QT 程序唯一性

#include "qtsingleapplication.h"

int main(int argc, char *argv[])
{
    SharedTools::QtSingleApplication a("123", argc, argv);
    if (a.isRunning())
    {
        a.sendMessage("message from other instance.");
        return 0;
    }
    widget w;

    //唯一性信号槽连接：接收到已在运行发出的信息后，发送信号messageReceived()
    QObject::connect(&a, SIGNAL(messageReceived(const QString&,QObject *)), &w, SLOT(soltMessageReceived()));

    w.show();

    return a.exec();

}

 

void widget::soltMessageReceived()
{
   this->setWindowState((this->windowState() & ~Qt::WindowMinimized) | Qt::WindowActive);
   this->setFocus(Qt::ActiveWindowFocusReason);
   QApplication::setActiveWindow(this);
}