QT TCP客户端实现

╰+哭是因爲堅強的太久メ 2022-11-12 04:25 213阅读 0赞

# 1.实现 #

QTcpSocket实例首先是通过connectToHost()尝试连接到服务器，需要指定服务器的IP地址和端口。connectToHost()是异步方式连接服务器，不会阻塞程序运行，连接后发射connected()信号。

如果需要使用阻塞方式连接服务器，则使用waitForConnected()函数阻塞程序运行，直到连接成功或失败。

与服务器建立连接后，就可以向缓冲区写数据或从接收缓冲区读取数据，实现数据的通信。当缓冲区有新数据进入时，会发射readyRead()信号，一般在此信号的槽函数里读取缓冲区数据。

# 2.示例 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d6ejk1MzIwMDQ2Mw_size_16_color_FFFFFF_t_70][]

#ifndef WIDGET_H
    #define WIDGET_H
    
    #include <QWidget>
    #include <QTcpSocket>
    
    namespace Ui {
    class Widget;
    }
    
    class Widget : public QWidget
    {
        Q_OBJECT
    
    public:
        explicit Widget(QWidget *parent = 0);
        ~Widget();
    
    private slots:
        void on_btnSend_clicked();
    
        void on_btnClear_clicked();
    
        void on_btnDisConnect_clicked();
    
        void on_btnConnect_clicked();
    
        void onConnected();
    
        void onDisConnected();
    
        void onStateChanged(QAbstractSocket::SocketState);
    
        void onReadyRead();
    
    private:
        Ui::Widget *ui;
    
        QTcpSocket *m_tcpSocket = nullptr;
    };
    
    #endif // WIDGET_H

#include "widget.h"
    #include "ui_widget.h"
    #include <QHostAddress>
    
    Widget::Widget(QWidget *parent) :
        QWidget(parent),
        ui(new Ui::Widget)
    {
        ui->setupUi(this);
    
        m_tcpSocket = new QTcpSocket(this);
        connect(m_tcpSocket,&QTcpSocket::connected,this,&Widget::onConnected);
        connect(m_tcpSocket,&QTcpSocket::disconnected,this,&Widget::onDisConnected);
        connect(m_tcpSocket,&QTcpSocket::stateChanged,this,&Widget::onStateChanged);
        connect(m_tcpSocket,&QTcpSocket::readyRead,this,&Widget::onReadyRead);
    }
    
    Widget::~Widget()
    {
        delete ui;
    }
    
    void Widget::on_btnSend_clicked()
    {
        QString msg =ui->leMsg->text();
        ui->plainTextEdit->appendPlainText("[out]"+msg);
        QByteArray str = msg.toUtf8();
        str.append('\n');
        m_tcpSocket->write(str);
    }
    
    void Widget::on_btnClear_clicked()
    {
        ui->plainTextEdit->clear();
    }
    
    void Widget::on_btnDisConnect_clicked()
    {
        if(m_tcpSocket->state() == QAbstractSocket::ConnectedState)
        {
            m_tcpSocket->disconnectFromHost();
        }
    }
    
    void Widget::on_btnConnect_clicked()
    {
        QString addr = ui->leAddr->text();
        qint16 port = ui->lePort->text().toInt();
        m_tcpSocket->connectToHost(addr,port);
    
        ui->btnConnect->setEnabled(false);
        ui->btnDisConnect->setEnabled(true);
    }
    
    void Widget::onConnected()
    {
        ui->plainTextEdit->appendPlainText("**已连接到服务器");
        ui->plainTextEdit->appendPlainText("**peer address: "+
                                 m_tcpSocket->peerAddress().toString());
        ui->plainTextEdit->appendPlainText("**peer port: "+
                                 QString::number(m_tcpSocket->peerPort()));
    }
    
    void Widget::onDisConnected()
    {
        ui->plainTextEdit->appendPlainText("**已断开服务器");
        ui->btnConnect->setEnabled(true);
        ui->btnDisConnect->setEnabled(false);
    }
    
    void Widget::onStateChanged(QAbstractSocket::SocketState)
    {
    
    }
    
    void Widget::onReadyRead()
    {
        while(m_tcpSocket->canReadLine())
        {
            ui->plainTextEdit->appendPlainText("[in] "+m_tcpSocket->readLine());
        }
    }

# 3.与服务器通信 #

![20210322212905227.gif][]

# 4.服务器实现 #

[服务器实现][Link 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d6ejk1MzIwMDQ2Mw_size_16_color_FFFFFF_t_70]: /images/20221022/cb89950df87d4ab582d57ee08895f65c.png
[20210322212905227.gif]: /images/20221022/41f8e5f9e989461f9460d6b8163eab11.png
[Link 1]: https://blog.csdn.net/wzz953200463/article/details/115099306