【Y忍冬草】Qt之客户端实现数据的接收和发送_qt客户端发送数据到nodered

在使用通信功能时，需要在.pro工程中添加QT += network
相关代码：

tcpClient.h文件：

#ifndef TCPCLIENT_H
#define TCPCLIENT_H

#include <QWidget>
#include <QtNetwork>


namespace Ui {
class TcpClient;
}

class TcpClient : public QWidget
{
    Q_OBJECT

public:
    explicit TcpClient(QWidget *parent = 0);
    ~TcpClient();

private slots:
    void NewConnect();  // 连接服务器
    void ReadMessage(); // 接收数据
    void SendMessage(); // 发送数据
    void DisplayError(QAbstractSocket::SocketError); // 显示错误

    void on_connectBtn_clicked();

private:
    Ui::TcpClient *ui;

    QTcpSocket *c_tcpSocket;
    QString     c_readMsg;   // 存放从服务器接收到的字符串
    QString     c_sendMsg;   // 存放发送给服务器的字符串
};

#endif // TCPCLIENT_H
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tcpClient.cpp文件：

#include "tcpclient.h"
#include "ui_tcpclient.h"
#include <QMessageBox>


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

    c_tcpSocket = new QTcpSocket(this);

    // 信号和槽的连接
    connect(c_tcpSocket, SIGNAL(readyRead()), this, SLOT(ReadMessage()));
    connect(c_tcpSocket, SIGNAL(error(QAbstractSocket::SocketError)),
            this, SLOT(DisplayError(QAbstractSocket::SocketError)));
//    connect(c_tcpSocket, SIGNAL(connected()), this, SLOT(SendMessage()));
    connect(ui->sendBtn, SIGNAL(clicked()), this, SLOT(SendMessage()));
}

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

void TcpClient::NewConnect()
{
    c_tcpSocket->abort(); // 取消已有的连接
    c_tcpSocket->connectToHost("192.168.1.111", 60000); // 连接到服务器
    if (c_tcpSocket->waitForConnected(5000))
    {
//        QString str = QString::fromLocal8Bit("通信成功!\n");
        ui->readMsg->setText(tr("通信成功!\n"));
    }
    else
    {
//        QString::fromLocal8Bit("通信失败!")
        QMessageBox::critical(this, "Client", tr("通信失败!"));
    }
}

void TcpClient::ReadMessage()
{
    // 读取数据
    while (c_tcpSocket->bytesAvailable() > 0)
    {
        QByteArray inBlock;
        // 设置数据大小为读取的数据大小
        inBlock.resize(c_tcpSocket->bytesAvailable());
        c_tcpSocket->read(inBlock.data(), inBlock.size());

        c_readMsg = QString(inBlock);

        // 显示接收到的数据
        ui->readMsg->setText(c_readMsg);
    }
}

void TcpClient::SendMessage()
{
    c_sendMsg = ui->sendMsg->text();

    // 发送数据
    c_tcpSocket->write(c_sendMsg.toLatin1(), c_sendMsg.length());
    c_tcpSocket->waitForBytesWritten();

    ui->sendMsg->clear();
}

void TcpClient::DisplayError(QAbstractSocket::SocketError)
{
    // 输出错误信息
    QString str = c_tcpSocket->errorString();
    ui->errorMsg->setText(str);

    c_tcpSocket->close();
}

// 连接按钮
void TcpClient::on_connectBtn_clicked()
{
    NewConnect(); // 请求连接
}
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相关下载：
http://download.csdn.net/download/y363703390/10202019