请问如何做一个tcp客户端访问网页
本帖最后由 oXiFangShiBai 于 2013-02-01 10:28:15 编辑 使用tcp协议，来访问网页，这样主要是做一个长连接

我的实现思路是：
1.连接 服务器 【举例用百度 www.baidu.com】
2.发送http协议头，获取服务器返回网页内容 并 处于监控状态，因为服务器会每隔1分钟发心跳包给我，我的目的就是要得到心跳包的内容，
3.我的代码如下，出现的问题是，发送了http协议头，服务器没有任何反映，我用wireshark抓包，甚至没有变成http请求，我想，一定是我发送的时候出了问题，但自己研究了半天没弄好，所以来请教大家

下面贴上我的代码


client.h

//client.h
#ifndef TRYCLI_H_
#define TRYCLI_H_

#include <QtNetwork>
#include <QtGui>
#include <QtCore>
#include <QWidget>
#include <QLineEdit>


#include <QLabel>
#include <QPushButton>
class Client : public QWidget
{
    Q_OBJECT
private:
    bool isConnected;
    QLineEdit *serverIpEdit;
    QLabel *label;
    QPushButton *startButton;
    QTcpSocket *tcpClient;
    quint16 blockSize;
    QString sendString;
    QString readString;

public:
    Client();
    ~Client();

    public slots:
        void displayError(QAbstractSocket::SocketError socketError);
        void newConnect();
        void readMessage();
        void sendMessage();

};

#endif

//client.cpp

//client.cpp
#include "client.h"
#include <QMessageBox>
#include <QHBoxLayout>
#include <QtEvents>
#include <QTextEdit>
#include <QDebug>
#include <QString>
Client::Client()
{
    setWindowTitle("Client");
    resize(300, 100);

    serverIpEdit = new QLineEdit("www.baidu.com");
    startButton = new QPushButton("start");
    label = new QLabel("Emtpy");
    isConnected = false;

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(serverIpEdit);
    layout->addWidget(label);

    layout->addWidget(startButton);
    setLayout(layout);

    tcpClient = new QTcpSocket(this);
    connect(startButton, SIGNAL(clicked()), this, SLOT(newConnect()));
    connect(tcpClient, SIGNAL(connected()), this, SLOT(sendMessage()));
    connect(tcpClient, SIGNAL(readyRead()), this, SLOT(readMessage()));
    connect(tcpClient, SIGNAL(error(QAbstractSocket::SocketError)),
        this, SLOT(displayError(QAbstractSocket::SocketError)));
}

Client::~Client()
{

}

void Client::newConnect()
{
    blockSize = 0;
    tcpClient->abort();
    tcpClient->connectToHost(serverIpEdit->text(), 80); 
 

}

void Client::sendMessage()
{
    qDebug()<<"runing:sendMessage";

    char*  ch="GET /  HTTP/1.1 \n            Connection: Keep-Alive";
    QByteArray ba = sendString.toLatin1();
    ch=ba.data();
    tcpClient->write(ch,39);
    qDebug()<<ch;
}

void Client::readMessage()
{
    qDebug()<<"runing:readMessage";
    QDataStream in(tcpClient);
    in.setVersion(QDataStream::Qt_4_0);

    if (blockSize == 0)
    {
        if (tcpClient->bytesAvailable() < (int)sizeof(quint16))
            return;
        in >> blockSize;
    }
    if (tcpClient->bytesAvailable() < blockSize)
        return;

    in >> readString;
    label->setText(readString);



    qDebug()<<tcpClient->readAll();
}

void Client::displayError(QAbstractSocket::SocketError socketError)
{
    switch (socketError) {
    case QAbstractSocket::RemoteHostClosedError:
        break;
    case QAbstractSocket::HostNotFoundError:
        QMessageBox::information(this, tr("Fortune Client"),
            tr("The host was not found. Please check the "
            "host name and port settings."));
        break;
    case QAbstractSocket::ConnectionRefusedError:
        QMessageBox::information(this, tr("Fortune Client"),
            tr("The connection was refused by the peer. "
            "Make sure the fortune server is running, "
            "and check that the host name and port "
            "settings are correct."));
        break;
    default:
        QMessageBox::information(this, tr("Fortune Client"),
            tr("The following error occurred: %1.")
            .arg(tcpClient->errorString()));
    }
}

//main.cpp

//main.cpp
#include "client.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv); 
 
    Client w;
    w.show();
    return a.exec();
}

请大家指点 c++ tcp
[解决办法]
http头请求，一句代码就要跟一个"\r\n"，你可以试一下
GET / HTTP/1.1 \r\n Connection: Keep-Alive\r\n\r\n

我之前用C写过，可以参考：http://blog.csdn.net/gzshun/article/details/7213876