基于VC/MFC 的UDP广播，我怎么接受返回的数据包

Posted 2023-05-05

创建UDP的socket server，端口就是返回的数据包使用的端口，然后在server的接收函数里面获取，删选；
或者也可以直接起个原始套接字的server，接收所有的套接字流，然后根据你的返回数据包的端口慢慢删选； 参考技术A 基于VC/MFC 的UDP广播有我在,没问题.

基于VC的MFC界面开发

教你熟悉VC6.0创建一个可视化软件的过程

UpdateData(TRUE);//将输入数据赋给文本框变量。
UpdateData(FALSE);//将内容显示在文本框中
AfxMessageBox("演示弹窗");

当使用弹窗的时候会阻塞进程。

使用VC++6.0开发一个弹窗程序

进阶（未实现）：VC++6.0可视化窗口怎么填加图片

本例是基于C语言实现的Windows socket的编程。

注意，在新建时不要勾选“Windows Socket”，因为用到了<winsock2.h>，勾选后会报错，说有一个结构体被定义了两次：

（这前面是你的VC安装路径）includewinsock2.h(99) : error C2011: 'fd_set' : 'struct' type redefinition

参考代码如下：

// 333Dlg.cpp : implementation file
//客户端

#include "stdafx.h"
#include "333.h"
#include "333Dlg.h"

#include <stdlib.h> 
#include<Winsock2.h>
#pragma comment (lib,"ws2_32.lib")
#define BUFFER_SIZE 1024 
#define MY_PORT 3434
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CMy333Dlg dialog

CMy333Dlg::CMy333Dlg(CWnd* pParent /*=NULL*/)
    : CDialog(CMy333Dlg::IDD, pParent)
{
    //{{AFX_DATA_INIT(CMy333Dlg)
    m = _T("");
    //}}AFX_DATA_INIT
    // Note that LoadIcon does not require a subsequent DestroyIcon in Win32
    m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMy333Dlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    //{{AFX_DATA_MAP(CMy333Dlg)
    DDX_Text(pDX, IDC_EDIT1, m);
    //}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CMy333Dlg, CDialog)
    //{{AFX_MSG_MAP(CMy333Dlg)
    ON_WM_PAINT()
    ON_WM_QUERYDRAGICON()
    ON_BN_CLICKED(IDC_BUTTON1, OnButton1)
    ON_EN_CHANGE(IDC_EDIT1, OnChangeEdit1)
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMy333Dlg message handlers

BOOL CMy333Dlg::OnInitDialog()
{
    CDialog::OnInitDialog();

    // Set the icon for this dialog.  The framework does this automatically
    //  when the application's main window is not a dialog
    SetIcon(m_hIcon, TRUE);         // Set big icon
    SetIcon(m_hIcon, FALSE);        // Set small icon
    
    // TODO: Add extra initialization here
    
    return TRUE;  // return TRUE  unless you set the focus to a control
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CMy333Dlg::OnPaint() 
{
    if (IsIconic())
    {
        CPaintDC dc(this); // device context for painting

        SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

        // Center icon in client rectangle
        int cxIcon = GetSystemMetrics(SM_CXICON);
        int cyIcon = GetSystemMetrics(SM_CYICON);
        CRect rect;
        GetClientRect(&rect);
        int x = (rect.Width() - cxIcon + 1) / 2;
        int y = (rect.Height() - cyIcon + 1) / 2;

        // Draw the icon
        dc.DrawIcon(x, y, m_hIcon);
    }
    else
    {
        CDialog::OnPaint();
    }
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CMy333Dlg::OnQueryDragIcon()
{
    return (HCURSOR) m_hIcon;
}

void CMy333Dlg::OnButton1() 
{
    // TODO: Add your control notification handler code here
        // TODO: Add your control notification handler code here
    SOCKET conn_sock;
    struct sockaddr_in client_addr;
    //WSA初始化
    WSADATA wsadata;
    WSAStartup(MAKEWORD(1,1),&wsadata);
    //配置connect
    conn_sock = socket(AF_INET,SOCK_STREAM,0);
    bind(conn_sock,(struct sockaddr*)&client_addr,sizeof(struct sockaddr));
    //配置server addr
    client_addr.sin_family = AF_INET;
    client_addr.sin_port = htons(MY_PORT);
    client_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    //链接
    connect(conn_sock,(struct sockaddr *)&client_addr,sizeof(struct sockaddr));
    //接收
    char rc[100] = "";
    recv(conn_sock,rc,sizeof(rc),0);
    //printf("From Server : %s
",rc);
    AfxMessageBox("连接成功！");
    //输入路径
    //printf("Please input path:
");
    //char path[100];
    //scanf("%s",&path);
    //发送路径
    //send(conn_sock,path,strlen(path),0);
    //打开文件，准备写入 
    FILE * fp = fopen(m, "rt"); 
    if(NULL == fp) 
    {    
        //printf("File: %s Can Not Open To Write
", path); 
        AfxMessageBox("打开文件失败！");
        system("pause"); 
        exit(1); 
    } 
    else
    { 
        char buffer[BUFFER_SIZE]; 
        memset(buffer, 0, BUFFER_SIZE);
        int length = 0;  
        //发送文件内容，直到读不到文件
        while((length = fread(buffer, sizeof(char), BUFFER_SIZE, fp)) > 0) 
        { 
            if (send(conn_sock, buffer, length, 0) < 0)//向服务端发送 
            { 
                //printf("Send File: %s Failed
", path); 
                AfxMessageBox("发送失败！");
                break; 
            } 
            memset(buffer, 0, BUFFER_SIZE); 
        } 
        //printf("File: %s Transfer Successful!
", path); 
        AfxMessageBox("发送成功！");
    }   
    fclose(fp); //关闭文件
    closesocket(conn_sock);
    WSACleanup();
}

void CMy333Dlg::OnChangeEdit1() 
{
    // TODO: If this is a RICHEDIT control, the control will not
    // send this notification unless you override the CDialog::OnInitDialog()
    // function and call CRichEditCtrl().SetEventMask()
    // with the ENM_CHANGE flag ORed into the mask.
    
    // TODO: Add your control notification handler code here
    UpdateData(TRUE);//将输入数据赋给文本框变量。
    UpdateData(FALSE);//将内容显示在文本框中
}

// 111Dlg.cpp : implementation file
//服务器端

#include "stdafx.h"
#include "111.h"
#include "111Dlg.h"
#include <Winsock2.h>
#pragma comment (lib,"ws2_32.lib")
#define BUFFER_SIZE 1024 
#define MY_PORT 3434
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif




/////////////////////////////////////////////////////////////////////////////
// CMy111Dlg dialog

CMy111Dlg::CMy111Dlg(CWnd* pParent /*=NULL*/)
    : CDialog(CMy111Dlg::IDD, pParent)
{
    //{{AFX_DATA_INIT(CMy111Dlg)
    m = _T("");
    //}}AFX_DATA_INIT
    // Note that LoadIcon does not require a subsequent DestroyIcon in Win32
    m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMy111Dlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    //{{AFX_DATA_MAP(CMy111Dlg)
    DDX_Text(pDX, IDC_EDIT1, m);
    //}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CMy111Dlg, CDialog)
    //{{AFX_MSG_MAP(CMy111Dlg)
    ON_WM_PAINT()
    ON_WM_QUERYDRAGICON()
    ON_BN_CLICKED(IDC_BUTTON1, OnStart)
    ON_EN_CHANGE(IDC_EDIT1, OnChangeEdit1)
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMy111Dlg message handlers

BOOL CMy111Dlg::OnInitDialog()
{
    CDialog::OnInitDialog();

    // Set the icon for this dialog.  The framework does this automatically
    //  when the application's main window is not a dialog
    SetIcon(m_hIcon, TRUE);         // Set big icon
    SetIcon(m_hIcon, FALSE);        // Set small icon
    
    // TODO: Add extra initialization here
    
    return TRUE;  // return TRUE  unless you set the focus to a control
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CMy111Dlg::OnPaint() 
{
    if (IsIconic())
    {
        CPaintDC dc(this); // device context for painting

        SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

        // Center icon in client rectangle
        int cxIcon = GetSystemMetrics(SM_CXICON);
        int cyIcon = GetSystemMetrics(SM_CYICON);
        CRect rect;
        GetClientRect(&rect);
        int x = (rect.Width() - cxIcon + 1) / 2;
        int y = (rect.Height() - cyIcon + 1) / 2;

        // Draw the icon
        dc.DrawIcon(x, y, m_hIcon);
    }
    else
    {
        CDialog::OnPaint();
    }
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CMy111Dlg::OnQueryDragIcon()
{
    return (HCURSOR) m_hIcon;
}

void CMy111Dlg::OnStart() 
{
    // TODO: Add your control notification handler code here
    //WSA初始化
    WSADATA wsadata;
    char *buffer = "Welcome ! Server connected.";//字符串
    struct sockaddr_in server_addr;
    SOCKET listen_socket;
    WSAStartup(MAKEWORD(1,1),&wsadata);
    

    //配置server addr

    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(MY_PORT);
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

    
    //配置listener
    listen_socket = socket(AF_INET,SOCK_STREAM,0);
    bind(listen_socket,(struct sockaddr*)&server_addr,sizeof(struct sockaddr));
    int flag = 1;
    while (flag)
    {
        //开始监听
        listen(listen_socket,5);
        int dummy = sizeof(SOCKADDR);
        //printf("Listening to client...
");
        AfxMessageBox("等待客户端连接......");
        //建立连接
        SOCKET new_socket = accept(listen_socket,NULL,&dummy);
        //printf("Client connected!
");
        AfxMessageBox("连接成功！准备从客户端接收文件......");
        //发送信息
        send(new_socket,buffer,strlen(buffer),0);
        char rc[100] = "";
        //recv(new_socket,rc,sizeof(rc),0);
        //printf("File name from Client : %s
",rc);
        //char path[100];
        char buf[999];
        //printf("Please set a path to save file:
");
        
        FILE * fp = fopen(m, "wt");//以写入的方式打开文件
        if (NULL == fp) 
        { 
            //printf("File: %s Not Found
", path); 
            AfxMessageBox("写入文件失败！");
        } 
        else
        { 
            memset(buf, 0, BUFFER_SIZE); 
            unsigned int length = 0; 
            //接受到客户端发来的文件数据
            while ((length = recv(new_socket, buf, BUFFER_SIZE, 0)) > 0) 
            { 
                //把发来的数据写入到文件中
                if (fwrite(buf, sizeof(char), length, fp) < length) 
                { 
                    //printf("File: %s Write Failed
", path); 
                    AfxMessageBox("接收失败！");
                    break; 
                } 
                memset(buf, 0, BUFFER_SIZE); 
            } 
            //printf("Receive File: %s From Server Successful!
", path); 
            AfxMessageBox("接收成功！");
            flag = 0;
        } 
        fclose(fp); //关闭文件
        closesocket(new_socket);
        
    }
    



    closesocket(listen_socket);
    WSACleanup();

}

void CMy111Dlg::OnChangeEdit1() 
{
    // TODO: If this is a RICHEDIT control, the control will not
    // send this notification unless you override the CDialog::OnInitDialog()
    // function and call CRichEditCtrl().SetEventMask()
    // with the ENM_CHANGE flag ORed into the mask.
    
    // TODO: Add your control notification handler code here
    UpdateData(TRUE);//将输入数据赋给文本框变量。
    UpdateData(FALSE);//将内容显示在文本框中
}