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

 1 #ifndef TESTDLL_H
 2 #define TESTDLL_H
 3 
 4 #include"testDll_global.h"
 5 
 6 extern "C" TESTDLLSHARED_EXPORT void initApp(void);
 7 extern "C" TESTDLLSHARED_EXPORT void showDlg(void);
 8 
 9 extern "C" void cleanApp(void);
10 
11 class QApplication;
12 static QApplication* shareApplication;
13 
14 #endif//TESTDLL_H

testDll_global.h

 1 #ifndef TESTDLL_GLOBAL_H
 2 #define TESTDLL_GLOBAL_H
 3 
 4 #include <QtCore/qglobal.h>
 5 
 6 #if defined(TESTDLL_LIBRARY)
 7 #  define TESTDLLSHARED_EXPORT Q_DECL_EXPORT
 8 #else
 9 #  define TESTDLLSHARED_EXPORT Q_DECL_IMPORT
10 #endif
11 
12 #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

 1 void MainWindow::on_pushButton_clicked()
 2 {
 3     QLibrary dll("testDll");
 4 
 5     if( !dll.load() ) return;
 6 
 7     typedef void(*DLL_INIT_APP)();
 8     typedef void(*DLL_SHOW_DLG)();
 9 
10     DLL_INIT_APP dll_initApp = (DLL_INIT_APP)dll.resolve("initApp");
11 
12     DLL_SHOW_DLG dll_showDlg= (DLL_SHOW_DLG)dll.resolve("showDlg");
13 
14     dll_initApp();
15     dll_showDlg();
16 }