19d8cade29
提供网络协议的7层模型中的 中高层的网络协议：Http/FTP/SNMP等 QNetworkAccessmanager 协调网络操作类（处理网络的请求和回应）：负责发送网络请求，创建网络响应 QNetworkRequest 网络请求 QNetworkReply 网络请求的响应（提供finished()/readyRead()/downloadProgress()信号），监测网络响应的执行情况，执行相应的操作
110 lines
3.0 KiB
Plaintext
110 lines
3.0 KiB
Plaintext
#include "ExHttp.h"
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#include "ui_ExHttp.h"
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#include <QMessageBox>
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#include <QDir>
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#include <QDesktopServices>
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ExHttp::ExHttp(QWidget *parent) :
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QMainWindow(parent),
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ui(new Ui::ExHttp)
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{
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ui->setupUi(this);
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setWindowTitle("QNetworkAccessManager 网络管理使用 Http 协议下载");
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m_networkManager = new QNetworkAccessManager(this);
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m_reply = nullptr;
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m_file = nullptr;
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}
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ExHttp::~ExHttp()
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{
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delete ui;
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}
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//下载文件
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void ExHttp::on_btnDown_clicked()
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{
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QString urlSpec = ui->lineEditUrl->text().trimmed(); //去掉字符串的首尾的空格
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if (urlSpec.isEmpty()) {
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QMessageBox::information(this, "提示", "下载地址URL为NULL");
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return;
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}
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QUrl url = QUrl::fromUserInput(urlSpec);
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if (!url.isValid()) {
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QMessageBox::information(this, "提示", QString("无效URL: %1 \n 错误信息: %2").arg(urlSpec, url.errorString()));
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return;
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}
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QString dir = ui->lineEditFile->text().trimmed();
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if (dir.isEmpty()) {
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QMessageBox::information(this, "提示", "保存地址为空");
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return;
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}
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QString fileFileName = dir + url.fileName(); //文件保存地址 + 文件名
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if (QFile::exists(fileFileName))
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QFile::remove(fileFileName);
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m_file = new QFile(fileFileName); //创建临时文件
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if (!m_file->open(QIODevice::WriteOnly)) {
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QMessageBox::information(this, "提示", "打开临时文件错误");
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return;
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}
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ui->btnDown->setEnabled(false);
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m_reply = m_networkManager->get(QNetworkRequest(url)); //发送get网络请求，创建网络响应
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connect(m_reply, SIGNAL(finished()), this, SLOT(onFinished()));
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connect(m_reply, SIGNAL(readyRead()), this, SLOT(onReadyRead()));
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connect(m_reply, SIGNAL(downloadProgress(qint64,qint64)), this, SLOT(onDownloadProgress(qint64,qint64)));
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}
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//默认的保存路径
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void ExHttp::on_btnFile_clicked()
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{
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QString currPath = QDir::currentPath();
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QDir dir(currPath);
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dir.mkdir("temp");
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ui->lineEditFile->setText(currPath + "/temp/");
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}
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//网络响应结束
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void ExHttp::onFinished()
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{
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QFileInfo fileInfo;
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fileInfo.setFile(m_file->fileName());
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m_file->close();
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delete m_file;
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m_file = nullptr;
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m_reply->deleteLater();
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m_reply = nullptr;
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if (ui->checkBox->isChecked()) //勾选了，下载完成之后，打开下载的文件 //absoluteFilePath() 返回包含文件名的绝对路径。
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QDesktopServices::openUrl(QUrl::fromLocalFile(fileInfo.absoluteFilePath())); //使用默认软件的打开下载的文件
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ui->btnDown->setEnabled(true);
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}
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//读取下载的数据
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void ExHttp::onReadyRead()
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{
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m_file->write(m_reply->readAll()); //将返回的数据进行读取，写入到临时文件中
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}
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//下载进程
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void ExHttp::onDownloadProgress(qint64 bytesRea, qint64 totalBytes)
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{
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ui->progressBar->setMaximum(totalBytes);
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ui->progressBar->setValue(bytesRea);
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}
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void ExHttp::on_lineEditUrl_textChanged(const QString &arg1)
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{
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ui->progressBar->setMaximum(100);
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ui->progressBar->setValue(0);
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}
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