main.cpp

逻辑首先一个新的实例启动时将尝试连接到同一个本地服务器如果连接失败则表示第一个实例进程创建一个本地服务器否则拉起已打开的实例进程。

main.cpp

single_application.h//QT启动屏蔽cmd

#pragma

(!singleApplication.IsRunning()){MainWindow

mainWindow;mainWindow.show();singleApplication.m_mainWindow

mainWindow;return

SingleApplication::exec();}return

Created

IsRunning();private://初始化本地连接void

InitLocalConnection();//创建服务端void

ActivateWindow();public://MainWindow指针QWidget*

m_mainWindow;private://运行状态bool

m_isRunning;//是否已有实例在运行QLocalServer*

ServerQString

QDebugSingleApplication::SingleApplication(int

argc,

QFileInfo(QApplication::applicationFilePath()).fileName();qDebug()

m_serverName:

m_applicationName;InitLocalConnection();

}/***

SingleApplication::InitLocalConnection()

{m_isRunning

false;//尝试连接本地服务器如果连上了就触发OnNewConnectionQLocalSocket

socket;socket.connectToServer(m_applicationName);if

(socket.waitForConnected(m_timeout)){m_isRunning

true;return;}//首次打开exe连接不上则需要先创建一个本地服务器CreateLocalServer();

}void

SingleApplication::CreateLocalServer()

{m_localserver

QLocalServer(this);connect(m_localserver,

this,

SingleApplication::OnNewConnection);if

(!m_localserver-listen(m_applicationName)){//

QAbstractSocket::AddressInUseError){QLocalServer::removeServer(m_applicationName);m_localserver-listen(m_applicationName);

//重新监听}}

通过socket通讯实现程序单实例运行,监听到新的连接【即重新双击exe】时触发该函数.*/

void

SingleApplication::OnNewConnection()

{QLocalSocket*

m_localserver-nextPendingConnection();if

(localSocket){localSocket-waitForReadyRead(m_timeout

2);delete

localSocket;//激活窗口ActivateWindow();}

}void

SingleApplication::ActivateWindow()

{if

nullptr){m_mainWindow-raise();m_mainWindow-showNormal();m_mainWindow-activateWindow();}

}bool