c – 如果我将WndProc移动到另一个cpp文件,则“未解析的外部_WinMain @ 16”

对于Windows应用程序,我试图让CreateWindow()和WndProc()(或我的版本)成为在_tWinMain()开头创建的单例类的一部分但是因为尝试将函数转移到GameHandler .h和GameHandler.cpp我一直得到“未解析的外部符号_WinMain @ 16”.它们最初是main.cpp中的全局函数,一切都编译得很好然后我决定将它们移动到GameHandler,因为我得到的是未解析的外部,即使我试图将它们移回main.cpp.

我在VS2010中这样做,该项目是作为Windows应用程序创建的,并且在属性中没有设置特定的入口点(我仔细检查过,因为我发现的每个解决方案都说是因为它是一个控制台应用程序 – 这不是’ T).

我目前拥有的代码如下所示.实际项目有几千行其他代码我遗漏了,因为我认为它不相关(但很高兴证明是错误的.虽然实际的窗口创建代码是相关的,但我不认为代码本身是问题(除了我留下的),它是GameWindowProc()& /或CreateGameWindow()的位置或它们的调用方式.实际的窗口创建代码取自NeHe’s tutorial.尝试仅编译以下代码给出上述未解决的外部因素.

main.cpp中：

#include <Windows.h>
#include "GameManager.h"

#ifndef USEGMGR
bool CreateGameWindow(char* title, int width, int height, int bits, bool fullScreenFlag);
LRESULT CALLBACK GameWindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
#endif

int APIENTRY _tWinMain(HINSTANCE hInst, HINSTANCE hPrevInst, 
                        LPTSTR lpCmdLine, int nCmdShow)
{
    GameManager::Startup();
    GameManager* GMgr = GameManager::GetInstance();

    GMgr->SetProgramState(GAME_MODE);
    while(GMgr->GetProgramState() != GAME_MODE) // Normally this would be if (State != GAME_QUIT)
    { /* do game related stuff */ }

    GameManager::Shutdown();
    return 0;
}

#ifndef USEGMGR
bool CreateGameWindow(char* title, int width, int height, int bits, bool fullScreenFlag)
{
    // Fairly complex but flexible creation code, taken from NeHe's tutorials. Of relevant interest is:
    WNDCLASS        wc;                             // Windows Class Structure
    wc.lpfnWndProc  = (WNDPROC) GameWindowProc;  // WndProc Handles Messages
    if (!RegisterClass(&wc))                         // Attempt To Register The Window Class
    {
        MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
        return false;
    }
    return true;
}

LRESULT CALLBACK GameWindowProc(HWND    hWnd,            // Handle For This Window
    UINT    uMsg,            // Message For This Window
    WPARAM    wParam,            // Additional Message Information
    LPARAM    lParam)            // Additional Message Information
{
    // various custom message handling, if not processed:
    return DefWindowProc(hWnd,uMsg,wParam,lParam);
}
#endif

在GameManager.h中：

#ifndef GAMEMANAGER_H
#define GAMEMANAGER_H
#define USEGMGR // makes CreateGameWindow() and GameWindowProc() methods in GameManager instead of global

#include <Windows.h>

enum ProgramState
{
    GAME_MODE,
    GAME_QUIT,
};

class GameManager
{
public:
    static void             Startup();
    static void             Shutdown();
    static GameManager*     GetInstance();
    void                    Update(); // code not shown, check quit key etc
#ifdef USEGMGR
    const bool              CreateGameWindow(char* title, int width, int height, int bits, bool fullScreenFlag);
    static LRESULT CALLBACK GameWindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
#endif
    void                    KillGameWindow(void);
    const int                GetProgramState() const;
    void                    SetProgramState(const int& newMode);
private:
    GameManager();
    ~GameManager();
    GameManager(const GameManager&);
    GameManager& operator=(const GameManager&);
    HINSTANCE                m_hInstance;
    HWND                    m_hWnd;        
    HDC                        m_hDC;        
    static GameManager*        s_instance;
    int                        m_programState; // uses ProgramState enum
};
#endif

在GameManager.cpp中：

#include "GameManager.h"
#include <Windows.h>
#include <assert.h>

#ifndef USEGMGR
extern bool CreateGameWindow(char* title, int width, int height, int bits, bool fullScreenFlag);
#endif
GameManager*        GameManager::s_instance    = NULL;
GameManager::GameManager(){}
GameManager::~GameManager(){}


void GameManager::Startup()
{
    assert(s_instance == NULL);
    s_instance = new GameManager;
#ifdef USEGMGR
    if (! (s_instance->CreateGameWindow("Game Window", 800, 600, 32, true )) )
#else
    if (! (CreateGameWindow("Game Window", 800, 600, 32, true )) )
#endif
        assert("CreateGameWindow failed! Need an error here"); // Quit If Window Was Not Created - clean this up later    
}

void GameManager::Shutdown()
{
    assert(s_instance != NULL);
    delete s_instance;
    s_instance = NULL;
}

GameManager* GameManager::GetInstance(){return s_instance;}

void GameManager::Update(){/* msg handling, watch for quit key, etc */}
const int GameManager::GetProgramState() const{return s_instance->m_programState;}
void GameManager::SetProgramState(const int& newState){s_instance->m_programState = newState;}

#ifdef USEGMGR
const bool GameManager::CreateGameWindow(char* title, int width, int height, int bits, bool fullScreenFlag)
{
    // Fairly complex but flexible creation code, taken from NeHe's tutorials. Of relevant interest is:
    WNDCLASS        wc;                             // Windows Class Structure
    wc.lpfnWndProc  = (WNDPROC) GameManager::GameWindowProc;  // WndProc Handles Messages
    if (!RegisterClass(&wc))                         // Attempt To Register The Window Class
    {
        MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
        return false;
    }
    return true;
}

LRESULT CALLBACK GameManager::GameWindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    // various custom message handling, if not processed:
    return DefWindowProc(hWnd,uMsg,wParam,lParam);
}
#endif    

正如您所看到的,我已经设置了一些预处理器条件,以便在main.cpp中或作为GameManager的一部分之间切换麻烦的函数.在GameManager.h的开头注释#define USEGMGR,将它们作为main.cpp中的全局函数.

有人可以告诉我我做错了什么吗？

编辑：删除评论,如果你让它运行不能退出.

解决方法:

加

#include <tchar.h>

到main.cpp的顶部,以便正确定义_tWinMain宏.

如果你没有宏定义会发生什么,你最终会在目标文件中找到一个名为_tWinMain()的函数(或者名称的某个错位版本,如？_tWinMain @@ YGHPAUHINSTANCE __ @@ 0PADH @ Z()),但链接器和运行时初始化代码正在寻找WinMain()或wWinMain().他们找不到.

&LT TCHAR.H&GT定义一个宏,将名称_tWinMain()转换为其他所有要查找的名称之一.在开始重构之前(很可能是间接的),你必须拥有包含那个标题的东西,并以某种方式丢失它.

或者您可以免除宏版本并将函数命名为WinMain或wWinMain(无论您是否正在为UNICODE构建,都应该可以使用它).如果这样做,只需记住更改LPTSTR参数声明以匹配您选择的声明.

标签：c,winapi,unresolved-external
来源： https://codeday.me/bug/20190729/1573354.html