Qt5 移除了QHttp是因为功能重复 用QNetworkAccessManager完全能搞定
新建一个控制台应用程序
看一下QNetworkAccessManager的帮助文档
需要添加Qt + =network
新建一个类
.h文件
#ifndef DOWNPAGES_H #define DOWNPAGES_H #include<QNetworkAccessManager> #include <QObject> class DownPages : public QObject { Q_OBJECT public: explicit DownPages(QObject *parent = 0); void Do_Download(); signals: public slots: void replyFinished(QNetworkReply*); private : QNetworkAccessManager *manager; }; #endif // DOWNPAGES_H
我们声明了一个 QNetworkAccesManager
在.cpp里我们把它初始化并把它的finshed信号关联槽
并判断状态是如果 是200也就是请求正常状态把页面输出
.cpp文件
#include "downpages.h" #include <QNetworkRequest> #include<QNetworkReply> #include<QDebug> #include<QTextCodec> DownPages::DownPages(QObject *parent) : QObject(parent) { manager = new QNetworkAccessManager(this); connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*))); QUrl url; //url.setUrl("http://www.cnblogs.com/a/b"); //url.setUrl("http://www.baidu.com/"); url.setUrl("http://www.sibaieteco.com/"); //url.setUrl("www.abaibduc.com"); QNetworkRequest request(url); manager->get(request); } void DownPages::Do_Download() { } /* * 请求完成 * * */ void DownPages::replyFinished(QNetworkReply * reply) { //查看是否有错误 switch(reply->error()) { //如果没有错误把页面输出 case QNetworkReply::NoError: qDebug()<<"no error"; { QTextCodec * cod=QTextCodec::codecForName("utf-8"); QString str=cod->toUnicode(reply->readAll()); qDebug()<<str; } break; case QNetworkReply::ContentNotFoundError: { QUrl failedUrl; failedUrl = reply->request().url(); int httpStatus = reply->attribute( QNetworkRequest::HttpStatusCodeAttribute).toInt(); QString reason = reply->attribute( QNetworkRequest::HttpReasonPhraseAttribute ).toString(); qDebug()<<"url"<<failedUrl <<httpStatus<<" "<<reason; } break; default: { qDebug()<<"Have error"<<reply->errorString()<<" error "<<reply->error(); } } qDebug()<<"finished"; }
再在这个基础上添加一个下载功能
.h文件
#ifndef DOWNPAGES_H #define DOWNPAGES_H #include<QNetworkAccessManager> #include <QObject> #include <QFile> class QNetworkReply; class DownPages : public QObject { Q_OBJECT public: explicit DownPages(QObject *parent = 0); void Do_Download(); signals: public slots: void replyFinished(QNetworkReply*); void readyRead(); void downloadProgress(qint64 bytesReceived, qint64 bytesTotal); void downFinished(); private : QNetworkAccessManager *manager; QNetworkReply * managerReply; QFile *file; }; #endif // DOWNPAGES_H
.cpp文件
主要是添加 了这三个信号
managerReply = manager->get(request); connect(managerReply,SIGNAL(readyRead()),this,SLOT(readyRead())); connect(managerReply,SIGNAL(downloadProgress(qint64,qint64)), this,SLOT(downloadProgress(qint64,qint64))); connect(managerReply,SIGNAL(finished()),this,SLOT(downFinished()));
readyRead()开始下载数据
DownloadProgress显示下载的进度
还有一个finished
#include "downpages.h" #include <QNetworkRequest> #include<QNetworkReply> #include<QDebug> #include<QTextCodec> #include<QFileInfo> #include<QDir> DownPages::DownPages(QObject *parent) : QObject(parent) { manager = new QNetworkAccessManager(this); connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*))); QUrl url; //url.setUrl("http://www.cnblogs.com/a/b"); //url.setUrl("http://www.baidu.com/"); //url.setUrl("http://www.sibaieteco.com/"); url.setUrl("http://files.cnblogs.com/li-peng/WPFMultLanguageDemo.rar"); QNetworkRequest request(url); managerReply = manager->get(request); connect(managerReply,SIGNAL(readyRead()),this,SLOT(readyRead())); connect(managerReply,SIGNAL(downloadProgress(qint64,qint64)), this,SLOT(downloadProgress(qint64,qint64))); connect(managerReply,SIGNAL(finished()),this,SLOT(downFinished())); } void DownPages::Do_Download() { } void DownPages::replyFinished(QNetworkReply * reply) { switch(reply->error()) { case QNetworkReply::NoError: qDebug()<<"no error"; { QTextCodec * cod=QTextCodec::codecForName("utf-8"); QString str=cod->toUnicode(reply->readAll()); //qDebug()<<str; } break; case QNetworkReply::ContentNotFoundError: { QUrl failedUrl; failedUrl = reply->request().url(); int httpStatus = reply->attribute( QNetworkRequest::HttpStatusCodeAttribute).toInt(); QString reason = reply->attribute( QNetworkRequest::HttpReasonPhraseAttribute ).toString(); qDebug()<<"url"<<failedUrl <<httpStatus<<" "<<reason; } break; default: { qDebug()<<"Have error"<<reply->errorString()<<" error "<<reply->error(); } } qDebug()<<"finished"; } void DownPages::readyRead() { QFileInfo fileinfo(managerReply->url().path()); QString thefileName = fileinfo.fileName().isEmpty()?"index.html":fileinfo.fileName(); QString thePath ="E:/Test/Down/"; //qDebug()<<thePath; QDir createfile; bool exist = createfile.exists(thePath); if(!exist) { createfile.mkpath(thePath); } thePath +=thefileName; file=new QFile(thePath); // if(file->open(QIODevice::Append)) // { // file->write(managerReply->readAll()); // file->flush(); // file->close(); // } if(file->open(QIODevice::Append )) { file->write(managerReply->readAll()); qDebug()<<"flu"; file->flush(); } //delete file; } void DownPages::downloadProgress(qint64 bytesReceived, qint64 bytesTotal) { qDebug()<<"Total: "<<bytesTotal<<" current received : "<<bytesReceived; } void DownPages::downFinished() { file->flush(); file->close(); delete file; }
file->open(QIODevice::Append)
| 枚举值 | 描述 |
QIODevice::NotOpen |
未打开 |
QIODevice::ReadOnly |
以只读方式打开 |
QIODevice::WriteOnly |
以只写方式打开 |
QIODevice::ReadWrite |
以读写方式打开 |
QIODevice::Append |
以追加的方式打开，新增加的内容将被追加到文件末尾 |
QIODevice::Truncate |
以重写的方式打开，在写入新的数据时会将原有数据全部清除，游标设置在文件开头。 |
QIODevice::Text |
在读取时，将行结束符转换成 \n；在写入时，将行结束符转换成本地格式，例如 Win32 平台上是 \r\n |
QIODevice::Unbuffered |
忽略缓存 |
本文转自lpxxn博客园博客，原文链接：http://www.cnblogs.com/li-peng/p/3656613.html，如需转载请自行联系原作者
