
Private Sub BackgroundWorker1_RunWorkerCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
If e.Error Is Nothing Then
Dim sb As New System.Text.StringBuilder
Dim replies = DirectCast(e.Result, List(Of PingReply))
For Each reply In replies
Dim index As Integer
index += 1
sb.Append("Ping ").Append(index).Append(": ").Append(reply.Address).Append(" ").Append(reply.RoundtripTime).Append(" ms")
sb.AppendLine()
Next
TextBox1.Text = sb.ToString
Else
'error handling
End If
End Sub
另外，您可能需要处理实际错误以保护其余的ping回复，否则因为1次失败将导致整批结果丢失
For Each ip As String In lines
Try
Dim reply As PingReply = Ping.Send(ip)
replies.Add(reply)
Catch ex as PingException
'error handling
End Try
Next
<强>更新
另一个错误点，
For l_index As Integer = 0 To ListBox1.Items.Count - 1
Dim lines As String = CStr(ListBox1.Items(l_index))
BackgroundWorker1.RunWorkerAsync(lines)
Next
因为你从上面的方法和下面的方法中作为单个字符串传递，你试图转换为字符串数组，所以它失败了，改变它就像这样
Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Dim ip = DirectCast(e.Argument, String)
Dim Ping As New Ping
Dim replies As New List(Of PingReply)
Try
Dim reply As PingReply = Ping.Send(ip)
replies.Add(reply)
Catch ex as PingException
'error handling
End Try
e.Result = replies
End Sub
还建议使用Option Strict On来减少某些类型检查错误
答案 1 :(得分：0)
谢谢！得到它的工作！发送＆＃34; Listbox1＆＃34;数组
Private Sub Go_Click(sender As Object, e As EventArgs) Handles Go.Click
Dim lines() As String = ListBox1.Items.OfType(Of String)().ToArray()
BackgroundWorker1.RunWorkerAsync(lines)
End Sub
现在它可以运行应用程序不会崩溃。