#include "httpclient.h"HttpClient::HttpClient( QWidget *parent, Qt::WindowFlags  f )    : QDialog( parent, f ){      QFont font("ZYSong18030",12);    setFont(font);	        setWindowTitle(tr("Http Client"));        urlLabel = new QLabel( this );    urlLabel->setText(tr("Url:"));        urlLineEdit = new QLineEdit( this );        progressBar = new QProgressBar( this );        downloadPushButton = new QPushButton( this);    downloadPushButton->setText( tr( "Download" ) );          cancelPushButton = new QPushButton( this);    cancelPushButton->setText( tr( "Cancel" ) );              exitPushButton = new QPushButton( this);    exitPushButton->setText( tr( "Exit" ) );              QHBoxLayout *hbLayout1 = new QHBoxLayout();    hbLayout1->addWidget( urlLabel );    hbLayout1->addWidget( urlLineEdit );    QHBoxLayout *hbLayout2 = new QHBoxLayout();    hbLayout2->addWidget( progressBar );        QHBoxLayout *hbLayout3 = new QHBoxLayout();    hbLayout3->addWidget( downloadPushButton );    hbLayout3->addWidget( cancelPushButton );     hbLayout3->addWidget( exitPushButton );            QVBoxLayout *vbLayout = new QVBoxLayout( this );    vbLayout->addLayout( hbLayout1 );    vbLayout->addLayout( hbLayout2 );    vbLayout->addLayout( hbLayout3 );    httpClient = new QHttp(this);    connect(httpClient, SIGNAL(requestFinished(int, bool)),this, SLOT(httpRequestFinished(int, bool)));    connect(httpClient, SIGNAL(dataReadProgress(int, int)),this, SLOT(httpDataReadProgress(int, int)));    connect(httpClient, SIGNAL(responseHeaderReceived(const QHttpResponseHeader &)),this, SLOT(httpResponseHeaderReceived(const QHttpResponseHeader &)));	connect(downloadPushButton,SIGNAL(clicked()),this,SLOT(slotDownload()));    connect(cancelPushButton,SIGNAL(clicked()),this,SLOT(slotCancel()));    connect(exitPushButton,SIGNAL(clicked()),this,SLOT(slotExit()));    	cancelPushButton->setEnabled(false);}HttpClient::~HttpClient(){}                                                                             void HttpClient::slotDownload(){	QUrl url(urlLineEdit->text());    QFileInfo fileInfo(url.path());    QString fileName = fileInfo.fileName();    if (QFile::exists(fileName))     {        QMessageBox::information(this, tr("Error"),tr("File already exists!"));        return;    }    file = new QFile(fileName);    if (!file->open(QIODevice::WriteOnly))     {        QMessageBox::information(this, tr("Error"),tr("Save file error!"));        delete file;        file = 0;        return;    }        httpClient->setHost(url.host(), url.port() != -1 ? url.port() : 80);    if (!url.userName().isEmpty())    {        httpClient->setUser(url.userName(), url.password());    }    httpRequestAborted = false;    requestId = httpClient->get(url.path(), file);    progressBar->reset();    downloadPushButton->setEnabled(false);    cancelPushButton->setEnabled(true);}void HttpClient::slotCancel(){    httpRequestAborted = true;    httpClient->abort();    downloadPushButton->setEnabled(true);    cancelPushButton->setEnabled(false);	}	void HttpClient::slotExit(){	accept();}void HttpClient::httpRequestFinished(int id, bool error){    if (httpRequestAborted)     {        if (file)         {            file->close();            file->remove();            delete file;            file = 0;        }        progressBar->reset();        return;    }    if (id == requestId)    {		progressBar->reset();		file->close();				if (error) 		{		    file->remove();		    QMessageBox::information(this, tr("Error"),tr("Download failed!"));		} 		downloadPushButton->setEnabled(true);		cancelPushButton->setEnabled(false);		delete file;		file = 0;	}}void HttpClient::httpDataReadProgress(int done, int total){	progressBar->setMaximum(total);    progressBar->setValue(done);}void HttpClient::httpResponseHeaderReceived(const QHttpResponseHeader &responseHeader){	if (responseHeader.statusCode() != 200) 	{		QMessageBox::information(this, tr("Error"),	tr("Download error!"));		httpRequestAborted = true;		progressBar->reset();		httpClient->abort();		return;	}}