2012-3-15

http://tccnchsu.blogspot.com/ 程式設計工藝大師


TCP(Transmission Control Protocol)
UDP(User Datagram Protocol)

TCP這個協定最主要的特色在於傳輸資料時，需要驗證資
料，確保正確性。所以花的時間稍多一點。

而UDP這個協定最主要的特色在於傳輸資料時，不需要驗
證資料，不保證正確性，所以比較省時間。而一般來說，
像是多媒體串流(streaming)就是使用這種協定。
參考文獻:http://hazuki016.pixnet.net/blog/post/13288265-tcp%E8%88%87udp%E7%9A%84%E6%AF%94%E8%BC%83

參考文獻:http://blog.yam.com/ibma92157/article/27580746 

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當SVERVER端連線到我的CLIENT端

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"

  Winsock1.Close

  Winsock1.Accept requestID  '改成接受

  cmdSend.Enabled = True

End Sub

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我SVERVER端連線到別CLIENT端 

Private Sub cmdConnect_Click()

  Winsock1.LocalPort = 7777   '以便自動產生Local Port

  Winsock1.Connect "192.168.15.32 "  '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