winsock客戶端和服務器通信

Question

對不起，我知道我在過去一天中發佈了與同一主題相關的線程，但是我遇到了另一個問題。

server.cpp

/*Server */ 
#define _WIN32_WINNT 0x501 
#include <iostream> 
#include <windows.h> 
#include <winsock2.h> 
#include <ws2tcpip.h> 
using namespace std; 

const int winsock_version = 2; 
#define PORT "3490" 
#define MAX_NUM_CONNECTIONS 10 

int main(void){ 

    WSADATA wsadata; 

    if (WSAStartup(MAKEWORD(winsock_version,0),&wsadata) == 0){ 
     cout<<"-WSAStartup Initialized." << endl; 

     struct addrinfo hints,*res; 
     int sock_fd; 

     memset(&hints,0,sizeof hints); 
     hints.ai_family = AF_UNSPEC; 
     hints.ai_socktype = SOCK_STREAM; 
     hints.ai_flags = AI_PASSIVE; 

     if (getaddrinfo(NULL,PORT,&hints,&res) != 0){ 
      cout<<"-Call to getaddress was unsucceful." << endl; 
     } 

     if((sock_fd = socket(res->ai_family,res->ai_socktype,res->ai_protocol)) == -1){ 
      cout<<"-Unable to Create socket." << endl; 
     } 

     if ((bind(sock_fd, res->ai_addr, res->ai_addrlen)) != -1){ 
      cout<<"-binding successful." << endl; 
     } 

     if ((listen(sock_fd,MAX_NUM_CONNECTIONS)) != -1){ 
      cout<<"-Listening for incoming connections." << endl; 
     } 
     //------------------------------------------------------------- 

     struct sockaddr_storage incming_info; 
     socklen_t sin_size; 
     sin_size = sizeof incming_info; 

     int new_fd; 

     new_fd = accept(sock_fd, (struct sockaddr*)&incming_info,&sin_size); 
     if (new_fd == -1){ 
      cout<<"-Accepting error." << endl; 
     } 
     if(new_fd == INVALID_SOCKET){ 
      cout<<"-INVALID SOCKET ERROR." << endl; 
     } 
     //------------------------------------------------------------- 

     cout<<"Connected?" << endl; 
     char buffer[128]; 
     while(true){ 
      int ret_val; 

      ret_val = recv(new_fd,buffer,sizeof(buffer),0); 
      if(ret_val == -1){ 
       cout<<"Receiving Error." << endl; 
       break; 
      }else if(ret_val == 0){ 
       cout<<"Connection has been closed!." << endl; 
       break; 
      }else if(ret_val > 0){ 
       cout<<"Server: " << buffer<< endl; 
      } 
     } 

     cout<<"-Closing connection" << endl; 
     closesocket(new_fd); 
    }else{ 
     cout<<"-WSAStartup Initialization failed." << endl; 
     if(WSACleanup()!=0){ 
      cout<<"-WSACleanup Successful." << endl; 
     }else{ 
      cout<<"-WSACleanup Failed." << endl; 
     } 
    } 
    return 0; 
} 

client.cpp

/*client*/ 
#define _WIN32_WINNT 0x501 
#include <iostream> 
#include <windows.h> 
#include <winsock2.h> 
#include <ws2tcpip.h> 
using namespace std; 

#define PORT "3490" 
#define SERVER "localhost" 
const int winsockVersion = 2; 


int main(void){ 

    WSADATA wsadata; 
    if ((WSAStartup(MAKEWORD(2,0),&wsadata)) == 0){ 
     cout<<"-WSAStartup Initialized." << endl; 

     struct addrinfo hints, *res; 
     int sockfd; 

     memset(&hints,0,sizeof hints); 
     hints.ai_family = AF_UNSPEC; 
     hints.ai_socktype = SOCK_STREAM; 

     if (getaddrinfo(SERVER,PORT,&hints,&res) != 0){ 
      cout<<"-getaddrinfo unsuccessful." << endl; 
     } 

     if ((sockfd = socket(res->ai_family,res->ai_socktype,res->ai_protocol)) == -1){ 
      cout<<"-Unable to create socket." << endl; 
     } 

     if ((connect(sockfd,res->ai_addr,res->ai_addrlen)) != -1){ 
      cout<<"-Connection Established." << endl; 
     } 

     cout<<"-Client connecting to: " << res->ai_addr << endl; 

     while(true){ 
      char text_buff[128]; 
      cout<<"Enter text: "; 
      cin>>text_buff; 
      if((send(sockfd,text_buff,sizeof(text_buff),0)) != -1){ 
       cout<<"-text_buff sent!." << endl; 
       break; 
      } 
     closesocket(sockfd); 

     } 

    }else{ 
     cout<<"-WSAStartup Initialization failed." << endl; 
     if(WSACleanup()!=0){ 
      cout<<"-WSACleanup Successful." << endl; 
     }else{ 
      cout<<"-WSACleanup Failed." << endl; 
     } 
    } 

    return 0; 
} 

我可以運行服務器和客戶端很好，但我只能發送一個字（不能發一個句子出於某種原因）從在服務器控制檯上打印出來的客戶端，但一旦在服務器控制檯上打印出來，就會輸出「接收錯誤」並關閉。

Answer 1

兩個問題
是隻讀取，直到第一空間。你可以使用std :: string。
2. send(sockfd,text_buff,sizeof(text_buff),0)使用strlen(text_buff) + 1而不是sizeof(text_buff)。
如果使用的std :: string，然後嘗試

string line; 
send(sockfd, line.c_str(),line.length()+1,0) 

Answer 2

您不能假設對send()的單個調用就足夠了（並且對於recv()也是如此）。您需要遍歷數據，直到發送/接收完所有數據。另外，你可能不希望總是發送128個字符，而應該發送所需的長度（並且在消息中包含終止符或前綴長度）。

Answer 3

嘗試用std :: string和std :: getline替換使用char text_buff的輸入。

while(true) 
{ 
    std::string line; 
    std::cout << "Enter text: "; 
    std::getline(cin, line); 
    if(send(sockfd, text_buff.c_str(), text_buff.size(), 0)) != -1) 
    { 
     std::cout << "-text_buff sent!." << std::endl; 
     break; 
    } 
    closesocket(sockfd); 
} 

我不知道你的循環有你似乎只是循環退出第一次成功地發送任何東西。