如何防止包含两次头文件？问题是我包括了在MyClass.h中然后我将MyClass.h包含在许多文件中,因此它包含多次并发生重定义错误.怎么预防？
我正在使用#pragma而不是包含警卫,我想这很好.
MyClass.h:
// MyClass.h
#pragma once
#include <winsock2.h>
class MyClass
{
// methods
public:
MyClass(unsigned short port);
virtual ~MyClass(void);
};
编辑:我得到的错误很少
c:\program files\microsoft sdks\windows\v6.0a\include\ws2def.h(91) : warning C4005: 'AF_IPX' : macro redefinition
c:\program files\microsoft sdks\windows\v6.0a\include\winsock.h(460) : see previous definition of 'AF_IPX'
c:\program files\microsoft sdks\windows\v6.0a\include\ws2def.h(124) : warning C4005: 'AF_MAX' : macro redefinition
c:\program files\microsoft sdks\windows\v6.0a\include\winsock.h(479) : see previous definition of 'AF_MAX'
c:\program files\microsoft sdks\windows\v6.0a\include\ws2def.h(163) : warning C4005: 'SO_DONTLINGER' : macro redefinition
c:\program files\microsoft sdks\windows\v6.0a\include\winsock.h(402) : …我不能在msvc ++ 2010项目中包含WinSock2.h.起初我虽然这是我做错了,所以我创建了一个空项目来测试我的理智.空项目如下
#include <Windows.h>
#include <WinSock2.h>
int main(void){
system("echo Hello World");
system("pause");
return 0;
};
它在没有行的情况下编译和工作正常,#include <WinSock2.h>但是当我尝试包含WinSock2.h时,它会失败并出现一长串错误.
错误:
1> Main.cpp
1>c:\program files\microsoft sdks\windows\v7.0a\include\ws2def.h(91): warning C4005: 'AF_IPX' : macro redefinition
1> c:\program files\microsoft sdks\windows\v7.0a\include\winsock.h(460) : see previous definition of 'AF_IPX'
1>c:\program files\microsoft sdks\windows\v7.0a\include\ws2def.h(131): warning C4005: 'AF_MAX' : macro redefinition
1> c:\program files\microsoft sdks\windows\v7.0a\include\winsock.h(479) : see previous definition of 'AF_MAX'
1>c:\program files\microsoft sdks\windows\v7.0a\include\ws2def.h(168): warning C4005: 'SO_DONTLINGER' : macro redefinition
1> c:\program files\microsoft sdks\windows\v7.0a\include\winsock.h(402) : see previous definition of 'SO_DONTLINGER' …我使用Visual Studio 2012，并尝试使静态库UDT正常工作。不幸的是，我无法编译将UDT库链接到其自身的项目，我在Windows SDK标头中遇到有关类型或宏重新定义的159个奇怪的错误。
c:\program files\windows kits\8.0\include\shared\ws2def.h(96): warning C4005: 'AF_IPX' : macro redefinition
2> c:\program files\windows kits\8.0\include\um\winsock.h(452) : see previous definition of 'AF_IPX'
2>c:\program files\windows kits\8.0\include\shared\ws2def.h(136): warning C4005: 'AF_MAX' : macro redefinition
2> c:\program files\windows kits\8.0\include\um\winsock.h(471) : see previous definition of 'AF_MAX'
2>c:\program files\windows kits\8.0\include\shared\ws2def.h(173): warning C4005: 'SO_DONTLINGER' : macro redefinition
2> c:\program files\windows kits\8.0\include\um\winsock.h(394) : see previous definition of 'SO_DONTLINGER'
2>c:\program files\windows kits\8.0\include\shared\ws2def.h(217): error C2011: 'sockaddr' : 'struct' type redefinition
2> c:\program files\windows kits\8.0\include\um\winsock.h(477) : see declaration …
C++表达新手,在关注winsock教程之后,遇到了无数错误.已将包含Windows SDK 7.1的链接链接到属性.我错过了什么？
#include <winsock2.h>
#include <stdio.h>
#include <stdafx.h>
#pragma comment(lib, "Ws2_32.lib")
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
int main(int argc, char **argv)
{
WSADATA wsaData;
SOCKET SendingSocket;
// Server/receiver address
SOCKADDR_IN ServerAddr, ThisSenderInfo;
// Server/receiver port to connect to
unsigned int Port = 7171;
int RetCode;
// Be careful with the array bound, provide some checking mechanism...
char sendbuf[1024] = "This is a test string from sender";
int BytesSent, nlen;
// Initialize Winsock version 2.2
WSAStartup(MAKEWORD(2,2), &wsaData);
printf("Client: Winsock DLL …