最近在搞Qt的网络通信和音乐播放的应用，做完每一个部分都会上传上来。下面的这段代码中实现了访问百度主页，返回的信息可以再输出窗查看，代码中注释的部分是上传文件用的。QNetworkAccessManager是Qt4.4里才引入的类，qt4,.4之前一般都是使用QHttp实现。
类申明：
#ifndef DIALOG_H
#define DIALOG_H
#include <QtGui/QDialog>
#include <QNetworkAccessManager>
#include <QFile>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QPushButton>
#include <QHBoxLayout>
#include <QIODevice>
/********************HTTP实现通信******************************/
/*************************************************************/
/*************************************************************/
/*************************************************************/
class Dialog : public QDialog
{
Q_OBJECT
public:
Dialog(QWidget *parent = 0);
~Dialog();
protected slots:
void httpDownload();
void replyFinished(QNetworkReply*reply);
void onUploadProgress(qint64 bytesSent,qint64 butesTotal);
private:
QPushButton *download_Btn;
QFile *file;
QNetworkAccessManager *accessManager;
QNetworkRequest request;
QNetworkReply *reply;
QHBoxLayout *layout;
};
#endif // DIALOG_H
类的实现：
#include "dialog.h"
#include<QtDebug>
Dialog::Dialog(QWidget *parent)
: QDialog(parent)
{
download_Btn=new QPushButton("download");
layout=new QHBoxLayout();
layout->addWidget(download_Btn);
layout->sizeHint().height();
setLayout(layout);
connect(download_Btn,SIGNAL(clicked()),this,SLOT(httpDownload()));
}
Dialog::~Dialog()
{
}
void Dialog::httpDownload(){
//QUrl url("http://localhost:8080/uploadtest/MyUpload");
QUrl url("http://www.baidu.com");
QByteArray post_data;//上传的数据可以是QByteArray或者file类型
post_data.append("hello");
file=new QFile("/home/vino/Desktop/a.txt");
file->open(QIODevice::ReadOnly);//只读方式打开文件
accessManager=new QNetworkAccessManager(this);
request.setUrl(url);
/******************设置http的header***********************/
// request.setHeader(QNetworkRequest::ContentTypeHeader, "multipart/form-data");
// request.setHeader(QNetworkRequest::ContentTypeHeader, "application/octet-stream");//上传文件
// request.setRawHeader("Content-Disposition","form-data;name='doc';filename='a.txt'");
//request.setHeader(QNetworkRequest::ContentLengthHeader,post_data.length());
connect(accessManager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*)));//finish为manager自带的信号，replyFinished是自定义的
reply=accessManager->post(request,post_data);//通过发送数据，返回值保存在reply指针里.
//connect(reply, SIGNAL(uploadProgress ( qint64 ,qint64 )), this, SLOT( onUploadProgress(qint64 ,qint64 ));//上传文件时进度
//void QNetworkReply::downloadProgress ( qint64 bytesReceived, qint64 bytesTotal ) qt也有提供下载文件的进度
}
void Dialog::replyFinished(QNetworkReply *reply){
//获取响应的信息，状态码为200表示正常
QVariant status_code = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
//无错误返回
if(reply->error() == QNetworkReply::NoError)
{
download_Btn->setText("success");
QByteArray bytes = reply->readAll();
QString result(bytes); //转化为字符串
qDebug()<<result;
}
else
{
//处理错误
download_Btn->setText("failed");
}
reply->deleteLater();//要删除reply，但是不能在repyfinished里直接delete，要调用deletelater;
}
void Dialog::onUploadProgress(qint64 bytesSent, qint64 butesTotal){
//文件上传的进度 }
主函数：由Qtcreator自动生成
#include <QtGui/QApplication>
#include "dialog.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Dialog w;
w.show();
return a.exec();
}