101/03/16

程式設計工藝大師

簡而言之，TCP 提供的是一個可靠的資料流傳送服務：相對而言，UDP 提供的是一個非可靠的非連線型(connectionless)的資料流傳送服務。 http://www.study-area.org/network/network_ip_tcp.htm

sever  與client 端執行畫面

 sever端等待

sever程式碼

Option Explicit

Private Sub cmdSend_Click()

  Winsock1.SendData txtSend.Text

End Sub

Private Sub Form_Load()

  Winsock1.LocalPort = 7777

  Winsock1.Listen  '監聽

  End Sub

Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)

  Dim strData As String

  Winsock1.GetData strData, vbString

  txtReceived.Text = strData

  If strData = "close" Then

    Winsock1.Close

    cmdSend.Enabled = False

    Winsock1.Listen

  End If

End Sub

Private Sub Winsock1_ConnectionRequest(ByVal requestID As Long)

  MsgBox "有人敲門"   '當對方連線到我的主機會顯示有人敲門

  Winsock1.Close

  Winsock1.Accept requestID  '改成接受

  cmdSend.Enabled = True

End Sub

client 程式碼

Private Sub cmdConnect_Click()

  Winsock1.LocalPort = 0   '以便自動產生Local Port

  Winsock1.Connect "192.168.15.47"  '設定改成您 Server 電腦的IP 號碼

End Sub

Private Sub cmdExit_Click()

  Winsock1.SendData "close"

  DoEvents

  Winsock1.Close

  Winsock1.LocalPort = 0

End Sub

Private Sub cmdSend_Click()

  Winsock1.SendData txtOutput.Text

  DoEvents

End Sub

Private Sub Form_Load()

  Winsock1.RemotePort = 7777  '設定與Server端做Listen的Port相同

End Sub

Private Sub Form_Unload(Cancel As Integer)

If Winsock1.State <> sckClosed Then

   cmdExit_Click

End If

End Sub

Private Sub Winsock1_Connect()

If Winsock1.State = sckConnected Then

   lstInput.AddItem "Connected! LocalPort =" & Winsock1.LocalPort _

                    & " RemptePort = " & Winsock1.RemotePort

End If

End Sub

Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)

  Dim mydata As String

  Winsock1.GetData mydata, vbString

  lstInput.AddItem mydata

End Sub

Private Sub Winsock1_Error(ByVal Number As Integer, Description As String, ByVal Scode As Long, ByVal Source As String, ByVal HelpFile As String, ByVal HelpContext As Long, CancelDisplay As Boolean)

  lstInput.AddItem Description

End Sub