qt在动态库里面加载widget的例子

testDll和testExe项目

备注：windows下dll内不需要new QApplication, linux和mac下面需要在动态库里面new QApplication

testdll.h

#ifndef TESTDLL_H
#define TESTDLL_H

#include"testDll_global.h"

extern "C" TESTDLLSHARED_EXPORT void initApp(void);
extern "C" TESTDLLSHARED_EXPORT void showDlg(void);

extern "C" void cleanApp(void);

class QApplication;
static QApplication* shareApplication;

#endif//TESTDLL_H

testDll_global.h

#ifndef TESTDLL_GLOBAL_H
#define TESTDLL_GLOBAL_H

#include <QtCore/qglobal.h>

#if defined(TESTDLL_LIBRARY)
#  define TESTDLLSHARED_EXPORT Q_DECL_EXPORT
#else
#  define TESTDLLSHARED_EXPORT Q_DECL_IMPORT
#endif

#endif // TESTDLL_GLOBAL_H

testdll.cpp

#include<QApplication>
#include<QMessageBox>
#include"TestDll.h"
#include"Form.h"

extern "C" TESTDLLSHARED_EXPORT void initApp(void)
{
    shareApplication=NULL;
}

extern "C" TESTDLLSHARED_EXPORT void showDlg(void)
{
    if( NULL == shareApplication )
    {
        int argc=0;

        //windows下注释掉
//        shareApplication = new QApplication(argc,NULL);

        Form* pForm=new Form;
        pForm->show();

//        shareApplication->exec();
    }
}

extern "C" void cleanApp(void)
{
    if( NULL != shareApplication )
    {
        QMessageBox::information(NULL,"","appdestroyed",0);

//        shareApplication->quit();
//        shareApplication=NULL;
    }
}

testExe的测试cpp里面

void MainWindow::on_pushButton_clicked()
{
    QLibrary dll("testDll");

    if( !dll.load() ) return;

    typedef void(*DLL_INIT_APP)();
    typedef void(*DLL_SHOW_DLG)();

    DLL_INIT_APP dll_initApp = (DLL_INIT_APP)dll.resolve("initApp");

    DLL_SHOW_DLG dll_showDlg= (DLL_SHOW_DLG)dll.resolve("showDlg");

    dll_initApp();
    dll_showDlg();
}