win32 dll 调用qt窗口

#include <qwinwidget.h>
#include <QHBoxLayout>
#include <windows.h>
#include "widget.h"

BOOL WINAPI DllMain( HINSTANCE hInstance, DWORD dwReason, LPVOID /*lpvReserved*/ )
{
    static bool ownApplication = FALSE;

    if ( dwReason == DLL_PROCESS_ATTACH ){
        ownApplication = QMfcApp::pluginInstance( hInstance );
    }
    else if ( dwReason == DLL_PROCESS_DETACH && ownApplication ){
        qApp->quit();
        delete qApp;
    }

    return TRUE;
}

extern "C" __declspec(dllexport) int ShowDialog(HWND parent)
{
    QWinWidget win( parent );
    win.showCentered();
    win.center();

    QHBoxLayout hbox(&win);
    Widget *w = new Widget(&win);
    w->setWindowFlag(Qt::Window);
    hbox.addWidget(w);

    win.show();
    return qApp->exec();
}

调用：

        typedef int(*FUNC)(HWND);
        HMODULE hDll = LoadLibrary(L"qtdialog.dll");
        if (hDll!=NULL) {
            FUNC displayQML = (FUNC)GetProcAddress(hDll, "ShowDialog");

            if (displayQML != NULL) {
                displayQML(hWnd);
            }
            else {
                MessageBox(NULL, L"can't found function", L"tips", MB_OK);
            }
            FreeLibrary(hDll);
        }
        else {
            MessageBox(NULL, L"can't found dll.", L"tips", MB_OK);
        }

模态：this->setWindowModality(Qt::WindowModal);