【笔记】Qt5开发及实例_获取网页内容及下载功能

咚咚锵啦啦啦

头文件：MainWindwo.h

[C++] 纯文本查看 复制代码

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QUrl>
class QFile;
class QNetworkReply;
class QNetworkAccessManager;
namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT
    
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    void startRequest(QUrl url);
    
private:
    Ui::MainWindow *ui;
    QNetworkAccessManager *manager;
    QNetworkReply *reply;
    QUrl url;
    QFile *file;
private slots:
    void replyFinished(QNetworkReply *);
    void httpFinished();
    void httpReadyRead();
    void updateDataReadProgress(qint64,qint64);
    void on_pushButton_clicked();
};

#endif // MAINWINDOW_H

MainWindow.cpp

[C++] 纯文本查看 复制代码

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtNetwork>

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

    manager = new QNetworkAccessManager(this);
    connect(manager,SIGNAL(finished(QNetworkReply*)),this,SLOT(replyFinished(QNetworkReply*)));
    manager->get(QNetworkRequest(QUrl("http://www.baidu.com")));

    ui->progressBar->hide();

}

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

void MainWindow::replyFinished(QNetworkReply *reply)
{
    QString all = reply->readAll();
    ui->textBrowser->setText(all);
    reply->deleteLater();
}

void MainWindow::startRequest(QUrl url)
{
    reply = manager->get(QNetworkRequest(url));
    connect(reply,SIGNAL(readyRead()),this,SLOT(httpReadyRead()));
    connect(reply,SIGNAL(downloadProgress(qint64,qint64)),this,SLOT(updateDataReadProgress(qint64,qint64)));
    connect(reply,SIGNAL(finished()),this,SLOT(httpFinished()));
}

void MainWindow::httpReadyRead()
{
    if(file)file->write(reply->readAll());
}

void MainWindow::updateDataReadProgress(qint64 bytesRead, qint64 totalBytes)
{
    ui->progressBar->setMaximum(totalBytes);
    ui->progressBar->setValue(bytesRead);
}

void MainWindow::httpFinished()
{
    ui->progressBar->hide();
    file->flush();
    file->close();
    reply->deleteLater();
    reply = 0;
    delete file;
    file = 0;
}


void MainWindow::on_pushButton_clicked()
{
    url = ui->lineEdit->text();
    QFileInfo info(url.path());
    QString fileName(info.fileName());
    file = new QFile(fileName);
    if(!file->open(QIODevice::WriteOnly))
    {
        qDebug()<<"file open error";
        delete file;
        file = 0;
        return;
    }
    startRequest(url);
    ui->progressBar->setValue(0);
    ui->progressBar->show();
}

沙滩上de水瓶

C的好麻烦啊，易的话就是一个编辑框和一个超文本浏览框，不过C感觉比易强大