下面為傳送端

Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports System.Threading

Public Class Form_receive

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        '建立執行緒，執行 run 函式

        Dim t As Threading.Tasks.Task = Threading.Tasks.Task.Factory.StartNew(AddressOf run)
    End Sub


    Sub run()

        '更新 UI
        SetUI("執行緒開始", TextBox1)

        '   SetUI("執行緒結束", TextBox1)
        Dim U As New UdpClient(2017)
        Dim A As String
        Do While True

            Dim EP As New IPEndPoint(IPAddress.Any, 2017) '建立監聽端點資訊

            Dim B() As Byte = U.Receive(EP)

            A = Encoding.Default.GetString(B) '翻譯資訊為字串
            '更新 UI
            SetUI(A, TextBox1)
            Dim M As String = "Unknown Command"

            If A = "Time?" Then

                M = Now.ToString + "asd"

            End If

            B = Encoding.Default.GetBytes(M)

            U.Send(B, B.Length, EP) '回應詢問資料

        Loop
        ' raise一個事件出來說已經做完了
        ' 並將處理完的值回傳回去
    End Sub


    '設定 UI 

    Private Delegate Sub UpdateUI(ByVal msg As String, ByVal con As Control)

    Sub SetUI(ByVal str As String, ByVal con As Control)

        If Me.InvokeRequired() Then
            Dim um As New UpdateUI(AddressOf SetUI)
            Me.Invoke(um, str, con)
        Else
            TextBox1.Text = str
        End If

    End Sub


End Class