网络编程与多线程设计 VC6.0

时间：2010-05-13 来源：jxhaoxia

在使用WinSock MFC 类之前，必须为应用程序初始化WinSock 环境。

首先需要在StdAfx.h的MFC库头文件中，加入SOCKET的库
#include <afxsock.h>

然后在App()的InitInstance()中调用实例初始化函数AfxSocketInit()
if(!AfxSocketInit())
{
AfxMessageBox("Add Socket Failure");
return FALSE;
}

在Dlg()的OnInitDialog()中，调用函数InitSocket()初始化socket，创建线程

BOOL CDemopicDlg::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
    InitSocket();
//    AfxMessageBox("Test");
    //创建线程
    PARAM *pPARAM = new PARAM;
    pPARAM->sock = sock2fd;
    HANDLE hThread = CreateThread(NULL,0,RecvProc,(LPVOID)pPARAM,0,NULL);
    CloseHandle(hThread);    //关闭线程句柄

    iFrameLen = 113;
    cSend = (char *)malloc(iFrameLen);
    memset(cSend,0,iFrameLen);
    return TRUE; // return TRUE unless you set the focus to a control
}

//初始化两个SOCKET 1.作为客户端-发送数据，2.作为服务器-用于后台线程接收数据
BOOL CDemopicDlg::InitSocket()
{
    //------------------------------------------------------
    if((sockfd = socket(AF_INET,SOCK_DGRAM,0)) == -1)  //建立socket
    {
        AfxMessageBox("Socket Failed");
        closesocket(sockfd);
        return FALSE;
    }

    ServerAddress.sin_family = AF_INET;
    //ServerAddress.sin_addr.s_addr = inet_addr("10.11.6.111");
    ServerAddress.sin_addr.s_addr = inet_addr("10.11.6.33");
    ServerAddress.sin_port = htons(2233);
    //----------------------------------------------------

    if((sock2fd = socket(AF_INET,SOCK_DGRAM,0)) == -1) //建立socket
    {
        AfxMessageBox("Socket Failed");
        closesocket(sock2fd);
        return FALSE;
    }

    SOCKADDR_IN server_address;
    server_address.sin_family = AF_INET;
    server_address.sin_addr.s_addr = htonl(INADDR_ANY);
    server_address.sin_port = htons(3344);

    if(bind(sock2fd,(SOCKADDR*)&server_address, sizeof(server_address)) == -1)
    {
        AfxMessageBox("bind");
        closesocket(sock2fd);
        return FALSE;
    }
    //-----------------------------------------------------
    return TRUE;
}

子线程函数RecvProc()，作为后台函数接收UDP数据包，在recvfrom处阻塞

DWORD WINAPI CDemopicDlg::RecvProc(LPVOID lpParameter)
{
//AfxMessageBox("Test");//作为服务器
SOCKET sock2fd = ((PARAM*)lpParameter)->sock;

    int count = 0;
    int iFrameLen,iRecvLen;
    iFrameLen = 113;
    char *cRecv;
    cRecv = (char *)malloc(iFrameLen);
    memset(cRecv,0,iFrameLen);

    SOCKADDR_IN client_address;
    int client_len = sizeof(SOCKADDR);

    while(1)
    {
        iRecvLen = recvfrom(sock2fd,(char *)cRecv,iFrameLen,0,
            (SOCKADDR*)&client_address,&client_len);
        count++;
        if(iRecvLen == 0)
        {
            CString ttt;
            ttt.Format("%d",count);
            AfxMessageBox("后台线程接收到 "+ttt+" 字节");
            //return TRUE;
            break;
        }
    }
    return TRUE;
}

BUTTON函数OnSnd()中，调用打开对话框打开文件，并分包通过UDP发送

void CDemopicDlg::OnSnd()
{
    // TODO: Add your control notification handler code here
    int i,j,count;
    count = 0;
    HANDLE hFile;
    DWORD dwByteRead;
    CString strFilter,fileName;

    char* strText;
    strText = new char[113];

    strFilter = "All Files(*.jpg)|*.jpg";
    CFileDialog dlg(TRUE,NULL,NULL,
                    OFN_EXPLORER|OFN_HIDEREADONLY|OFN_ENABLESIZING|OFN_FILEMUSTEXIST,
                    strFilter);
    if(dlg.DoModal() == IDOK)
    {
        fileName = dlg.GetPathName();
        hFile = CreateFile(fileName,
                        GENERIC_READ,
                        0,
                        NULL,
                        OPEN_EXISTING,
                        FILE_ATTRIBUTE_NORMAL,
                        NULL);
        do
        {
            ReadFile(hFile,strText,iFrameLen,&dwByteRead,NULL);
            cSend = strText;
            sendto(sockfd,(char *)cSend,dwByteRead,0,(SOCKADDR*)&ServerAddress,sizeof(SOCKADDR));
            count++;
            for(i=0;i<20;i++)
            {
                for(j=0;j<10000;j++)
                {}
            }
        }while(dwByteRead != 0);
    }
    CloseHandle(hFile);
}

注意点：
测试过程中，子线程的recvfrom没有阻塞，是因为sockfd标示要在Dlg类下

声明初始化，通过参数将标示传递给子线程，不能只在子线程中声明和定义。