visual studio無法解析靜態函數

Question

下面是代碼和輸出。 win_main.cpp

#include <Windows.h> 
#include <tchar.h> 

#include "d3d9_object.h" 

#pragma comment(lib, "d3d9.lib") 
#pragma comment(lib, "d3dx9.lib") 

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); 
WNDCLASSEX createWndClassEx(HINSTANCE); 
HWND createWindow(const wchar_t *caption, HINSTANCE); 
void exitWithFailure(const wchar_t *message, HINSTANCE); 

const wchar_t gszWndClassName[] = L"MainWindowClassName"; 
WNDCLASSEX gWndClassEx; 

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, PSTR, int iCmdShow) 
{ 
    HWND hwnd = NULL; 
    MSG msg = { 0 }; 
    BOOL bReturn; 

    WNDCLASSEX wndClassEx = createWndClassEx(hInstance); 
    if (!RegisterClassEx(&wndClassEx)) exitWithFailure(L"Cannot create window class", hInstance); 

    hwnd = createWindow(L"£d \u018Fditor", hInstance); 
    if (!hwnd) 
     exitWithFailure(L"Cannot create window", hInstance); 
    if (gpd39o->init(hwnd) == false) 
     exitWithFailure(L"Cannot initilize Direct3D", hInstance); 
    ShowWindow(hwnd, SW_MAXIMIZE); 
    UpdateWindow(hwnd); 
    if (!gpd39o->clear()) MessageBox(hwnd, L"Cannot clear device to color", L"Error!", MB_OK | MB_ICONERROR); 
    while ((bReturn = GetMessage(&msg, hwnd, 0, 0))) { 
     if (bReturn == -1) { 
      exitWithFailure(L"Message loop error", hInstance); 
     } 
     else { 
      TranslateMessage(&msg); 
      DispatchMessage(&msg); 
     } 
    } 

    gpd39o->deinit(); 
    UnregisterClass(gszWndClassName, hInstance); 
    return EXIT_SUCCESS; 
} 

void exitWithFailure(const wchar_t *message, HINSTANCE h) 
{ 
    MessageBox(NULL, message, L"Error!", MB_OK | MB_ICONERROR | MB_SYSTEMMODAL); 
    gpd39o->deinit(); 
    UnregisterClass(gszWndClassName, h); 
    exit(EXIT_FAILURE); 
} 

LRESULT CALLBACK WndProc(HWND h, UINT m, WPARAM w, LPARAM l) 
{ 
    if (m == WM_DESTROY) { 
     PostQuitMessage(0); 
     return 0; 
    } 

    return DefWindowProc(h, m, w, l); 
} 

HWND createWindow(const wchar_t *c, HINSTANCE h) 
{ 
    DWORD winStyle = WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | WS_MAXIMIZEBOX | WS_THICKFRAME; 
    return CreateWindowEx(WS_EX_APPWINDOW, gszWndClassName, c, winStyle, 
     CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 
     NULL, NULL, h, NULL); 
} 

WNDCLASSEX createWndClassEx(HINSTANCE h) 
{ 
    WNDCLASSEX w = { 0 }; 
    w.cbSize = sizeof(WNDCLASSEX); 
    w.hInstance = h; 
    w.style = CS_HREDRAW | CS_VREDRAW; 
    w.lpszClassName = (LPCWSTR)gszWndClassName; 
    w.lpfnWndProc = WndProc; 
    return w; 
} 

與引起問題的所有靜態成員的類。

#ifndef _D3D9_OBJECT_H_ 
#define _D3D9_OBJECT_H_ 

#include <d3d9.h> 
#include <d3dx9.h> 
#include <d3dx9math.h> 
#include "vertex_types.h" 

/* 
- sm_ - static member 
- d39 - Direct3D9 
- f - float 
*/ 
class D3D9Object 
{ 
public: 
    D3D9Object() { } 

    static bool init(HWND); 
    static void deinit(); 
    static bool clear(int color = D3DCOLOR_XRGB(0, 0, 0), float fZDepth = 1.0f); 

    static IDirect3D9 * sm_pId39; 
    static IDirect3DDevice9 * sm_pd39Device; 

    ~D3D9Object() { } 
private: 
    static HWND sm_hWnd; 
    static float sm_fAspectRatio; 
    static HRESULT sm_hResult; 

    static bool createDevice(); 
    static void setPresentParams(D3DPRESENT_PARAMETERS &); 
    static bool setDefaultRenderState(); 
}; 

extern D3D9Object * gpd39o; 

#endif 

d3d9_object.cpp 的#include 「d3d9_object.h」

IDirect3D9 * D3D9Object::sm_pId39; 
IDirect3DDevice9 * D3D9Object::sm_pd39Device; 
HRESULT D3D9Object::sm_hResult; 
HWND D3D9Object::sm_hWnd; 
float D3D9Object::sm_fAspectRatio; 

bool D3D9Object::init(HWND h) 
{ 
    if (!h) return false; 
    sm_hWnd = h; 
    if (!(sm_pId39 = Direct3DCreate9(D3D_SDK_VERSION))) return false; 
    if (!createDevice()) return false; 
    if (!setDefaultRenderState()) return false; 
    return true; 
} 

void D3D9Object::deinit() 
{ 
    if (sm_pId39) sm_pId39->Release(); 
    if (sm_pd39Device) sm_pd39Device->Release(); 
    sm_pId39 = NULL; 
    sm_pd39Device = NULL; 
    sm_hWnd = NULL; 
} 

bool D3D9Object::clear(int c, float z) 
{ 
    sm_hResult = sm_pd39Device->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, c, z, 0); 
    return sm_hResult == D3D_OK; 
} 

bool D3D9Object::setDefaultRenderState() 
{ 
    sm_hResult = sm_pd39Device->SetRenderState(D3DRS_LIGHTING, FALSE); 
    if (sm_hResult != D3D_OK) return false; 
    sm_hResult = sm_pd39Device->SetRenderState(D3DRS_ZENABLE, D3DZB_TRUE); 
    if (sm_hResult != D3D_OK) return false; 
    return true; 
} 

bool D3D9Object::createDevice() 
{ 
    if (sm_pd39Device || !sm_pId39) return false; 
    D3DPRESENT_PARAMETERS params = { 0 }; 
    setPresentParams(params); 
    sm_fAspectRatio = (float)params.BackBufferWidth/(float)params.BackBufferHeight; 
    sm_hResult = sm_pId39->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, sm_hWnd, D3DCREATE_HARDWARE_VERTEXPROCESSING, 
     &params, &sm_pd39Device); 
    if (sm_hResult != D3D_OK) { 
     sm_hResult = sm_pId39->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, sm_hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, 
      &params, &sm_pd39Device); 
     if (sm_hResult != D3D_OK) return false; 
    } 
    return true; 
} 

void D3D9Object::setPresentParams(D3DPRESENT_PARAMETERS &p) 
{ 
    ZeroMemory(&p, sizeof(D3DPRESENT_PARAMETERS)); 
    p.hDeviceWindow = sm_hWnd; 
    p.BackBufferCount = 1; 
    p.SwapEffect = D3DSWAPEFFECT_FLIP; 
    p.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE; 
    p.EnableAutoDepthStencil = TRUE; 
    p.AutoDepthStencilFormat = D3DFMT_D16; 
    RECT r = { 0 }; 
    GetClientRect(sm_hWnd, &r); 
    p.Windowed = true; 
    p.BackBufferWidth = r.right; 
    p.BackBufferHeight = r.bottom; 
    p.BackBufferFormat = D3DFMT_UNKNOWN; 
} 

D3D9Object gd39Object; 
extern D3D9Object * gpd39o = &gd39Object; 

這裏是輸出

1>------ Build started: Project: 3DEditor, Configuration: Debug Win32 ------ 
1> win_main.cpp 
1> d3d9_object.h 
1> d3d9_object.cpp 
1> Generating Code... 
1>Debug\d3d9_object.obj : warning LNK4042: object specified more than once; extras ignored 
1>win_main.obj : error LNK2019: unresolved external symbol "public: static bool __cdecl D3D9Object::init(struct HWND__ *)" (?init@D3D9Object@@SA_NPAUHWND__@@@Z) referenced in function _WinMain@16 
1>win_main.obj : error LNK2019: unresolved external symbol "public: static void __cdecl D3D9Object::deinit(void)" (?deinit@D3D9Object@@SAXXZ) referenced in function "void __cdecl exitWithFailure(wchar_t const *,struct HINSTANCE__ *)" (?exitWithFailure@@YAXPB_WPAUHINSTANCE__@@@Z) 
1>win_main.obj : error LNK2019: unresolved external symbol "public: static bool __cdecl D3D9Object::clear(int,float)" (?clear@D3D9Object@@SA_NHM@Z) referenced in function _WinMain@16 
1>C:\Users\User\documents\visual studio 2013\Projects\3DEditor\Debug\3DEditor.exe : fatal error LNK1120: 3 unresolved externals 
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== 

你能告訴我什麼可能導致LNK4042？我沒有得到多次指定對象的位置。我試圖谷歌LNK2019，但我發現的所有主題都是語法問題。我檢查了我能找到的所有東西，但代碼似乎很好（如果不是，我會很高興，你只是將我的錯誤指向我）。有時，當我對代碼進行小的更改時，鏈接器會成功，但是在幾次編譯之後，它會再次失敗。另外，在我添加「清除」功能之前，它正在工作，我添加了這個小函數，並且從那時起它只工作過一次（在我添加此函數之前，有時鏈接程序確實失敗，但現在它有時會成功）。我知道還有其他的方式來實現單身人士，但我有類似的代碼，它工作正常。謝謝

Answer 1

您的編譯輸出顯示，你以某種方式設法強制編譯器實際上編譯d3d9_object.h文件。這是完全不能接受的。你不應該編譯頭文件。頭文件應該包含在.cpp文件中，而不是自行編譯。

正因爲如此的問題，你的d3d9_object.h，作爲強制供給到編譯器後，產生d3d9_object.obj文件，它破壞（重寫）從d3d9_object.cpp獲得正確d3d9_object.obj文件。這導致LNK4042和更多鏈接器錯誤。

不要試圖編譯d3d9_object.h。瞭解它如何設法編譯並解決問題。