QT–HTTP文件下载器
1.pro文件添加
QT += core gui network
2.头文件
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QFile>
3.widget.h文件
#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
4.widget.cpp文件
#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()-1);
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(0); //设置进度条初始化为0
ui->progressBar->setMinimum(0);
}
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()-1);
QString data = "下载成功--" + filename;
ui->textEdit->setText(data);
}
void Widget::doProcessError(QNetworkReply::NetworkError code)
{
qDebug() << code;
}
Widget::~Widget()
{
delete ui;
}
5.widget.ui文件
6.工程源码
github