Question

Private _clientTCPList As ArrayList = ArrayList.Synchronized(New ArrayList())

' get tcp client
  Dim clientTCP As TcpClient = serverTCP.EndAcceptTcpClient(ar)

' get new ip address from tcp client
   Dim  newClientIPAddress as IPAddress = TryCast(clientTCP.Client.RemoteEndPoint, IPEndPoint).Address

' find new ip-address in tcp-client array list, if ip-address isn't found then add new  
  tcp-client to last index of aray list, but if founded then replace old tcp-client in array list with new tcp-client object.

  Dim i As Integer = 0
  Dim clientIPAddressFound As Boolean = False

  SyncLock _clientTCPList
      For Each t As TcpClient In _clientTCPList
          If t.Client IsNot Nothing Then
              Dim oldClientIPAddress As IPAddress = TryCast(t.Client.RemoteEndPoint, IPEndPoint).Address
              If oldClientIPAddress IsNot Nothing Then
                  If Object.Equals(oldClientIPAddress, newClientIPAddress) Then
                      clientIPAddressFound = True
                      Exit For
                   End If
              End If
          End If
          i += 1
       Next
  End SyncLock

‘ If the more then 1000 client connected to a server,looping to find the objects(ip address) inside array list(tcp clients), takes a long time. Is there a quick methode to replace the manual search of work. Thanks

Answer 1

You can create a HashSet of IP addresses, and keep client IP addresses there. Lookup in hash set does not require a loop: you simply use its Contains(...) method.