激情综合视频,亚洲日韩欧美一区二区在线,欧美二区在线观看

qthread QNetworkAccessManager QEventLoop

進(jìn)程通過(guò)QNetworkAccessManager 進(jìn)行http請(qǐng)求。代碼如下：

//qhttp.h

#ifndef QHTTP_H

#define QHTTP_H

#include <QtGui/QWidget>

#include "ui_qhttp.h"

#include <QNetworkAccessManager>

#include <QUrl>

class QPushButton;

class QDialogButtonBox;

class QNetworkReply;

class qhttp : public QWidget

{

Q_OBJECT

public:

qhttp(QWidget *parent = 0);

~qhttp();

void startRequest(QUrl url);

private:

Ui::qhttpClass ui;

QPushButton *downloadButton;

QDialogButtonBox *buttonBox;

QUrl url;

QNetworkAccessManager qnam;

QNetworkReply *reply;

private slots:

void downloadFile();

void httpFinished();

};

#endif // QHTTP_H

//qhppt.cpp

#include "qhttp.h"

#include <QtGui>

#include <QtNetwork>

#include <iostream>

using namespace std;

qhttp::qhttp(QWidget *parent)

: QWidget(parent)

{

ui.setupUi(this);

downloadButton = new QPushButton(tr("Download"));

downloadButton->setDefault(true);

buttonBox = new QDialogButtonBox;

buttonBox->addButton(downloadButton, QDialogButtonBox::ActionRole);

connect(downloadButton, SIGNAL(clicked()), this, SLOT(downloadFile()));

QVBoxLayout *mainLayout = new QVBoxLayout;

mainLayout->addWidget(buttonBox);

setLayout(mainLayout);

}

qhttp::~qhttp()

{

}

void qhttp::downloadFile()

{

cout<<"downloadFile"<<endl;

url = "http://www.baidu.com/";

startRequest(url);

}

void qhttp::startRequest(QUrl url)

{

cout<<"startRequest"<<endl;

reply = qnam.get(QNetworkRequest(url));

connect(reply, SIGNAL(finished()), this, SLOT(httpFinished()));

}

void qhttp::httpFinished()

{

cout<<"httpFinished"<<endl;

if(reply->error())

{

cout<<"error:"<<qPrintable(reply->errorString())<<endl;

}

else

{

cout<<"right"<<endl;

}

但當(dāng)主進(jìn)程開(kāi)辟線程來(lái)執(zhí)行http請(qǐng)求時(shí)，卻無(wú)法成功。

//qhttp.h

#ifndef QHTTP_H

#define QHTTP_H

#include <QtGui/QWidget>

#include "ui_qhttp.h"

#include <QNetworkAccessManager>

#include <QUrl>

class QPushButton;

class QDialogButtonBox;

class QNetworkReply;

class qhttpThread;

class qhttp : public QWidget

{

Q_OBJECT

public:

qhttp(QWidget *parent = 0);

~qhttp();

void startRequest(QUrl url);

private:

Ui::qhttpClass ui;

QPushButton *downloadButton;

QDialogButtonBox *buttonBox;

QUrl url;

QNetworkAccessManager qnam;

QNetworkReply *reply;

qhttpThread *httpthread;

private slots:

void downloadFile();

void httpFinished();

};

#endif // QHTTP_H

//qhttp.cpp

#include "qhttp.h"

#include "qhttpThread.h"

#include <QtGui>

#include <QtNetwork>

#include <iostream>

using namespace std;

qhttp::qhttp(QWidget *parent)

: QWidget(parent)

{

ui.setupUi(this);

downloadButton = new QPushButton(tr("Download"));

downloadButton->setDefault(true);

buttonBox = new QDialogButtonBox;

buttonBox->addButton(downloadButton, QDialogButtonBox::ActionRole);

connect(downloadButton, SIGNAL(clicked()), this, SLOT(downloadFile()));

QVBoxLayout *mainLayout = new QVBoxLayout;

mainLayout->addWidget(buttonBox);

setLayout(mainLayout);

}

qhttp::~qhttp()

{

}

void qhttp::downloadFile()

{

cout<<"downloadFile"<<endl;

//url = "http://www.baidu.com/";

//startRequest(url);

httpthread = new qhttpThread(this);

httpthread->start();

}

void qhttp::startRequest(QUrl url)

{

cout<<"startRequest"<<endl;

reply = qnam.get(QNetworkRequest(url));

connect(reply, SIGNAL(finished()), this, SLOT(httpFinished()));

}

void qhttp::httpFinished()

{

cout<<"httpFinished"<<endl;

if(reply->error())

{

cout<<"error:"<<qPrintable(reply->errorString())<<endl;

}

else

{

cout<<"right"<<endl;

}

此時(shí)會(huì)出現(xiàn)程序運(yùn)行崩潰、沒(méi)有執(zhí)行http請(qǐng)求任務(wù)等情況。
簡(jiǎn)單說(shuō)一下注意事項(xiàng)：
1 線程中的run函數(shù)返回后線程即結(jié)束，根本無(wú)法等到reply的finished信號(hào)。因此需要加入QEventLoop來(lái)掛起線程。

2 通過(guò)connect設(shè)置信號(hào)槽，需要QObject的支持，因此在構(gòu)造函數(shù)里與頭文件中需要修改代碼。
最終的修改代碼如下：

//qhttpThread.h

#ifndef QHTTPTHREAD_H_

#define QHTTPTHREAD_H_

#include <QThread>

#include <QObject>

#include <QNetworkAccessManager>

#include <QUrl>

class QNetworkReply;

class QEventLoop;

class qhttpThread : public QThread

{

Q_OBJECT

public:

qhttpThread(QObject *parent = 0);

virtual ~qhttpThread();

void run();

private:

QUrl url;

QNetworkAccessManager qnam;

QNetworkReply *reply;

QEventLoop *loop;

void startRequest(QUrl url);

private slots:

void httpFinished();

};

#endif /* QHTTPTHREAD_H_ */

//qhttpThread.cpp

#include "qhttpThread.h"

#include <QtNetwork>

#include <QEventLoop>

#include <iostream>

using namespace std;

qhttpThread::qhttpThread(QObject *parent) : QThread(parent)

{

// TODO Auto-generated constructor stub

}

qhttpThread::~qhttpThread()

{

// TODO Auto-generated destructor stub

}

void qhttpThread::run()

{

cout<<"run"<<endl;

url = "http://www.baidu.com/";

startRequest(url);

exec();

cout<<"run end"<<endl;

}

void qhttpThread::startRequest(QUrl url)

{

cout<<"startRequest"<<endl;

loop = new QEventLoop;

reply = qnam.get(QNetworkRequest(url));

connect(reply, SIGNAL(finished()), this, SLOT(httpFinished()));

loop->exec();

cout<<"startRequest end"<<endl;

}

void qhttpThread::httpFinished()

{

cout<<"httpFinished"<<endl;

if(reply->error())

{

cout<<"error:"<<qPrintable(reply->errorString())<<endl;

}

else

{

cout<<"right"<<endl;

}

loop->quit();

}

這樣，就可以對(duì)http進(jìn)行請(qǐng)求了。

但在真正的執(zhí)行中，當(dāng)關(guān)閉界面程序時(shí)出現(xiàn)彈出框，提示：This application has requested the Runtime to terninate it in an unusual way.
原因還在查找中。

posted on 2011-01-04 09:28 seahouse 閱讀(3701) 評(píng)論(0) 編輯收藏引用所屬分類(lèi): Qt

只有注冊(cè)用戶登錄后才能發(fā)表評(píng)論。


相關(guān)文章: Qt vlc視頻開(kāi)發(fā)libvlc_new返回空的問(wèn)題 Qt中根據(jù)拼音搜索漢字的問(wèn)題 Qt中針對(duì)Qt控件的中文翻譯 xTuple ERP: PostBooks 環(huán)境搭建 QSettings log4qt QDialog之a(chǎn)ccept QDateEdit的dataChanged信號(hào)槽執(zhí)行2次問(wèn)題 Qt 之 stylesheet 用法, QSS實(shí)例通過(guò)QPoint確定框框位置

網(wǎng)站導(dǎo)航: 博客園 IT新聞 BlogJava 博問(wèn) Chat2DB 管理

青青草原综合久久大伊人导航_色综合久久天天综合_日日噜噜夜夜狠狠久久丁香五月_热久久这里只有精品

海屋

qthread QNetworkAccessManager QEventLoop

導(dǎo)航

公告

常用鏈接

留言簿(2)

隨筆分類(lèi)

隨筆檔案

技術(shù)門(mén)戶

牛人主頁(yè)

搜索

最新評(píng)論

閱讀排行榜

評(píng)論排行榜