c++ - WIN32 :C++, 为什么在WM_CLOSE上调用Messagebox函数 程序死机

Question

我正在学习如何使用 Visual C++ 创建 Windows 桌面应用程序。
我正在创建一个什么都不做的简单窗口，当我按下关闭按钮时，我想显示一个消息框以确认我真的想在关闭窗口之前关闭它。
因此，当我收到 WM_CLOSE 消息时，我尝试使用 Messagebox 函数执行此操作，但由于某种原因，程序卡住并且无法关闭。
对不起，有人可以帮我吗？
来源如下。感谢您的帮助。

#include<Windows.h>

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
ATOM InitApp(HINSTANCE);
BOOL InitInstance(HINSTANCE, int);

TCHAR szClassName[] = TEXT("winapp");       

int WINAPI WinMain(HINSTANCE hCurInst, HINSTANCE hPrevInst, LPSTR lpsCmdLine, int nCmdShow) {                                                       
    MSG msg;
    BOOL bRet;
    if(!InitApp(hCurInst))
        return FALSE;
    if (!InitInstance(hCurInst, nCmdShow))
        return FALSE;
    while ((bRet = GetMessage(&msg, NULL, 0, 0)) != 0) {
        if (bRet == -1) {
            MessageBox(NULL, TEXT("GetMessageエラー"), TEXT("Error"), MB_OK);
            break;
        }
        else {
            TranslateMessage(&msg);
            DispatchMessageW(&msg);
        }
    }
    return (int)msg.wParam;
}

ATOM InitApp(HINSTANCE hInst) {
    WNDCLASSEX wc;
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;     
    wc.lpfnWndProc = WndProc;   
    wc.cbClsExtra = 0;      
    wc.cbWndExtra = 0;                  
    wc.hInstance = hInst;               
    wc.hIcon = (HICON)LoadImage(                
        NULL,                                   
        MAKEINTRESOURCE(IDI_APPLICATION),   
        IMAGE_ICON,                             
        0,                                          
        0,                                  
        LR_DEFAULTSIZE | LR_SHARED);            
    wc.hCursor = (HCURSOR)LoadImage(        
        NULL,           
        MAKEINTRESOURCE(IDC_ARROW),                 
        IMAGE_CURSOR, 
        0, 
        0,
        LR_DEFAULTSIZE | LR_SHARED);        
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH); 
    wc.lpszMenuName = NULL;                     
    wc.lpszClassName = szClassName;             
    wc.hIconSm = (HICON)LoadImage(                  
        NULL,
        MAKEINTRESOURCE(IDI_APPLICATION), 
        IMAGE_ICON,
        0, 
        0, 
        LR_DEFAULTSIZE | LR_SHARED);

    return (RegisterClassEx(&wc));
}

BOOL InitInstance(HINSTANCE hInst, int nCmdShow) {
    HWND hWnd;                          
    hWnd = CreateWindow(
        szClassName,                    
        TEXT("Winapp"),                     
        WS_OVERLAPPEDWINDOW,            
        CW_USEDEFAULT,                  
        CW_USEDEFAULT,  
        CW_USEDEFAULT,      
        CW_USEDEFAULT,      
        NULL,                   
        NULL,                       
        hInst,          
        NULL);
    if (!hWnd)
        return FALSE;
    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);
    return TRUE;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {
    int id;

    switch (msg){
    case WM_CLOSE:
        id = MessageBox(hWnd,TEXT("終了してもよろしいですか？"),TEXT("終了確認"),MB_YESNO | MB_ICONQUESTION);
        if(id==IDYES){
            DestroyWindow(hWnd);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return (DefWindowProc(hWnd, msg, wp, lp));
    }
    return 0;
}

Answer 1

尝试在程序中明确使用 unicode。例如使用 MessageBoxW 而不是 MessageBox 和 L"终了してもよろしいですか？"而不是 TEXT("终了してもよろしいですか？") 并稍微更改您的 windowproc:

#include<Windows.h>

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
ATOM InitApp(HINSTANCE);
BOOL InitInstance(HINSTANCE, int);

TCHAR szClassName[] = TEXT("winapp");       

int WINAPI WinMain(HINSTANCE hCurInst, HINSTANCE hPrevInst, LPSTR lpsCmdLine, int nCmdShow) {                                                       
    MSG msg;
    BOOL bRet;
    if(!InitApp(hCurInst))
        return FALSE;
    if (!InitInstance(hCurInst, nCmdShow))
        return FALSE;
    while ((bRet = GetMessage(&msg, NULL, 0, 0)) != 0) {
        if (bRet == -1) {
            MessageBoxW(NULL, L"GetMessageエラー", L"Error", MB_OK);
            break;
        }
        else {
            TranslateMessage(&msg);
            DispatchMessageW(&msg);
        }
    }
    return (int)msg.wParam;
}

ATOM InitApp(HINSTANCE hInst) {
    WNDCLASSEX wc;
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;     
    wc.lpfnWndProc = WndProc;   
    wc.cbClsExtra = 0;      
    wc.cbWndExtra = 0;                  
    wc.hInstance = hInst;               
    wc.hIcon = (HICON)LoadImage(                
        NULL,                                   
        MAKEINTRESOURCE(IDI_APPLICATION),   
        IMAGE_ICON,                             
        0,                                          
        0,                                  
        LR_DEFAULTSIZE | LR_SHARED);            
    wc.hCursor = (HCURSOR)LoadImage(        
        NULL,           
        MAKEINTRESOURCE(IDC_ARROW),                 
        IMAGE_CURSOR, 
        0, 
        0,
        LR_DEFAULTSIZE | LR_SHARED);        
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH); 
    wc.lpszMenuName = NULL;                     
    wc.lpszClassName = szClassName;             
    wc.hIconSm = (HICON)LoadImage(                  
        NULL,
        MAKEINTRESOURCE(IDI_APPLICATION), 
        IMAGE_ICON,
        0, 
        0, 
        LR_DEFAULTSIZE | LR_SHARED);

    return (RegisterClassEx(&wc));
}

BOOL InitInstance(HINSTANCE hInst, int nCmdShow) {
    HWND hWnd;                          
    hWnd = CreateWindow(
        szClassName,                    
        TEXT("Winapp"),                     
        WS_OVERLAPPEDWINDOW,            
        CW_USEDEFAULT,                  
        CW_USEDEFAULT,  
        CW_USEDEFAULT,      
        CW_USEDEFAULT,      
        NULL,                   
        NULL,                       
        hInst,          
        NULL);
    if (!hWnd)
        return FALSE;
    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);
    return TRUE;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {
    int id;

    switch (msg){
    case WM_CLOSE:
        id = MessageBoxW(hWnd,L"終了してもよろしいですか？", L"終了確認",MB_YESNO | MB_ICONQUESTION);
        if(id==IDYES){
            DestroyWindow(hWnd);
        }
        return 0;
        

    case WM_DESTROY:
        PostQuitMessage(0);
        break;
        
    }
    return (DefWindowProc(hWnd, msg, wp, lp));
}