I am new to win32 C++ app . Even you can say I have never done any coding in win32 .Now I am trying to create win32 app , which will use webview2 to launch browser , do some authentication , and fetch token . Here , once I fetched my token in add_WebResourceResponseReceived , I am closing the browser window from my code . but it crashes in DispatchMessage.Here is my code ,

void CloseBrowserAndCleanup(HWND _hWnd);

__MIDL_DECLSPEC_DLLEXPORT int getTokenFromWebView2()
{
    std::wstring authToken;

    WNDCLASSEX wcex;
    HINSTANCE hInstance = GetModuleHandle(NULL);
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(hInstance, IDI_APPLICATION);
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = szWindowClass;
    wcex.hIconSm = LoadIcon(wcex.hInstance, IDI_APPLICATION);

    if (!RegisterClassEx(&wcex))
    {
        MessageBox(NULL,
            _T("Call to RegisterClassEx failed!"),
            _T("Windows Desktop Guided Tour"),
            NULL);

        return 1;
    }

    // Store instance handle in our global variable
    hInst = hInstance;

    HWND hWnd = CreateWindow(
        szWindowClass,
        szTitle,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT,
        1200, 900,
        NULL,
        NULL,
        hInstance,
        NULL
    );

    if (!hWnd)
    {
        MessageBox(NULL,
            _T("Call to CreateWindow failed!"),
            _T("Windows Desktop Guided Tour"),
            NULL);

        return 1;
    }

    // The parameters to ShowWindow explained:
    // hWnd: the value returned from CreateWindow
    // nCmdShow: the fourth parameter from WinMain
    ShowWindow(hWnd,
        SW_SHOW);
    UpdateWindow(hWnd);

//  CreateConsole();


    // <-- WebView2 sample code starts here -->

    HRESULT hr = CreateCoreWebView2EnvironmentWithOptions(nullptr, L"D:\webview2", nullptr,
        Callback<ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler>(
            [hWnd, &authToken](HRESULT result, ICoreWebView2Environment* env) -> HRESULT {

                // Create a CoreWebView2Controller and get the associated CoreWebView2 whose parent is the main window hWnd
                env->CreateCoreWebView2Controller(hWnd, Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
                    [hWnd, &authToken](HRESULT result, ICoreWebView2Controller* controller) -> HRESULT {
                        if (controller != nullptr) {
                            webviewController = controller;
                            webviewController->get_CoreWebView2(&webview);
                        }

                        wil::com_ptr<ICoreWebView2Settings> settings;
                        webview->get_Settings(&settings);
                        settings->put_IsScriptEnabled(TRUE);
                        settings->put_AreDefaultScriptDialogsEnabled(TRUE);
                        settings->put_IsWebMessageEnabled(TRUE);

                        RECT bounds;
                        GetClientRect(hWnd, &bounds);
                        webviewController->put_Bounds(bounds);

                        webview->Navigate(L"my url");
                        
                        EventRegistrationToken token;                       

                        if (auto webView10 = webview.try_query<ICoreWebView2_10>())
                        {

                            webView10->add_WebResourceRequested(Callback<ICoreWebView2WebResourceRequestedEventHandler>(
                                [](ICoreWebView2* sender, ICoreWebView2WebResourceRequestedEventArgs* args) -> HRESULT {
                                    wil::com_ptr<ICoreWebView2WebResourceRequest> request;
                                    args->get_Request(&request);

                                    wil::com_ptr<ICoreWebView2HttpRequestHeaders> requestHeaders;
                                    request->get_Headers(&requestHeaders);

                                    RequestHeadersToJsonString(requestHeaders.get());

                                    return S_OK;
                                }).Get(), nullptr);
                            webView10->add_WebResourceResponseReceived(Callback<ICoreWebView2WebResourceResponseReceivedEventHandler>(
                                [hWnd, &authToken](ICoreWebView2* webView , ICoreWebView2WebResourceResponseReceivedEventArgs* args)->HRESULT {
                                    wil::com_ptr<ICoreWebView2WebResourceRequest> request;

                                    CheckFailure(args->get_Request(&request));

                                    wil::unique_cotaskmem_string uri;
                                    CheckFailure(request->get_Uri(&uri));
                                    std::wcout << "response uri : " << uri.get() << std::endl;
                                    if (wcscmp(uri.get(), L"my auth url/"))
                                    {
                                        wil::com_ptr<ICoreWebView2HttpRequestHeaders> requestHeaders;
                                        CheckFailure(request->get_Headers(&requestHeaders));
                                        wil::unique_cotaskmem_string authHeaderValue;
                                        if (requestHeaders->GetHeader(L"Authorization", &authHeaderValue) == S_OK)
                                        {
                                            authToken = authHeaderValue.get();
                                            CloseBrowserAndCleanup(hWnd);   
                                           //***once above call is completed it crashing in `DispatchMessage(&msg)` line .                                      
                                        }
                                    }                                   
                                    return S_OK;
                                }
                            ).Get(), &token);

                        }
                        else {
                            FeatureNotAvailable();
                        }

                        return S_OK;
                    }).Get());
                return S_OK;
            }).Get());
    
    // <-- WebView2 sample code ends here -->

    // Main message loop:
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
            TranslateMessage(&msg);
            DispatchMessage(&msg); // it is crashing here after calling `CloseBrowserAndCleanup(hWnd);`
    }

    //return (int)msg.wParam;
    return 1; 
}

void CloseBrowserAndCleanup(HWND _hWnd) {
    if (!cleanupStarted)
    {
        cleanupStarted = true;
        if (webviewController) {
            webviewController->Close();
            webviewController = nullptr;
        }
        if (webview) {
            webview = nullptr;
        }
        if (_hWnd) {
            DestroyWindow(_hWnd);
            _hWnd = nullptr;
        }

        PostQuitMessage(0);
    }
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    TCHAR greeting[] = _T("Hello, Windows desktop!");

    switch (message)
    {
    case WM_SIZE:
        if (webviewController != nullptr) {
            RECT bounds;
            GetClientRect(hWnd, &bounds);
            webviewController->put_Bounds(bounds);
        };
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
        break;
    }

    return 0;
}