UDP application for VB.NET

ahai163
3.51/5 (31 votes)
Sep 3, 2003
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The Sample help u basic understand how to develop UDP application under VB.NET
Download source files - 52 Kb
Introduction

AS my experience, the UDP protocol is convinent than TCP, especially your program is running Base LAN. it is enough reliable to comunicate and efficient. so I will provide one peer to peer comunicated application by UDP protocol.
Recent years, I have got a lot of benifits from codeproject Sites, So I also would like to
contribute my experince , share with u
I am from China, not be good at English.
The base class for UDP is presented as following:


#Region "info - English"
''' The Example will help u a fully understand UDP, Thread, and Encoding
''' Through the Example, U will see how to solve the Blocking problem about 
''' Receive function related UDP.
''' U can try it.
#End Region 
#Region "Imports"
Imports System
Imports System.IO
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports System.Threading
#End Region 

Public Class xSock 
#Region "Declares"
    Private Shared UDP_Client As New UdpClient
    Private Shared UDP_Server_Port As Integer
    Private Shared thdUdp As Thread
    Private Shared UDP_Server As UdpClient
#End Region 
#Region "Events"
    'Public Event Close()
    Public Shared Event DataArrival(ByVal Data As String)
    Public Shared Event Sock_Error(ByVal Description As String)
#End Region 

#Region "UDP" 
    Public Shared Sub UDP_Send(ByVal Host As String, ByVal Port As Integer,_
  ByVal Data As String)
        Try
            UDP_Client.Connect(Host, Port)
            Dim sendBytes As [Byte]() = Encoding.Unicode.GetBytes(Data)
            UDP_Client.Send(sendBytes, sendBytes.Length) 
        Catch e As Exception
            RaiseEvent Sock_Error(e.ToString)
        End Try 
    End Sub 
    Public Shared Function UDP_Listen(ByVal Port As Integer) As Boolean
        Try
            UDP_Server_Port = Port
            UDP_Server = New UdpClient(Port)
            thdUdp = New Thread(AddressOf GetUDPData)
            thdUdp.Start()
        Catch e As Exception
            RaiseEvent Sock_Error(e.ToString)
        End Try 
    End Function 
    Private Shared Sub GetUDPData()
        Do While True
            Try
                Dim RemoteIpEndPoint As New IPEndPoint(IPAddress.Any, 0)
                Dim RData = Encoding.Unicode.GetString(_
UDP_Server.Receive(RemoteIpEndPoint))
                RaiseEvent DataArrival(RData)
                If RData = "CloseMe" Then Exit Do
                Thread.Sleep(0)
            Catch e As Exception
                RaiseEvent Sock_Error(e.ToString)
            End Try
        Loop
    End Sub 
    Public Shared Sub CloseSock()
        UDP_Send("127.0.0.1", UDP_Server_Port, "CloseMe")
        Thread.Sleep(30)
        UDP_Server.Close()
        thdUdp.Abort()
    End Sub
#End Region 
End Class

 The Server Exampe: also has Client Function

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    '窗体重写 dispose 以清理组件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents cmdSend As System.Windows.Forms.Button
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.cmdSend = New System.Windows.Forms.Button
        Me.TextBox2 = New System.Windows.Forms.TextBox
        Me.SuspendLayout()
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(32, 32)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(256, 20)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = "TextBox1"
        '
        'cmdSend
        '
        Me.cmdSend.Location = New System.Drawing.Point(168, 64)
        Me.cmdSend.Name = "cmdSend"
        Me.cmdSend.Size = New System.Drawing.Size(128, 24)
        Me.cmdSend.TabIndex = 1
        Me.cmdSend.Text = "Send"
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(32, 160)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(264, 20)
        Me.TextBox2.TabIndex = 2
        Me.TextBox2.Text = "TextBox2"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(328, 317)
        Me.Controls.Add(Me.TextBox2)
        Me.Controls.Add(Me.cmdSend)
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        xSock.UDP_Listen(10090)
        AddHandler xSock.DataArrival, AddressOf OnDataRival
    End Sub

    Private Sub cmdSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdSend.Click
        xSock.UDP_Send("127.0.0.1", 10080, TextBox1.Text)
    End Sub

    Private Sub OnDataRival(ByVal vMsg As String)
        TextBox2.Text = vMsg
    End Sub
    Private Sub Form1_Closing(ByVal sender As Object, _
 ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
        xSock.CloseSock()
    End Sub
End Class


Client Example, also has Server Function

Imports System.Threading
Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    '窗体重写 dispose 以清理组件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> _
      Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.SuspendLayout()
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(24, 88)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(272, 20)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = "TextBox1"
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(176, 160)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(120, 24)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "Close Listen"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(176, 208)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(120, 24)
        Me.Button2.TabIndex = 2
        Me.Button2.Text = "Start Listen"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(328, 309)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

 


    Private Sub Form1_Load(ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles MyBase.Load
        xSock.UDP_Listen(10080)
        AddHandler xSock.DataArrival, AddressOf UDPArrival
    End Sub
    Private Sub UDPArrival(ByVal vData As String)
        TextBox1.Text = vData
        xSock.UDP_Send("127.0.0.1", 10090, vData)
    End Sub

    Private Sub Form1_Closing(ByVal sender As Object, _
  ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
        xSock.CloseSock()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, _
           ByVal e As System.EventArgs) Handles Button1.Click
        xSock.CloseSock()
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, _
         ByVal e As System.EventArgs) Handles Button2.Click
        xSock.UDP_Listen(10080)
    End Sub
End Class
Thanks. if u have any comment that.