Win32窗口不显示

Question

I am working on a directX application and I'm trying to set up a window. But the problem is that my window isn't showing up instead displaying my popup I made for when the window fails to create. I have made windows multiple times and now it is not working. The only thing that I changed in my routine is that I switched my application to a 64 bit application instead of a 32 bit application. I have a 64 bit computer and it should work.

main.cpp

#include "Render\window.h"

int CALLBACK WinMain(HINSTANCE appInstance, HINSTANCE prevInstance, LPSTR cmdLine, int cmdCount)
{
    Window window("Program", 800, 600);

    MSG msg = { 0 };
    while (true)
    {
        if (PeekMessage(&msg, 0, 0, 0, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);

            if (msg.message == WM_QUIT) break;
        }
    }

    return 0;
}

window.h

#pragma once

#include <Windows.h>

class Window
{
private:
    const char* const m_Title;
    const int m_Width;
    const int m_Height;
    HWND m_Handler;
public:
    Window(const char* title, int width, int height);

    inline HWND GetHandler() const { return m_Handler; }
private:
    void Init();
};

window.cpp

#include "window.h"

LRESULT CALLBACK WinProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    if (msg == WM_DESTROY || msg == WM_CLOSE)
    {
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, msg, wparam, lparam);
}

Window::Window(const char* title, int width, int height)
    : m_Title(title), m_Width(width), m_Height(height)
{
    Init();
}

void Window::Init()
{
    WNDCLASS windowClass;
    windowClass.style = CS_OWNDC;
    windowClass.lpfnWndProc = WinProc;
    windowClass.hCursor = LoadCursor(nullptr, IDC_ARROW);
    windowClass.lpszClassName = L"MainWindow";
    RegisterClass(&windowClass);

    m_Handler = CreateWindow(L"MainWindow", (LPCWSTR)m_Title, WS_POPUP | WS_CAPTION | WS_SYSMENU | WS_VISIBLE, 100, 100, m_Width, m_Height, nullptr, nullptr, nullptr, nullptr);
    if (m_Handler == 0)
    {
        MessageBox(nullptr, L"Problem with creating window!", L"Error", MB_OK);
        exit(0);
    }
}

Answer 1

Your WNDCLASS structure contains uninitialized data. Are you ignoring compiler warnings? You don't check for errors when calling RegisterClass . Quite likely that RegisterClass fails and you press on regardless.

Make sure that the WNDCLASS structure is initialized:

WNDCLASS windowClass = { 0 };

And check for errors whenever you call Win32 API functions. Here, check the value returned by RegisterClass . The documentation tells you what it means.

To your credit you did at least check the value returned by CreateWindow . But the documentation tells you that in the event of failure, call GetLastError to find out why the call failed. You did not do that? I suspect that your biggest problem is that you aren't reading the documentation in enough detail.

When you call CreateWindow , you tried to pass m_Title as the window text argument. The compiler objected with a type mismatch error. You suppressed that error with this cast:

(LPCWSTR)m_Title

Now, m_Title is const char* . It is not const wchar_t* . No amount of casting makes it so. Don't cast away type mismatch errors. Pass the correct type.

Either call CreateWindowA and pass m_Title , or change m_Title to be of type const wchar_t* . If you do the latter you'll need to pass a wide literal, L"Program" instead of "Program" .