Question

如何检查我是否有开放的网络连接，并且可以联系c＃中的特定IP地址？我在VB.Net中看到了一些例子，但它们都使用了'My'结构。谢谢。

Answer 1

如果您只是想检查网络是否已启动，请使用：

bool networkUp
    = System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable();

要检查特定接口的状态（或其他信息），请使用：

NetworkInterface[] networkCards
    = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces();

要检查远程计算机的状态，您必须连接到该计算机（请参阅其他答案）

Answer 2

如果您想监控状态的变化，请使用System.Net.NetworkInformation.NetworkChange.NetworkAvailabilityChanged事件：

NetworkChange.NetworkAvailabilityChanged 
    += new NetworkAvailabilityChangedEventHandler(NetworkChange_NetworkAvailabilityChanged);
_isNetworkOnline = NetworkInterface.GetIsNetworkAvailable();


// ...
void NetworkChange_NetworkAvailabilityChanged(object sender, NetworkAvailabilityEventArgs e)
{
    _isNetworkOnline  = e.IsAvailable;
}

Answer 3

第一个建议（IP连接）

您可以尝试使用以下内容连接到IP地址：

IPEndPoint ipep = new IPEndPoint(Ipaddress.Parse("IP TO CHECK"), YOUR_PORT_INTEGER);
Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
server.Connect(ipep);

我建议你查看“聊天”程序的代码。这些程序操纵了大量的IP连接，可以让您了解如何检查IP是否可用。

第二个建议（Ping）

您可以尝试ping。这是一个很好的tutorial。你只需要这样做：

Ping netMon = new Ping();
PingResponse response = netMon.PingHost(hostname, 4);
if (response != null)
{
    ProcessResponse(response);
}

Answer 4

如果您对HTTP状态代码感兴趣，以下工作正常：

using System;
using System.Net;

class Program {

    static void Main () {
        HttpWebRequest req = WebRequest.Create(
            "http://www.oberon.ch/") as HttpWebRequest;
        HttpWebResponse rsp;
        try {
            rsp = req.GetResponse() as HttpWebResponse;
        } catch (WebException e) {
            if (e.Response is HttpWebResponse) {
                rsp = e.Response as HttpWebResponse;
            } else {
                rsp = null;
            }
        }
        if (rsp != null) {
            Console.WriteLine(rsp.StatusCode);
        }
    }

}

此致 tamberg

Answer 5

好吧，你会尝试连接到特定的ip，并处理拒绝和超时。

查看System.Net.Sockets命名空间中的TcpClient类。

Answer 6

我的想法是让一个静态类/模块在一个spereate线程上进行监控。简单的DNS解析将确保您的网络正常运行。 Beats ping IMO。

Imports System.Net

Public Module Network_Monitor

Private InsideWorkNet As Boolean = vbFalse
Private Online_Status As Boolean = vbFalse
Private CurrentWorkIPAddress As New IPHostEntry
Private WithEvents Timer_Online_Check As New Timers.Timer With {.Interval = 5000, .Enabled = True, .AutoReset = True}


Public ReadOnly Property GetOnlineStatus() As String

    Get
        Return Online_Status
    End Get

End Property


Public Sub Initialize()

    Set_Online_Status()
    Timer_Online_Check.Start()

End Sub


Public Sub Set_Online_Status()

    If My.Computer.Network.IsAvailable Then
        Try
            Dim DNSTest As IPHostEntry = Dns.GetHostEntry("google.com")
            If DNSTest.AddressList.Length > 0 Then
                Online_Status = True
            Else : Online_Status = False

            End If

        Catch ex As System.Net.Sockets.SocketException

            Online_Status = False

        End Try
    End If

End Sub


Private Sub Timer_Online_Check_Elaspsed(ByVal sender As Object, ByVal e As Timers.ElapsedEventArgs) Handles Timer_Online_Check.Elapsed
    Set_Online_Status()
End Sub

Public Sub Detect_Work_Network()

    If Online_Status = True Then

        Dim WorkIP As IPHostEntry = New IPHostEntry()

        Try
            WorkIP = Dns.GetHostEntry("serverA.myworkdomain.local")
            If WorkIP.AddressList.Length > 0 Then

                InsideWorkNet = True
                CurrentWorkIPAddress = WorkIP
                'MessageBox.Show(WorkIP.HostName.ToString(), "WorkIP", MessageBoxButtons.OK, MessageBoxIcon.Information)
            End If
        Catch ex As Sockets.SocketException

            Try
                WorkIP = Dns.GetHostEntry("serverA.myworkdomain.com")
                If WorkIP.AddressList.Length > 0 Then

                    InsideWorkNet = False
                    CurrentWorkIPAddress = WorkIP
                    ' MessageBox.Show(WorkIP.HostName.ToString(), "WorkIP", MessageBoxButtons.OK, MessageBoxIcon.Information)
                End If
            Catch ey As Sockets.SocketException

            End Try
        End Try
    End If

End Sub

Public Function GetWorkServerName() As String
    If InsideWorkNet = True Then
        Return "serverA.myworkdomain.local"
    Else : Return "serverA.myworkdomain.com"
    End If


End Function



End Module

我还必须确定我是在工作网络的内部还是外部。防火墙两侧的不同服务器供应用程序通信。

Answer 7

您可以使用

检查网络状态

if(System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable())
{
  //Do your stuffs when network available

}
else
{
 //Do stuffs when network not available

}

在C＃中检查网络状态

7 个答案:

第一个建议（IP连接）

第二个建议（Ping）