QLocalServer和QLocalSocket单进程和进程通信实例_F_hawk189_新浪博客

参考博客：http://tgstdj.blog.163.com/blog/static/74820040201243072238780/

1. 建立一个QLocalServer实例 m_server2. 进行listen :

m_server->listen("servername")

3. 当有连接到来时,QLocalServer会发送netConnection()信号,所以进行信号连接, 在init()函数中:

connect(m_server, SIGNAL(newConnection()), this, SLOT(newConnection()));

4.在newConnection()函数中取得连接客户端的QLocalSocket

QLocalSocket *newsocket = m_server->nextPendingConnection();

5.当QLocalSocket可以读数据时它会发送readyRead()信号,所以对newsocket进行信号连接, 在newConnection()函数中:

 connect(newsocket, SIGNAL(readyRead()), this, SLOT(readyRead()));

6.在readyRead()函数中读取数据:

// 取得是哪个localsocket可以读数据了

QLocalSocket *local = static_cast(sender());

if (!local)

return;

QTextStream in(local);

QString readMsg;

// 读出数据

readMsg = in.readAll();

全部代码, QT新建一个项目，主窗口mainwindow。

server.h:(尖括号替换为了引号，因为新浪里尖括号无法直接打出)

#ifndef SERVER_H

#define SERVER_H

#include "QObject"

#include "QtNetwork/QLocalServer"

#include "QtNetwork/QLocalSocket"

#include "QString"

#include "QTextStream"

class Server : public QObject

{

Q_OBJECT

public:

explicit Server(QObject *parent = 0);

~Server();

int init(const QString & servername);

private:

int isServerRun(const QString & servername);

QLocalServer *m_server;

signals:

void newMessage(const QString &msg);

public slots:

void newConnection();

void readyRead();

};

#endif // SERVER_H

server.cpp:

#include "server.h"

 

Server::Server(QObject *parent) :

 QObject(parent)

{

 m_server = 0;

}

 

Server::~Server()

{

 if (m_server)

  delete m_server;

}

int Server::init(const QString &servername)

{

 //已经有实例在运行，返回0

 if (isServerRun(servername))

 return 0;

  m_server = new QLocalServer;

//先移除原来存在的，如果不移除，如果 //servername已经存在就会listen失败       QLocalServer::removeServer(servername);

//监听

 m_server->listen(servername);                  connect(m_server,SIGNAL(newConnection()),this,SLOT(newConnection()));

 return 1;

}

 

void Server::newConnection()

{

//有新连接来了

 QLocalSocket *newsocket = m_server->nextPendingConnection(); connect(newsocket,SIGNAL(readyRead()),this,SLOT(readyRead()));

}

void Server::readyRead()

{

//取得是哪个localsocket可以读数据了

 QLocalSocket *local = static_cast(sender());

 if (!local)

 return ;

QTextStream in(local);

 QString readMsg;

 //读出数据

 readMsg = in.readAll();

 //发送收到数据信号

 emit newMessage(readMsg);

}

int Server::isServerRun(const QString &servername)

{

//判断是否有一个同名的服务器在运行

 QLocalSocket ls;

 ls.connectToServer(servername);

if (ls.waitForConnected(1000))

{

//已经在运行

 ls.disconnectFromServer()

; ls.close();

 return 1;

}

return 0;

}

main.cpp:

#include "mainwindow.h"

#include "QApplication"

#include "QLabel"

#include "QMessageBox"

#include "server.h"

#include "QObject"

 

int main(int argc, char *argv[])

{

 QApplication a(argc, argv);

QLabel text("test");

 Server s;

 if (!s.init("localserver-test"))

 {

//初始化失败，说明已经有一个服务在运行

 QMessageBox::information(&text,"info","There is already exist one!");

 return 1;

 }

 

QObject::connect(&s,SIGNAL(newMessage(const QString &)),&text,SLOT(setText(const QString &))); text.show();

 

return a.exec();

}

工程结构：

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客户端测试：

main.cpp:

#include "mainwindow.h"
#include "QApplication"
#include "QtNetwork/QLocalSocket"
#include "stdlib.h"
#include "unistd.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QLocalSocket ls;
    ls.connectToServer("localserver-test");
    srand(1000);
    if (ls.waitForConnected())
    {
        while(1)
        {
            QTextStream ts(&ls);
            ts<<QString::number(rand()) + "\nTTTTTTTTTTT" + "\nXXXXXXXXXXX";
            ts.flush();
            ls.waitForBytesWritten();
            sleep(1);
        }
    }
    MainWindow w;
    w.show();

    return a.exec();
}