关于recvfrom（）的问题 - 编程论坛

#2

rjsp2011-05-09 11:49

看你的socket设置，是否为阻塞

#3

hellovfp2011-05-09 13:34

异步模式了？

#4

安普留香2011-05-09 17:41

在单核情况下不会出现这种情况

#5

安普留香2011-05-10 11:48

程序代码：

#include <stdio.h>
#include <Winsock2.h>
#include <Windows.h>
    SOCKADDR_IN cln_in;
    SOCKADDR_IN sock_in;
    int cz=sizeof(SOCKADDR_IN);
    SOCKET ser_socket;

    DWORD CALLBACK New_Thread(LPVOID lpParameter);
void main()
{
    WORD wVersionRequested;
    WSADATA wsaData;
    int err;

    wVersionRequested = MAKEWORD( 2, 2 );

    err = WSAStartup( wVersionRequested, &wsaData );
    if ( err != 0 ) {

        return;
    }


    if ( LOBYTE( wsaData.wVersion ) != 2 ||
        HIBYTE( wsaData.wVersion ) != 2 ) {

        WSACleanup( );
        return;
    }
    ser_socket=socket(AF_INET,SOCK_DGRAM,0);
    HANDLE hThread=CreateThread(NULL,0,New_Thread,0,0,0);
    CloseHandle(hThread);

    sock_in.sin_addr.S_un.S_addr=htonl(INADDR_ANY);
    sock_in.sin_family=AF_INET;
    sock_in.sin_port=htons(9527);

    bind(ser_socket,(SOCKADDR*)&sock_in,sizeof(SOCKADDR_IN));
       char sendbuf[200];
    while(1)
    {
        gets(sendbuf);

    sendto(ser_socket,sendbuf,200,0,(SOCKADDR*)&cln_in,cz);
    }
    closesocket(ser_socket);
}

    DWORD CALLBACK New_Thread(LPVOID lpParameter)
{
        char recvbuf[200]={'\0'};
    char fobuf[300];
    while(true)
    {
        recvfrom(ser_socket,recvbuf,200,0,(SOCKADDR*)&cln_in,&cz);
        printf("hhhh\n");
        sprintf(fobuf,"%s say:%s",inet_ntoa(cln_in.sin_addr),recvbuf);
        printf("%s\n",fobuf);
    }
};

以上是代码

[ 本帖最后由安普留香于 2011-5-10 11:53 编辑 ]

#6

安普留香2011-05-11 19:45

程序代码：

#include <stdio.h>
#include <Winsock2.h>
#include <Windows.h>

SOCKET cln_socket;
SOCKADDR_IN addr;
SOCKADDR_IN ser_addr;
int cz=sizeof(SOCKADDR_IN);
DWORD CALLBACK New_Thread(LPVOID lpParameter);
void main()
{

    WORD wVersionRequested;
    WSADATA wsaData;
    int err;

    wVersionRequested = MAKEWORD( 2, 2 );

    err = WSAStartup( wVersionRequested, &wsaData );
    if ( err != 0 ) {
        /* Tell the user that we could not find a usable */
        /* WinSock DLL.                                  */
        return;
    }

    /* Confirm that the WinSock DLL supports 2.2.*/
    /* Note that if the DLL supports versions greater    */
    /* than 2.2 in addition to 2.2, it will still return */
    /* 2.2 in wVersion since that is the version we      */
    /* requested.                                        */

    if ( LOBYTE( wsaData.wVersion ) != 2 ||
        HIBYTE( wsaData.wVersion ) != 2 ) {
        /* Tell the user that we could not find a usable */
        /* WinSock DLL.                                  */
        WSACleanup( );
        return;
    }
    cln_socket=socket(AF_INET,SOCK_DGRAM,0);
    //HANDLE h_thread=CreateThread(NULL,0,New_Thread,0,0,0);
    //CloseHandle(h_Thread);

    ser_addr.sin_addr.S_un.S_addr=inet_addr("127.0.0.1");
    ser_addr.sin_port=htons(9527);
    ser_addr.sin_family=AF_INET;
    char sendbuf[200]={'\0'};
    HANDLE h_Thread=CreateThread(NULL,0,New_Thread,0,0,0);
    CloseHandle(h_Thread);
    while(true)
    {
        gets(sendbuf);
        sendto(cln_socket,sendbuf,200,0,(SOCKADDR*)&ser_addr,cz);
    }
    closesocket(cln_socket);
}
DWORD CALLBACK  New_Thread(LPVOID lpParamter)
{
    char recvbuf[200]={'\0'};
    while(true)
    {

    recvfrom(cln_socket,recvbuf,200,0,(SOCKADDR*)&ser_addr,&cz);
    if(recvbuf[0]!='\0')

    {
    //printf("hhhh\n");
    printf("%s :%s\n",inet_ntoa(ser_addr.sin_addr),recvbuf);
    }
    }
}

以上是客户端代码
最后一个问题
为什么客户端发送一次数据之后才能接受到服务端的数据

#7

玩出来的代码2011-05-11 21:22

LZ应该先将基础知识学好。
你5L贴的代码那些明显错误是不可饶恕的

并且在5L也能看出你对socket的不了解，6L虽然改了些，依然让人、、有书得话好好看书，对比着看哪里有问题，学着自己调试，也注意自己的代码格式，解决方法。别忘了还有MSDN,baidu,google.

#8

安普留香2011-05-12 22:01

以上代码都已经通过编译，正常运行
请楼上指出错误

#9

安普留香2011-05-12 22:08

还有问题是
1 为什么双核情况下服务端会先输出若干，单核运行情况则不会
2 客户端要发送一次数据之后，才能正常接收到服务端数据
哪位知道指点下