Qt简单下载网页

1// MainWindow.h
2class MainWindow : public QMainWindow
3{
4        Q_OBJECT
5
6public:
7        explicit MainWindow(QWidget *parent = 0);
8        ~MainWindow();
9
10public Q_SLOTS:
11        void button1Click();
12        void reply(QNetworkReply *reply);
13
14private:
15        Ui::MainWindow *ui;
16};
17
18// MainWindow.cpp
19#include <QUrl>
20#include <QNetworkReply>
21#include <QNetworkRequest>
22#include <QNetworkAccessManager>
23
24MainWindow::MainWindow(QWidget *parent) :
25    QMainWindow(parent),
26    ui(new Ui::MainWindow)
27{
28    ui->setupUi(this);
29    QObject::connect(ui->pushButton_1, SIGNAL(clicked()), this, SLOT(button1Click()));
30}
31
32MainWindow::~MainWindow()
33{
34    delete ui;
35}
36
37void MainWindow::reply(QNetworkReply *reply)
38{
39    qDebug() << reply->readAll().size(); // 获取的网页数据大小，0表示下载失败
40    reply->deleteLater();
41}
42
43void MainWindow::button1Click()
44{
45    QNetworkAccessManager *nm = new QNetworkAccessManager(this);
46    // 必须用信号和槽连接
47    connect(nm, SIGNAL(finished(QNetworkReply*)), this, SLOT(reply(QNetworkReply*)));
48    // 需要下载的网页url地址，有些网址用这种简单方法无法获取数据
49    QNetworkRequest request(QUrl("http://www.baidu.com"));
50    nm->get(request);
51}