frmudp.frm

这个文件是有关系统串口通信的实例

VERSION 5.00
Object = "{248DD890-BB45-11CF-9ABC-0080C7E7B78D}#1.0#0"; "MSWINSCK.OCX"
Begin VB.Form Form1 
   Caption         =   "WinSock控件UDP"
   ClientHeight    =   6375
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   7680
   LinkTopic       =   "Form1"
   ScaleHeight     =   6375
   ScaleWidth      =   7680
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton cmdRemoteSet 
      Caption         =   "远程设置"
      Enabled         =   0   'False
      Height          =   375
      Left            =   6240
      TabIndex        =   15
      Top             =   2400
      Width           =   1095
   End
   Begin VB.Frame fraRemote 
      Caption         =   "本地机配置："
      Height          =   1455
      Left            =   5400
      TabIndex        =   12
      Top             =   3000
      Width           =   2055
      Begin VB.CommandButton cmdLocalSet 
         Caption         =   "本地配置"
         Height          =   375
         Left            =   840
         TabIndex        =   16
         Top             =   960
         Width           =   1095
      End
      Begin VB.TextBox txtLocalPort 
         Height          =   285
         Left            =   480
         TabIndex        =   13
         Top             =   495
         Width           =   1455
      End
      Begin VB.Label Label1 
         Caption         =   "输入本地端口："
         Height          =   255
         Left            =   120
         TabIndex        =   14
         Top             =   240
         Width           =   1335
      End
   End
   Begin VB.TextBox txtChat 
      Height          =   4335
      Left            =   120
      MultiLine       =   -1  'True
      ScrollBars      =   3  'Both
      TabIndex        =   10
      Top             =   480
      Width           =   5175
   End
   Begin VB.Frame fraInput 
      Caption         =   "交谈输入区："
      Height          =   1215
      Left            =   120
      TabIndex        =   5
      Top             =   4920
      Width           =   7215
      Begin VB.TextBox txtInput 
         Height          =   375
         Left            =   120
         TabIndex        =   8
         Top             =   600
         Width           =   5535
      End
      Begin VB.CommandButton cmdClear 
         Caption         =   "清空交谈内容"
         Height          =   375
         Left            =   5760
         TabIndex        =   7
         Top             =   120
         Width           =   1335
      End
      Begin VB.CommandButton cmdSend 
         Caption         =   "发送数据"
         Height          =   375
         Left            =   5760
         TabIndex        =   6
         Top             =   600
         Width           =   1335
      End
      Begin VB.Label Label8 
         Caption         =   "输入："
         Height          =   255
         Left            =   120
         TabIndex        =   9
         Top             =   360
         Width           =   615
      End
   End
   Begin VB.Frame fraLocal 
      Caption         =   "远程机配置："
      Height          =   2415
      Left            =   5400
      TabIndex        =   0
      Top             =   480
      Width           =   2055
      Begin VB.TextBox txtHost 
         Height          =   315
         Left            =   480
         TabIndex        =   2
         Top             =   680
         Width           =   1455
      End
      Begin VB.TextBox txtRemotePort 
         Height          =   285
         Left            =   480
         TabIndex        =   1
         Top             =   1340
         Width           =   1455
      End
      Begin VB.Label Label5 
         Caption         =   "输入主机名："
         Height          =   255
         Left            =   240
         TabIndex        =   4
         Top             =   400
         Width           =   1215
      End
      Begin VB.Label Label6 
         Caption         =   "输入远程端口："
         Height          =   255
         Left            =   240
         TabIndex        =   3
         Top             =   1080
         Width           =   1335
      End
   End
   Begin MSWinsockLib.Winsock WinsockUdp 
      Left            =   7080
      Top             =   0
      _ExtentX        =   741
      _ExtentY        =   741
      _Version        =   393216
   End
   Begin VB.Label Label9 
      Caption         =   "交谈显示窗口："
      Height          =   255
      Left            =   120
      TabIndex        =   11
      Top             =   240
      Width           =   1455
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Dim HostName As String * 256    '远程计算机名称
Dim LHostName As String * 256   '本机主机名称
Dim rPort As Long               '远程端口
Dim lPort As Long               '本地端口

Private Sub cmdClear_Click()
    txtChat.Text = vbNullString
End Sub

Private Sub cmdLocalSet_Click()
    If Trim$(txtLocalPort.Text) <> vbNullString Then
        lPort = CLng(Trim$(txtLocalPort.Text))
        '设置本地端口，同时开启远程设置功能
        WinsockUdp.localPort = lPort
        cmdRemoteSet.Enabled = True
    Else
        MsgBox "每个设置项不能为空！"
    End If
End Sub

Private Sub cmdSend_Click()
    Dim sData As String
    sData = Trim$(LHostName) & ":" & Trim$(txtInput.Text)
    On Error GoTo err:
    WinsockUdp.SendData sData
    
    'UDP传送数据并不能确保数据的正确送到，在此将自己的每次输入
    '都显示在交谈窗口
    txtChat.Text = Trim$(txtChat.Text) & sData & vbCrLf
    Exit Sub
err:
    MsgBox err.Description
End Sub

Private Sub cmdRemoteSet_Click()
    If Trim$(txtHost.Text) <> vbNullString Or _
        Trim$(txtRemotePort.Text) <> vbNullString Then
     
        rPort = CLng(Trim$(txtRemotePort.Text))
        HostName = Trim$(txtHost.Text)
        
        '设置远程端口和远程主机名
        WinsockUdp.RemotePort = rPort
        WinsockUdp.RemoteHost = Trim$(HostName)
        '绑定本地端口
        WinsockUdp.Bind lPort
    Else
        MsgBox "每个设置项不能为空！"
    End If
End Sub

Private Sub Form_Load()
    '设置好为UDP协议
    WinsockUdp.Protocol = sckUDPProtocol
    LHostName = WinsockUdp.LocalHostName
End Sub

Private Sub WinsockUdp_DataArrival(ByVal bytesTotal As Long)
    Dim sData As String
    On Error Resume Next
    WinsockUdp.GetData sData
    
    '如果传送的数据不是空字符，那么就显示在交谈窗口
    If Trim$(sData) <> vbNullString Then
        txtChat.Text = Trim$(txtChat.Text) & sData & vbCrLf
    End If
End Sub