C++ Qt开发之使用QTcpSocket实现TCP网络通信

bool QTcpServer::listen(
    const QHostAddress &address = QHostAddress::Any, 
    quint16 port = 0
);

bool QTcpServer::waitForNewConnection(
    int msec = 0, 
    bool *timedOut = nullptr
);

QTcpSocket *QTcpServer::nextPendingConnection();

qint64 QTcpSocket::write(const char *data, qint64 maxSize);

#include <QCoreApplication>
#include <QTcpServer>
#include <QTcpSocket>
#include <iostream>

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

    QTcpServer server;

    server.listen(QHostAddress::Any,9000);
    server.waitForNewConnection(100000);

    QTcpSocket *socket;

    socket = server.nextPendingConnection();
    if(socket->state() && QAbstractSocket::ConnectedState)
    {
        QByteArray bytes = QString("lyshark").toUtf8();
        socket->write(bytes.data(),bytes.length());
    }

    socket->close();
    server.close();
    return a.exec();
}

void QTcpSocket::connectToHost(
const QString &hostName, 
quint16 port, 
OpenMode openMode = ReadWrite
);

QByteArray QTcpSocket::readAll();

#include <QCoreApplication>
#include <QTcpServer>
#include <QTcpSocket>
#include <iostream>

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

    QTcpSocket socket;
    socket.connectToHost(QHostAddress::LocalHost,9000);

    if(socket.state() && QAbstractSocket::ConnectedState)
    {
        socket.waitForReadyRead(10000);

        QByteArray ref = socket.readAll();

        QString ref_string;

        ref_string.prepend(ref);

        std::cout << ref_string.toStdString() << std::endl;
    }

    socket.close();
    return a.exec();
}

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

    // 新建TCP套接字类
    tcpServer=new QTcpServer(this);

    // 连接信号初始化其他信号
    connect(tcpServer,SIGNAL(newConnection()),this,SLOT(onNewConnection()));
}

// 初始化信号槽函数
void MainWindow::onNewConnection()
{
    // 创建新套接字
    tcpSocket = tcpServer->nextPendingConnection();

    // 连接触发信号
    connect(tcpSocket, SIGNAL(connected()),this, SLOT(onClientConnected()));
    onClientConnected();

    // 关闭触发信号
    connect(tcpSocket, SIGNAL(disconnected()),this, SLOT(onClientDisconnected()));

    // 状态改变触发信号
    connect(tcpSocket,SIGNAL(stateChanged(QAbstractSocket::SocketState)),this,SLOT(onSocketStateChange(QAbstractSocket::SocketState)));
    onSocketStateChange(tcpSocket->state());

    // 读入数据触发信号
    connect(tcpSocket,SIGNAL(readyRead()),this,SLOT(onSocketReadyRead()));
}

// 开始侦听
void MainWindow::on_pushButton_2_clicked()
{
    // 此处指定绑定本机的8888端口
    tcpServer->listen(QHostAddress::LocalHost,8888);
    ui->plainTextEdit->appendPlainText("[+] 开始监听");
    ui->plainTextEdit->appendPlainText(" 服务器地址：" + tcpServer->serverAddress().toString() +
                                       " 服务器端口："+QString::number(tcpServer->serverPort())
                                       );
}

// 停止侦听
void MainWindow::on_pushButton_3_clicked()
{
    if (tcpServer->isListening())
    {
        tcpServer->close();
    }
}

// 读取数据
void MainWindow::onSocketReadyRead()
{
    while(tcpSocket->canReadLine())
        ui->plainTextEdit->appendPlainText("[接收] | " + tcpSocket->readLine());
}

// 发送数据
void MainWindow::on_pushButton_clicked()
{
    QString  msg=ui->lineEdit->text();
    ui->plainTextEdit->appendPlainText("[发送] | " + msg);

    QByteArray str=msg.toUtf8();
    str.append('\n');
    tcpSocket->write(str);
}

// 连接服务器时触发
void MainWindow::on_pushButton_2_clicked()
{
    // 连接到8888端口
    tcpClient->connectToHost(QHostAddress::LocalHost,8888);
}

// 断开时触发
void MainWindow::on_pushButton_3_clicked()
{
    if (tcpClient->state()==QAbstractSocket::ConnectedState)
        tcpClient->disconnectFromHost();
}

// 读取数据时触发
void MainWindow::onSocketReadyRead()
{
    while(tcpClient->canReadLine())
    {
        ui->plainTextEdit->appendPlainText("[接收] | " + tcpClient->readLine());
    }
}

// 发送消息时触发
void MainWindow::on_pushButton_clicked()
{
    QString msg=ui->lineEdit->text();
    ui->plainTextEdit->appendPlainText("[发送] | " + msg);
    QByteArray str=msg.toUtf8();
    str.append('\n');
    tcpClient->write(str);
}