用vb.net實(shí)現(xiàn)網(wǎng)絡(luò)通信

用 vb.net socket通信

創(chuàng)新互聯(lián)公司是一家專注于成都網(wǎng)站制作、網(wǎng)站建設(shè)、外貿(mào)網(wǎng)站建設(shè)與策劃設(shè)計,堆龍德慶網(wǎng)站建設(shè)哪家好?創(chuàng)新互聯(lián)公司做網(wǎng)站,專注于網(wǎng)站建設(shè)10多年,網(wǎng)設(shè)計領(lǐng)域的專業(yè)建站公司;建站業(yè)務(wù)涵蓋:堆龍德慶等地區(qū)。堆龍德慶做網(wǎng)站價格咨詢:028-86922220

Dim th As Threading.Thread

2 Dim tcpl As System.Net.Sockets.TcpListener

3

4 Private Sub Form1_Load()Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

5 th = New System.Threading.Thread(New System.Threading.ThreadStart(AddressOf MyListen))

6 th.Start()

7 End Sub

8

9 Public Sub SendMessage()Sub SendMessage(ByVal IP As String, ByVal SendMsg As String)

10 Try

11 If IP "" Then

12 Dim tcpc As New System.Net.Sockets.TcpClient(IP, 5656)

13 Dim tcpStream As Net.Sockets.NetworkStream = tcpc.GetStream

14 Dim reqStream As New IO.StreamWriter(tcpStream)

15 reqStream.Write(SendMsg)

16 reqStream.Flush()

17 tcpStream.Close()

18 tcpc.Close()

19 End If

20 Catch ex As Exception

21 MsgBox(ex.Message.ToString)

22 End Try

23 End Sub

24 Private Sub MyListen()Sub MyListen()

25 Try

26 Dim ipAddress As System.Net.IPAddress = System.Net.Dns.Resolve(System.Net.Dns.GetHostName).AddressList(0)

27 tcpl = New System.Net.Sockets.TcpListener(ipAddress, 5656)

28 tcpl.Start()

29 While True

30 Dim s As System.Net.Sockets.Socket = tcpl.AcceptSocket()

31 Dim MyBuffer(1024) As Byte

32 Dim i As Integer

33 i = s.Receive(MyBuffer)

34 If i 0 Then

35 Dim lstrRec As String

36 Dim j As Integer

37 For j = 0 To i - 1

38 TextBox1.Text += Chr(MyBuffer(j)) ","

39 Next

40 End If

41 End While

42 Catch ex As Exception

43 MsgBox(ex.Message.ToString)

44 End Try

45 End Sub

46

47 Private Sub Button1_Click()Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

48 SendMessage("192.168.0.61", TextBox2.Text)

49 End Sub

VB.NET如何判斷電腦是否已連接到網(wǎng)絡(luò)？

Microsoft.VisualBasic.Devices.Network.IsAvailable As Boolean

生成實(shí)例后可以通過此屬性來獲取是否聯(lián)網(wǎng)的值，True代表已聯(lián)網(wǎng)，F(xiàn)alse代表沒有聯(lián)網(wǎng)

Microsoft.VisualBasic.Devices.Network.NetworkAvailabilityChanged(ByVal Object, ByVal Microsoft.VisualBasic.Devices.NetworkAvailableEventArgs)

該事件是在電腦斷開/連上互聯(lián)網(wǎng)是引發(fā)的

其中：

e.IsNetworkAvailable

的功能同Microsoft.VisualBasic.Devices.Network.IsAvailable

實(shí)例:

Dim?netListener?As?New?Microsoft.VisualBasic.Devices.Network?'生成實(shí)例

If?netListener.IsAvailable?=?True?Then

MsgBox("已聯(lián)網(wǎng)")

Else

MsgBox("未聯(lián)網(wǎng)")

End?If

NetworkAvailabilityChanged實(shí)例：

WithEvents?netListener?As?New?Microsoft.VisualBasic.Devices.Network?'生成實(shí)例

Private?Sub?OnNetworkChanged(ByVal?Object,?ByVal?Microsoft.VisualBasic.Devices.NetworkAvailableEventArgs)Handles?netListener.NetworkAvailabilityChanged

If?e.IsNetworkAvailable?=?True?Then

MsgBox("已聯(lián)網(wǎng)")

Else

MsgBox("未聯(lián)網(wǎng)")

End?If

End?Sub

vb.net中如何判斷網(wǎng)絡(luò)連接？

新建模塊

Function IsHearOK(ByVal URL As String) As Boolean '判斷網(wǎng)頁是否存在函數(shù)

Dim XMLObject As Object, ReturnType As String

XMLObject = CreateObject("Microsoft.XMLHTTP")

XMLObject.Open("GET", URL, False)

XMLObject.setRequestHeader("CONTENT-TYPE", "application/x-www-form-urlencoded")

XMLObject.setRequestHeader("Range", "bytes=1-255")

Try

XMLObject.Send()

If XMLObject.Status = 200 Or XMLObject.Status = 206 Then

ReturnType = XMLObject.getResponseHeader("CONTENT-TYPE")

If UCase(ReturnType) "TEXT/HTML" Then

IsHearOK = True

Else

IsHearOK = False

End If

Else

IsHearOK = False

End If

Catch

MsgBox("連接異常，請檢查網(wǎng)絡(luò)！", , "提醒")

XMLObject = Nothing

End Try

End Function

調(diào)用 ishearok（url）=true 正常

vb.net 檢測網(wǎng)絡(luò)連接

既然從網(wǎng)上找的實(shí)例沒問題，也許就是調(diào)用的時候沒出來或者在檢測網(wǎng)卡當(dāng)中出現(xiàn)了問題。