Biểu tượng bên ngoài chưa được giải quyết LNK2019

Question

Trước hết, tôi biết câu hỏi này là tất cả trên trang web này nhưng tôi đã xem xét hầu như tất cả chúng và dường như không thể tìm ra điều gì sai. Đây là trong VS 2012. Cảm ơn.

//Socket.h 
#pragma once 

#include <iostream> 
#include <WinSock2.h> 

using namespace std; 

const int STRLEN = 256; 

class Socket 
{ 
    protected: 
     WSADATA wsaData; 
     SOCKET mySocket; 
     SOCKET myBackup; 
     SOCKET acceptSocket; 
     sockaddr_in myAddress; 
    public: 
     Socket(); 
     ~Socket(); 
     bool SendData(char*); 
     bool RecvData(char*, int); 
     void CloseConnection(); 
     void GetAndSendMessage(); 
}; 

class ServerSocket : public Socket 
{ 
    public: 
     void Listen(); 
     void Bind(int port); 
     void StartHosting(int port); 
}; 

class ClientSocket : public Socket 
{ 
    public: 
     void ConnectToServer(const char *ipAddress, int port); 
}; 

Dưới đây là Socket.cpp

//Socket.cpp 


#include "stdafx.h" 
#include "Socket.h" 


Socket::Socket() 
{ 
    if(WSAStartup(MAKEWORD(2, 2), &wsaData) != NO_ERROR) 
    { 
     cerr<<"Socket Initialization: Error with WSAStartup\n"; 
     system("pause"); 
     WSACleanup(); 
     exit(10); 
    } 

    //Create a socket 
    mySocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); 

    if (mySocket == INVALID_SOCKET) 
    { 
     cerr<<"Socket Initialization: Error creating socket"<<endl; 
     system("pause"); 
     WSACleanup(); 
     exit(11); 
    } 

    myBackup = mySocket; 
} 

Socket::~Socket() 
{ 
    WSACleanup(); 
} 

bool Socket::SendData(char *buffer) 
{ 
    send(mySocket, buffer, strlen(buffer), 0); 
    return true; 
} 

bool Socket::RecvData(char *buffer, int size) 
{ 
    int i = recv(mySocket, buffer, size, 0); 
    buffer[i] = '\0'; 
    return true; 
} 

void Socket::CloseConnection() 
{ 
    //cout<<"CLOSE CONNECTION"<<endl; 
    closesocket(mySocket); 
    mySocket = myBackup; 
} 

void Socket::GetAndSendMessage() 
{ 
    char message[STRLEN]; 
    cin.ignore();//without this, it gets the return char from the last cin and ignores the following one! 
    cout<<"Send > "; 
    cin.get(message, STRLEN); 
    SendData(message); 
} 

void ServerSocket::StartHosting(int port) 
{ 
    Bind(port); 
    Listen(); 
} 

void ServerSocket::Listen() 
{ 
    //cout<<"LISTEN FOR CLIENT..."<<endl; 

    if (listen (mySocket, 1) == SOCKET_ERROR) 
    { 
     cerr<<"ServerSocket: Error listening on socket\n"; 
     system("pause"); 
     WSACleanup(); 
     exit(15); 
    } 

    //cout<<"ACCEPT CONNECTION..."<<endl; 

    acceptSocket = accept(myBackup, NULL, NULL); 
    while (acceptSocket == SOCKET_ERROR) 
    { 
     acceptSocket = accept(myBackup, NULL, NULL); 
    } 
    mySocket = acceptSocket; 
} 

void ServerSocket::Bind(int port) 
{ 
    myAddress.sin_family = AF_INET; 
    myAddress.sin_addr.s_addr = inet_addr("0.0.0.0"); 
    myAddress.sin_port = htons(port); 

    //cout<<"BIND TO PORT "<<port<<endl; 

    if (bind (mySocket, (SOCKADDR*) &myAddress, sizeof(myAddress)) == SOCKET_ERROR) 
    { 
     cerr<<"ServerSocket: Failed to connect\n"; 
     system("pause"); 
     WSACleanup(); 
     exit(14); 
    } 
} 

void ClientSocket::ConnectToServer(const char *ipAddress, int port) 
{ 
    myAddress.sin_family = AF_INET; 
    myAddress.sin_addr.s_addr = inet_addr(ipAddress); 
    myAddress.sin_port = htons(port); 

    //cout<<"CONNECTED"<<endl; 

    if (connect(mySocket, (SOCKADDR*) &myAddress, sizeof(myAddress)) == SOCKET_ERROR) 
    { 
     cerr<<"ClientSocket: Failed to connect\n"; 
     system("pause"); 
     WSACleanup(); 
     exit(13); 
    } 

} 

Và đây là stdafx.h

#pragma once 

#include "targetver.h" 

#define WIN32_LEAN_AND_MEAN    // Exclude rarely-used stuff from Windows headers 
// Windows Header Files: 
#include <windows.h> 

// C RunTime Header Files 
#include <stdlib.h> 
#include <malloc.h> 
#include <memory.h> 
#include <tchar.h> 


// TODO: reference additional headers your program requires here 
#include "Socket.h" 

Và đây là thông báo lỗi của tôi:

1>------ Build started: Project: Client, Configuration: Debug Win32 ------ 
1> stdafx.cpp 
1> Socket.cpp 
1> Client.cpp 
1> Generating Code... 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__accept@12 referenced in function "public: void __thiscall ServerSocket::Listen(void)" (?Listen@ServerSocket@@QAEXXZ) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__bind@12 referenced in function "public: void __thiscall ServerSocket::Bind(int)" (?Bind@ServerSocket@@QAEXH@Z) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__closesocket@4 referenced in function "public: void __thiscall Socket::CloseConnection(void)" (?CloseConnection@Socket@@QAEXXZ) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__connect@12 referenced in function "public: void __thiscall ClientSocket::ConnectToServer(char const *,int)" (?ConnectToServer@ClientSocket@@QAEXPBDH@Z) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__htons@4 referenced in function "public: void __thiscall ServerSocket::Bind(int)" (?Bind@ServerSocket@@QAEXH@Z) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__inet_addr@4 referenced in function "public: void __thiscall ServerSocket::Bind(int)" (?Bind@ServerSocket@@QAEXH@Z) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__listen@8 referenced in function "public: void __thiscall ServerSocket::Listen(void)" (?Listen@ServerSocket@@QAEXXZ) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__recv@16 referenced in function "public: bool __thiscall Socket::RecvData(char *,int)" (?RecvData@Socket@@QAE_NPADH@Z) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__send@16 referenced in function "public: bool __thiscall Socket::SendData(char *)" (?SendData@Socket@@QAE_NPAD@Z) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__socket@12 referenced in function "public: __thiscall Socket::Socket(void)" (??0Socket@@QAE@XZ) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__WSAStartup@8 referenced in function "public: __thiscall Socket::Socket(void)" (??0Socket@@QAE@XZ) 
1>Socket.obj : error LNK2019: unresolved external symbol __imp__WSACleanup@0 referenced in function "public: __thiscall Socket::Socket(void)" (??0Socket@@QAE@XZ) 
1>C:\Users\ajayp_000\documents\visual studio 2012\Projects\Client\Debug\Client.exe : fatal error LNK1120: 12 unresolved externals 
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== 

Answer 1

Vấn đề là bạn không liên kết với thư viện Ws2_32.lib. Để khắc phục điều này, bạn có thể thêm điều đó vào tab phụ thuộc bổ sung của cài đặt trình liên kết/đầu vào cho dự án của bạn. Ngoài ra (như được chỉ ra bởi SChepurin trong các ý kiến), bạn có thể thêm

#pragma comment(lib, "Ws2_32.lib") 

vào tệp nguồn của dự án của bạn.