检查网络可用性VB.net

Question

我正在编写一个应用程序，该应用程序将在网络连接将定期打开/关闭的移动环境中使用。如何检查特定网络是否可用？

Answer 1

试试NetworkInterface.GetIsNetworkAvailable

表示是否有可用的网络连接。

如果任何网络接口被标记为"up“并且不是环回或隧道接口，则认为网络连接可用。

Answer 2

要查看是否有可用的网络，可以使用VB.NET My名称空间：

My.Computer.Network.IsAvailable

我猜这是Andrew答案中NetworkInterface属性的抽象。要查看是否可以使用可用的网络访问特定的服务器，可以使用

My.Computer.Network.Ping(host name or IP address, or a System.Uri)

Answer 3

我喜欢挖掘旧的线索！我的解决方案是使用DNS进行测试。这样，您可以在xxx网络内测试特定的名称，以判断您是在内部还是外部。嵌套的try语句说明了这一概念。

Imports System.Net

Module Networker

Dim Online_Status As Boolean = vbFalse
Dim InsideJoeNetwork As Boolean = vbFalse
Dim CurrentJoeIPAddress As New IPHostEntry



Public ReadOnly Property GetOnlineStatus() As String
    Get
        Return Online_Status
    End Get

End Property



Public ReadOnly Property InsideJoeNet() As String
    Get
        Return InsideJoeNetwork
    End Get

End Property



Sub Initialize()
    Set_Online_Status()

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
                Detect_Joe_Network()
            Else : Online_Status = False

            End If

        Catch ex As System.Net.Sockets.SocketException

            Online_Status = False

        End Try
    End If

End Sub



Public Sub Detect_Joe_Network()

    If Online_Status = True Then

        Dim JoeIP As IPHostEntry = New IPHostEntry()

        Try
            JoeIP = Dns.GetHostEntry("laptop")
            If JoeIP.AddressList.Length > 0 Then

                InsideJoeNetwork = True
                CurrentJoeIPAddress = JoeIP
                'MessageBox.Show(JoeIP.HostName.ToString(), "JoeIP", MessageBoxButtons.OK, MessageBoxIcon.Information)
            End If
        Catch ex As Sockets.SocketException

            Try
                JoeIP = Dns.GetHostEntry("laptop.exampledomain.com")
                If JoeIP.AddressList.Length > 0 Then

                    InsideJoeNetwork = False
                    CurrentJoeIPAddress = JoeIP
                    ' MessageBox.Show(JoeIP.HostName.ToString(), "JoeIP", MessageBoxButtons.OK, MessageBoxIcon.Information)
                End If
            Catch ey As Sockets.SocketException

            End Try
        End Try
    End If

End Sub

End Module