qt_host/mainwindow.cpp

#include "mainwindow.h"
#include "./ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    ui->le_port->setText("1234");

    connect(ui->bt_start, &QPushButton::clicked, this, &MainWindow::start_server);
    connect(ui->bt_stop, &QPushButton::clicked, this, &MainWindow::stop_server);
    client = nullptr;
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::start_server()
{
    int port = ui->le_port->text().toInt();
    if (port == 0)
    {
        return;
    }
    server.listen(QHostAddress::Any, port);
    ui->lb_state->setText("启动成功");
    ui->lb_listen_port->setText(QString::number(port));
    connect(&server, &QTcpServer::newConnection, this, &MainWindow::new_connection);
}

void MainWindow::stop_server()
{
    server.close();
    ui->lb_state->setText("已停止");
    ui->lb_listen_port->setText("");
}
void MainWindow::new_connection()
{
    if (server.hasPendingConnections())
    {
        std::cout<< "new connection" << std::endl;
        if (client == nullptr)
        {
            client = server.nextPendingConnection();
            connect(client, &QTcpSocket::readyRead, this, &MainWindow::read_data);
            ui->lb_client->setText("已连接");
            connect(client, &QTcpSocket::disconnected, this, &MainWindow::disconnected);
        }
    }
}
void MainWindow::disconnected()
{
    ui->lb_client->setText("已断开");
    client = nullptr;
}
void MainWindow::read_data()
{
    QTcpSocket *socket = qobject_cast<QTcpSocket *>(sender());
    QByteArray data = socket->readAll();
    QString str = data.data();
    ui->pte_info->append(str);
    str = "收到数据：" + str;
    // std::cout << str.toStdString() << std::endl;
    QByteArray data1 = str.toUtf8();
    socket->write(data1);


}