49.Qt-网络编程之QTCPSocket和QTCPServer(实现简易网络调试助手)

8.9更新说明

如下图所示,支持十六进制收发,下载地址已经更新.源码下载地址:https://download.csdn.net/download/qq_37997682/11504836

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在上章 48.QT-网络通信讲解1,我们学习了网络通信基础后,本章便来实战一篇.

PS:支持客户端和服务器,提供源码,并且服务器支持多客户端连入,并且可以指定与个别客户端发送数据,也可以给所有连入的客户端发送数据.

1.效果图所下所示:

如下图所示,当服务器状态下,如果有客户端连入,会提示客户端信息:

2.效果操作

客户端操作:

服务器操作:

从上面操作可以看出,服务器支持多客户端连入,并且可以指定与个别客户端发送数据,也可以给所有连入的客户端发送数据.

3.首先创建UI

4.注意事项

不管是服务器还是客户端,都可以通过peerAddress()和peerPort()来获取目标地址和目标端口

4.1服务器监听时

比如服务器,则可以通过QTcpSocket的peerAddress()则可以获取连入的客户端地址

也可以通过children()来获取所有连入的客户端(需要注意的是也会获取到服务器本身的tcp地址和端口),示例如下:

QList<QTcpSocket *> m_tcps = m_server.findChildren<QTcpSocket *>();
foreach (QTcpSocket *tcp, m_tcps)
{
        qDebug() << "Address:" << tcp->peerAddress ();
        qDebug() << "Port:" << tcp->peerPort  ();
}

如果我们只向连入的客户端某个端口发送数据时,就可以通过上面的方式筛选出来.

这样做的话如果觉得很麻烦,也可以将之前连接上的客户端存到QList里再进行筛选.

4.2 QTcpSocket步骤

• 首先通过connectToHost()来连接服务器.
• 然后调用waitForConnected()来判断是否连接服务器超时
• 当我们接收到服务器数据的时候,则会发出readyRead()信号,然后再进行read ()读取发来的数据
• 发送数据时,则调用write()函数进行发送,当bytesWritten()信号函数触发时,便可以获取成功发送的数据长度.

注意:如果read到的数据长度量不是自己想要的,此时我们便可以通过bytesAvailable()来读取接收到的数据长度量.当达到多少时,再进行read ()读取.

4.3 QTcpServer步骤

• 首先通过listen(QHostAddress::AnyIPv4, port)来监听所有来自IPV4的客户端
• 当有新的客户端连接服务器的时候,会自动触发newConnection()信号函数,然后我们可以通过通过QTcpSocket * nextPendingConnection()成员函数来获取当前连接上的新的客户端类.然后再对QTcpSocket来进行信号槽绑定
• 当客户端发来数据的时候,则可以通过我们定义的onServerDataReady()来读取数据
• 当我们向某个连接的客户端发送数据时,则通过m_server.findChildren()来筛选出来,然后write即可.

5.代码介绍

5.1  头文件介绍

#ifndef WIDGET_H
#define WIDGET_H
 
#include <QWidget>
#include <QTcpSocket>
#include <QTcpServer>
#include <QMessageBox>
 
namespace Ui {
class Widget;
}
 
class Widget : public QWidget
{
    Q_OBJECT
 
    QTcpSocket m_client;
    QTcpServer m_server;
    QString targetAddr;
    int targetPort;
public:
    explicit Widget(QWidget *parent = );
    ~Widget();
private slots:
    void on_btn_switch_clicked();
    void on_tcpMode_currentIndexChanged(int index);
    void on_btn_send_clicked();             //发送按钮
    void on_betn_clear_clicked();           //清空按钮
 
    //客户端槽函数
    void onClientConnected();
    void onClientDisconnected();
    void onClientDataReady();
    void onClientBytesWritten(qint64 bytes);
    void onClientErr(QAbstractSocket::SocketError socketError);
 
    //服务器槽函数
    void onServerNewConnection();
    void onServerConnected();
    void onServerDisconnected();
    void onServerDataReady();
    void onServerBytesWritten(qint64 bytes);
private:
    void startConnect(bool ison);
 
    void initClientSignals();   //初始化客户端信号槽
    bool startClient();         //启动客户端
 
    void initServerSignals();   //初始化客户端信号槽
    bool startServer();     //启动服务器
 
    Ui::Widget *ui;
};
 
#endif // WIDGET_H

5.2  widget.cpp介绍

该cpp主要是用来处理界面操作的函数

#include "widget.h"
#include "ui_widget.h"
 
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    startConnect(false);
    on_tcpMode_currentIndexChanged();
    initClientSignals();        //初始化客户端信号槽
    initServerSignals();        //初始化服务器信号槽
 
    //限制只能数字输入
    QRegExp regx("[0-9]+$");
    QValidator *validator = new QRegExpValidator(regx, this );
    ui->ipAddr1->setValidator( validator );
    ui->ipAddr2->setValidator( validator );
    ui->ipAddr3->setValidator( validator );
    ui->ipAddr4->setValidator( validator );
    ui->ipPort->setValidator( validator );
}
void Widget::on_tcpMode_currentIndexChanged(int index)
{
    if(index==)        //clent
    {
        ui->ipPortLabel->setText("服务器端口号:");
        ui->ipAddLabel->show();
        ui->ipAdds->show();
        ui->targetLabel->hide();
        ui->targetObject->hide();
    }
    else
    {
        ui->ipAddLabel->hide();
        ui->ipAdds->hide();
        ui->ipPortLabel->setText("本地端口号:");
    }
}
 
void Widget::on_btn_switch_clicked()        //切换连接开关
{
    bool ret;
    if(ui->btn_switch->text()=="打开连接")
    {
        if(ui->tcpMode->currentIndex()==)  //启动客户端
           ret=startClient() ;
        else
            ret=startServer();
        if(ret)
            startConnect(true);
    }
    else
    {
        if(ui->tcpMode->currentIndex()==)  //启动客户端
          m_client.close();
        else
        {
            if( m_server.isListening() )
            {
                QList<QTcpSocket *> m_tcps = m_server.findChildren<QTcpSocket *>();
                foreach (QTcpSocket *tcp, m_tcps)
                {
                    tcp->close();
                }
                m_server.close();
            }
        }
        startConnect(false);
    }
}
 
void Widget::startConnect(bool ison)
{
    if(!ison)
    {
        ui->btn_switch->setStyleSheet("color:blue;border: 1px solid blue");
        ui->btn_switch->setText("打开连接");
 
        //使能
        ui->ipAddr1->setEnabled(true);
        ui->ipAddr2->setEnabled(true);
        ui->ipAddr3->setEnabled(true);
        ui->ipAddr4->setEnabled(true);
        ui->tcpMode->setEnabled(true);
        ui->ipPort->setEnabled(true);
        ui->localPort->setText("");
    }
    else
    {
        ui->btn_switch->setStyleSheet("color:red;border: 1px solid red");
        ui->btn_switch->setText("关闭连接");
        //失能
        ui->ipAddr1->setEnabled(false);
        ui->ipAddr2->setEnabled(false);
        ui->ipAddr3->setEnabled(false);
        ui->ipAddr4->setEnabled(false);
        ui->tcpMode->setEnabled(false);
        ui->ipPort->setEnabled(false);
        targetAddr="";
        targetPort=;
        ui->sendLenLabel->setText("");
    }
}
 
void Widget::on_betn_clear_clicked()
{
   ui->recvEdit->clear();
   targetAddr="";
   targetPort=;
}
 
void Widget::on_btn_send_clicked()
{
    if(ui->btn_switch->text()!="打开连接")
    {
        if(ui->tcpMode->currentIndex()==)  //客户端
        {
            m_client.write(ui->sendEdit->toPlainText().toLocal8Bit(),ui->sendEdit->toPlainText().toLocal8Bit().length());
        }
        else
        {
            if(ui->targetObject->currentText()!="所有对象")
            {
                QList<QTcpSocket *> m_tcps = m_server.findChildren<QTcpSocket *>();
                foreach (QTcpSocket *tcp, m_tcps)
                {
                    if(ui->targetObject->currentText() == tcp->objectName())
                    {
                        tcp->write(ui->sendEdit->toPlainText().toLocal8Bit(),ui->sendEdit->toPlainText().toLocal8Bit().length());
                        break;
                    }
                }
            }
            else            //所有连接上的客户端都发送一遍
            {
                QList<QTcpSocket *> m_tcps = m_server.findChildren<QTcpSocket *>();
                foreach (QTcpSocket *tcp, m_tcps)
                {
                    tcp->write(ui->sendEdit->toPlainText().toLocal8Bit(),ui->sendEdit->toPlainText().toLocal8Bit().length());
                }
            }
        }
    }
}
 
Widget::~Widget()
{
    QList<QTcpSocket *> m_tcps = m_server.findChildren<QTcpSocket *>();
    foreach (QTcpSocket *tcp, m_tcps)
    {
        tcp->close();
    }
    if(m_client.isOpen())
    {
        m_client.close();
         qDebug()<<"m_client close";
    }
    delete ui;
}

5.3 clentHandler.cpp介绍

该cpp主要用来处理客户端操作相关的文件.

#include "widget.h"
#include "ui_widget.h"
 
void Widget::initClientSignals()  //初始化客户端信号槽
{
    connect(&m_client, SIGNAL(connected()), this, SLOT(onClientConnected()));
    connect(&m_client, SIGNAL(disconnected()), this, SLOT(onClientDisconnected()));
    connect(&m_client, SIGNAL(readyRead()), this, SLOT(onClientDataReady()));
    connect(&m_client, SIGNAL(bytesWritten(qint64)), this, SLOT(onClientBytesWritten(qint64)));
    connect(&m_client, SIGNAL(error(QAbstractSocket::SocketError )), this, SLOT(onClientErr(QAbstractSocket::SocketError)));
}
bool Widget::startClient()         //启动客户端
{
    QString ip = QString("%1.%2.%3.%4").arg(ui->ipAddr1->text()).arg(ui->ipAddr2->text()).arg(ui->ipAddr3->text()).arg(ui->ipAddr4->text());
    qDebug()<<ip;
    m_client.connectToHost(ip, ui->ipPort->text().toInt());
    if(m_client.waitForConnected())
    {
        return true;
    }
    else
    {
        QMessageBox::information(this,"提示",QString("连接超时"),QMessageBox::Ok);
        return false;
    }
}
 
void Widget::onClientConnected()
{
    startConnect(true);
    QMessageBox::information(this,"提示","连接成功",QMessageBox::Ok);
    ui->localPort->setText(QString("%1").arg(m_client.localPort())); //显示本地端口号
}
void Widget::onClientDisconnected()
{
    startConnect(false);
    QMessageBox::information(this,"提示","断开完成",QMessageBox::Ok);
}
void Widget::onClientDataReady()
{
    if(m_client.peerAddress().toString()!=targetAddr || m_client.peerPort()!=targetPort  )
    {
        targetAddr = m_client.peerAddress().toString();
        targetPort = m_client.peerPort();
        ui->recvEdit->insertPlainText("[接受来自"+ targetAddr+":"+QString("%1").arg(targetPort)+"]:\r\n");
    }
    ui->recvEdit->moveCursor(QTextCursor::End);
    ui->recvEdit->insertPlainText(QString::fromLocal8Bit(m_client.readAll())+"\r\n");
}
void Widget::onClientBytesWritten(qint64 bytes)
{
    qDebug() << "onBytesWritten:" << bytes;
    ui->sendLenLabel->setText(QString("%1").arg(ui->sendLenLabel->text().toInt()+bytes));
}
 
void  Widget::onClientErr(QAbstractSocket::SocketError socketError)
{
    qDebug()<<"onClientErr:"<<socketError;
    m_client.close();
    startConnect(false);
    QMessageBox::information(this,"提示",QString("连接失败:%1").arg((int)socketError),QMessageBox::Ok);
}

5.4 serverHandler.cpp介绍

该cpp主要用来处理服务器操作相关的文件

#include "widget.h"
#include "ui_widget.h"
 
void Widget::initServerSignals()   //初始化信号槽
{
    connect(&m_server, SIGNAL(newConnection()), this, SLOT(onServerNewConnection()));
}
bool Widget::startServer()         //启动服务器
{
    if(m_server.listen(QHostAddress::AnyIPv4,ui->ipPort->text().toInt()))       //只监听IPV4的所有客户端
    {
        ui->targetLabel->show();
        ui->targetObject->show();
        ui->localPort->setText(QString("%1").arg(m_server.serverPort()));
        return true;
    }
    else
       return false;
}
void Widget::onServerNewConnection()
{
    qDebug() << "onNewConnection";
    QTcpSocket* tcp = m_server.nextPendingConnection();     //获取新的客户端信息
    QString info=tcp->peerAddress().toString()+":"+QString("%1").arg(tcp->peerPort());
    ui->targetObject->addItem(info);
    QMessageBox::information(this,"提示",QString("新的客户端连入:%1").arg(info),QMessageBox::Ok);
    tcp->setObjectName(info);       //设置名称,方便查找
    connect(tcp, SIGNAL(connected()), this, SLOT(onServerConnected()));
    connect(tcp, SIGNAL(disconnected()), this, SLOT(onServerDisconnected()));
    connect(tcp, SIGNAL(readyRead()), this, SLOT(onServerDataReady()));
    connect(tcp, SIGNAL(bytesWritten(qint64)), this, SLOT(onServerBytesWritten(qint64)));
}
void Widget::onServerConnected()
{
 
}
 
void Widget::onServerDisconnected()
{
    QTcpSocket* tcp = dynamic_cast<QTcpSocket*>(sender());
    if( tcp != NULL )       //从连接对象中移除掉
    {
        qDebug() << "onServerDisconnected";
        qDebug() << "Local Address:" << tcp->peerAddress();
        qDebug() << "Local Port:" << tcp->peerPort();
        QString info=tcp->peerAddress().toString()+":"+QString("%1").arg(tcp->peerPort());
        QMessageBox::information(this,"提示",QString("客户端断开连接:%1").arg(info),QMessageBox::Ok);
 
        int index = ui-> targetObject ->findText(info);
        if(index>=)
        ui->targetObject->removeItem(index);
    }
}
void Widget::onServerDataReady()
{
    QTcpSocket* tcp = dynamic_cast<QTcpSocket*>(sender());
    if(tcp->peerAddress().toString()!=targetAddr || tcp->peerPort()!=targetPort  )
    {
        targetAddr = tcp->peerAddress().toString();
        targetPort = tcp->peerPort();
        ui->recvEdit->insertPlainText("[接受来自"+ targetAddr+":"+QString("%1").arg(targetPort)+"]:\r\n");
    }
    ui->recvEdit->moveCursor(QTextCursor::End);
    ui->recvEdit->insertPlainText(QString::fromLocal8Bit(tcp->readAll())+"\r\n");
}
void Widget::onServerBytesWritten(qint64 bytes)
{
    qDebug() << "onBytesWritten:" << bytes;
    ui->sendLenLabel->setText(QString("%1").arg(ui->sendLenLabel->text().toInt()+bytes));
}