#include <QNetworkAccessManager>

#include <QNetworkReply>

#include <QNetworkRequest>

#include <QFile>

#ifndef WIDGET_H

#define WIDGET_H

​

#include <QWidget>

#include <QNetworkAccessManager>

#include <QNetworkReply>

#include <QNetworkRequest>

#include <QFile>

​

namespace Ui {

class Widget;

}

​

class Widget : public QWidget

{

    Q_OBJECT

​

public:

    explicit Widget(QWidget *parent = nullptr);

    ~Widget();

​

    QNetworkAccessManager *manager;

    QNetworkReply *reply;

    QFile *myfile;

​

    void Init();

​

    void doProcessReadyRead();

    void doProcessFinished();

    void doProcessDownloadProgress(qint64,qint64);

    void doProcessError(QNetworkReply::NetworkError code);

private slots:

    void on_pushButton_clicked();

​

private:

    Ui::Widget *ui;

};

​

#endif // WIDGET_H

​

#include "widget.h"

#include "ui_widget.h"

#include <QDebug>

#include <QFile>

#include <QMessageBox>

#include <QDebug>

​

Widget::Widget(QWidget *parent) :

    QWidget(parent),

    ui(new Ui::Widget)

{

    ui->setupUi(this);

    Init();

​

}

​

void Widget::Init()

{

​

    manager = new QNetworkAccessManager(this);

    myfile = new QFile(this);

}

​

​

void Widget::on_pushButton_clicked()

{

    QNetworkRequest request;

    QString url = ui->lineEdit->text();

    request.setUrl(QUrl(url));

​

    reply = manager->get(request);              //发送请求

​

    connect(reply,&QNetworkReply::readyRead,this,&Widget::doProcessReadyRead);                //可读

    connect(reply,&QNetworkReply::finished,this,&Widget::doProcessFinished);                  //结束

    connect(reply,&QNetworkReply::downloadProgress,this,&Widget::doProcessDownloadProgress);  //大小

    connect(reply,QOverload<QNetworkReply::NetworkError>::of(&QNetworkReply::error),          //异常

            this,&Widget::doProcessError);

​

    QStringList list = url.split("/");

    QString filename = list.at(list.length()-);

    QString file = "E:/tp/" + filename;

    myfile->setFileName(file);

   bool ret = myfile->open(QIODevice::WriteOnly|QIODevice::Truncate);    //创建文件

    if(!ret)

    {

        QMessageBox::warning(this,"warning","打开失败");

        return;

    }

​

    ui->progressBar->setValue();             //设置进度条初始化为0

    ui->progressBar->setMinimum();

}

​

void Widget::doProcessReadyRead()             //读取并写入

{

    while(!reply->atEnd())

    {

        QByteArray ba = reply->readAll();

        myfile->write(ba);

    }

}

​

void Widget::doProcessFinished()

{

    myfile->close();

}

​

void Widget::doProcessDownloadProgress(qint64 recv_total, qint64 all_total)      //显示

{

    ui->progressBar->setMaximum(all_total);

    ui->progressBar->setValue(recv_total);

​

    QStringList list = ui->lineEdit->text().split("/");

    QString filename = list.at(list.length()-);

    QString data = "下载成功--" + filename;

    ui->textEdit->setText(data);

}

​

void Widget::doProcessError(QNetworkReply::NetworkError code)

{

    qDebug() << code;

}

​

Widget::~Widget()

{

    delete ui;

}

​

​