QT网络编程

LoongServer.zip
TCP是一个基于“流”的协议

QT中建立基于TCP的连接主要是通过QTcpSocket和QTcpServer两个类实现的

一、QTcpSocket

     1.当成功建立连接时发出信号connected()

     2.当有可读数据时发出信号readyRead()

     3.当连接被终端时发出信号disconnected()

二、客户端

     1.在客户端首先定义套接字

     QTcpSocket client_tcpsocket;

     2.建立三个常用信号与槽函数的连接并实现槽函数

    connect(&client_tcpsocket,SIGNAL(connected()),this,SLOT(slot_sendRequest())); 

    connect(&client_tcpsocket,SIGNAL(readyRead()),this,SLOT(slot_getResult()));      connect(&client_tcpsocket,SIGNAL(disconnected()),this,SLOT(slot_connectionClosedByServer())); 

     3.然后尝试连接server，如果server端正在监听则会立即连接成功
    client_tcpsocket.connectToHost(QHostAddress::LocalHost,3679);

三、服务端

     1.一般是重新实现QTcpServer类

     class ManageServer : public QTcpServer

     2.建立信号与槽函数的连接并实现槽函数

     connect(&server_tcpsocket,SIGNAL(readyRead()),this,SLOT(slot_recive()));

     connect(&server_tcpsocket,SIGNAL(disconnected()),this,SLOT(deleteLater()));

     3.然后定义QTcpServer并监听端口

    ManageServer myServer; 

    if(!myServer.listen(QHostAddress::Any,3679)) 

    { 

        qDebug() << "Faile to bind to port"; 

        return 1; 

    }else      {  

        qDebug() << "Listening port 3679";      } 

四、一般先运行服务端，然后再运行客户端，这样便可成功建立连接

1.发送数据

void Thread_client::slot_sendRequest() 

{ 

 QByteArray block; 

 QDataStream out(&block,QIODevice::WriteOnly); 

 out.setVersion(QDataStream::Qt_4_8); 

 out << quint16(0) 

 << client_UserName 

 << client_PassWord; 

 out.device()->seek(0); 

 quint16 data_size = quint16(block.size() - sizeof(quint16)); 

 out << data_size; 

 client_tcpsocket.write(block); 

}

2.接收数据

void ManageServer::slot_recive()

{

 QDataStream in(&server_tcpsocket);

 in.setVersion(QDataStream::Qt_4_8);

 if(get_blocksize == 0)

 {

 if(server_tcpsocket.bytesAvailable() < sizeof(quint16))

 return;

 in >> get_blocksize;

 }

 if(server_tcpsocket.bytesAvailable() < get_blocksize)

 return;

 in >> userName;

 in >> passWord;

}

数据便已经存储在userName和passWord中了 

 

五、结果
1.运行服务端

2.运行客户端

3.服务端连接成功后