为什么窗口不加载？ [Win32] [重复]答案

【问题标题】：Why is the Window not loading ? [Win32] [duplicate]为什么窗口不加载？ [Win32] [重复]
【发布时间】：2020-11-18 07:33:47
【问题描述】：

您好，我是学习 DirectX 11 Api 的初学者，我在 Youtube 上看到了教程，并为 Windows 实现了这个 Wrapper 但是窗口很多 Loading 我得到的唯一调试字符串只是 INIT_WINDOw 方法中的 Register Class Failed 字符串。没有别的弹出。请帮我解决一下这个。 DX_Wrapper.cpp

#include "Headers/Dx_Wrapper.h"

//Global One For Defining __stdcall for WindowProc
namespace
{
    Wrapper* g_wrapper = nullptr;
}

//Main WINDOW Message processing Window Procedure 
LRESULT CALLBACK WINDOWPROC(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    if (g_wrapper) return g_wrapper->MessageProcedure(hwnd, msg, wparam, lparam);
    else return DefWindowProc(hwnd, msg, wparam, lparam);
}
//Constructor For the Instance
Wrapper::Wrapper(HINSTANCE hinstance)
{
    m_hinstance = hinstance;
    m_hwnd = NULL;
    m_winheight = 600;
    m_winwidth = 800;
    m_wintitle = L"DirectX";
    m_winstyles = WS_OVERLAPPEDWINDOW;
    g_wrapper = this;
}
Wrapper::~Wrapper()
{

}

//Window Loop Manager Attached to the WINDOWPROC function
int32_t Wrapper::Run()
{
    
    MSG message = { 0 };

    while (WM_QUIT != message.message)
    {
        //Message Check If Quit 
        if (PeekMessage(&message, NULL, NULL, NULL, PM_REMOVE))
        {
            TranslateMessage(&message);
            DispatchMessage(&message);
        }
        //If Not Quit
        else
        {
            UPDATE_FRM(5.5f);

        }
    }

    return static_cast<int>(message.wParam);
}

bool Wrapper::Init()
{

    if (!INIT_WINDOW() == true)
    {
        return false;
    }
    return true;

}

LRESULT  Wrapper::MessageProcedure(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    switch (msg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;

    default:
        return DefWindowProc(hwnd, msg, wparam, lparam);

    }
}

void Wrapper::UPDATE_FRM(float delta_time)
{
    
}
void Wrapper::RENDER_FRM(float delta_time)
{

}

//Registering Classical Windows Class Function 
bool Wrapper::INIT_WINDOW()
{
    //THE CLASS REGISTERING STUFF

    WNDCLASSEX win_class;
    
    win_class.cbClsExtra = 0;
    win_class.hInstance = m_hinstance;
    win_class.cbWndExtra = 0;
    win_class.style = CS_HREDRAW | CS_VREDRAW;
    win_class.cbSize = sizeof(WNDCLASSEX);
    win_class.lpfnWndProc = WINDOWPROC;
    win_class.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);
    win_class.lpszMenuName = NULL;
    win_class.lpszClassName = L"dx_main_class";
    win_class.hCursor = 0;
    RegisterClassEx(&win_class);

    if (!RegisterClassEx(&win_class))
    {
        OutputDebugString(L"Registering Class Failed");
        return false;
    }

    RECT r = {0,0,m_winwidth,m_winheight};

    AdjustWindowRect(&r, m_winstyles, FALSE);

    uint_fast16_t f_width = r.right - r.left;
    uint_fast16_t f_height = r.bottom - r.top;

    uint_fast16_t f_width_final = uint_fast16_t(GetSystemMetrics(SM_CXSCREEN) / 2 - f_width / 2);
    uint_fast16_t f_height_final = uint_fast16_t(GetSystemMetrics(SM_CYSCREEN) / 2 - f_height / 2);



    m_hwnd = CreateWindow(L"dx_main_class", m_wintitle, m_winstyles, f_width_final, f_height_final, f_width, f_height, NULL, NULL, m_hinstance, NULL);

    if (!m_hwnd)
    {
        OutputDebugString(L"Window Could Not be Created ");
        return false;
    }

    ShowWindow(m_hwnd, SW_SHOW);

    return true;
}

DX_Wrapper.h

#include <Windows.h>
#include <stdint.h>
#include <string>
#define WIN32_LEAN_AND_MEAN
class Wrapper
{
public:
    Wrapper(HINSTANCE hinstance);
    virtual ~Wrapper();
    int32_t Run();
    virtual bool Init();
    virtual LRESULT  MessageProcedure(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam);
    virtual void  UPDATE_FRM(float delta_time) = 0;
    virtual void  RENDER_FRM(float delta_time) = 0;

protected:

    HWND m_hwnd = nullptr;
    HINSTANCE m_hinstance = nullptr;
    uint_fast16_t m_winwidth = 0;
    uint_fast16_t m_winheight = 0;
    LPCWSTR m_wintitle = L"";
    DWORD m_winstyles = 0;

protected:

    bool INIT_WINDOW();

};

这是主应用程序 CPP 文件

#include "Headers/Dx_Wrapper.h"
class Application : public Wrapper
{
public:
    Application(HINSTANCE hinstance);
    

    bool Init() override;
    void UPDATE_FRM(float delta_time) override;
    void RENDER_FRM(float delta_time) override;
};
Application::Application(HINSTANCE hinstance) : Wrapper(hinstance)
{

}

bool Application::Init()
{
    return Wrapper::Init();
    
}
void Application::UPDATE_FRM(float delta_time)
{

}
void Application::RENDER_FRM(float delta_time)
{

}
int32_t WINAPI WinMain(__in HINSTANCE hinstance, __in_opt HINSTANCE hprevinstance, __in LPSTR cmdline, __in int cmdshow)
{
    Application m_app(hinstance);
    if (!m_app.Init()) return 1;


    return m_app.Run();
}

我的问题是 OutputDebugString 仅显示 INIT_WINDOW 函数中的注册类失败字符串。我不知道为什么它是错误的。窗口没有运行。

【问题讨论】：

您尝试注册课程两次。如果您想了解更多信息，请阅读文档。他们会告诉您如何以及何时调用 GetLastError 以找出任何 api 调用失败的原因。
关注documentation："cbSize：此结构的大小，以字节为单位。将此成员设置为sizeof(WNDCLASSEX)。"我>

标签： c++ windows winapi visual-c++

【解决方案1】：

首先你调用了两次RegisterClassEx函数，所以你需要删除第一次调用：

//RegisterClassEx(&win_class);
if (!RegisterClassEx(&win_class))
{
    OutputDebugString(L"Registering Class Failed");
    return false;
}

那么你需要设置WNDCLASSEX的每个成员。

所以可以参考以下代码：

WNDCLASSEX win_class;
win_class.cbSize = sizeof(WNDCLASSEX);
win_class.style = CS_HREDRAW | CS_VREDRAW;
win_class.lpfnWndProc = WINDOWPROC;
win_class.cbClsExtra = 0;
win_class.cbWndExtra = 0;
win_class.hInstance = m_hinstance;
win_class.hIcon = LoadIcon(NULL, IDI_APPLICATION);
win_class.hCursor = 0;
win_class.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);
win_class.lpszMenuName = NULL;
win_class.lpszClassName = L"dx_main_class";
win_class.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

【讨论】：