資料出處程式設計工藝大師 


TCP 提供一個可靠的資料流傳送服務，UDP 則提供一個非可靠的非連線型的資料流傳送服務。
TCP
優點:傳送可靠
缺點:速度比較慢
UDP
優點:傳輸量大且迅速
缺點:不可靠，程式需自行提供可靠的機制 

Example

Server端

Option Explicit

Private Sub cmdSend_Click()

  Winsock1.SendData txtSend.Text

End Sub

Private Sub Form_Load()

  Winsock1.LocalPort = 7777  %LocalPort須與Cleint Winsock1.RemotePort相同

  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!!!!!"  %彈出"有人敲門!!!!!"的視窗

  Winsock1.Close

  Winsock1.Accept requestID  '改成接受

  cmdSend.Enabled = True

End Sub

Cleint端

Private Sub cmdConnect_Click()

  Winsock1.LocalPort = 6666   '以便自動產生Local Port

  Winsock1.Connect "192.168.15.54"  '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

socket基本概念