外部程序只运行一个实例的方法

connect(Process, &QProcess::stateChanged, [=](const QProcess::ProcessState newState)
        {
            //如果运行状态变成NotRunning，关闭Process.
            if (newState == QProcess::NotRunning)
            {
                Process->close();
            }
        });

//打开外部软件
connect(ui.actionSetBoard, &QAction::triggered, [=]()
        {
            const QStringList arguments;
            //已打开，直接返回。只允许一个软件运行
            if (Process->isOpen())
                return;

            Process->setProcessChannelMode(QProcess::MergedChannels);
            Process->start("./***.exe", arguments);
        });