#include?“downloadcontrol.h“
#include?

DownloadControl::DownloadControl（Qobject?*parent）?:
????Qobject（parent）
{
????state?=?Waiting;
????file?=?NULL;
}

QString?DownloadControl::errorString（）
{
????return?errorInfo;
}

qint64?DownloadControl::getFileSize（QString?url?int?tryTimes）
{
????qint64?size?=?-1;

????//嘗試tryTimes次
????while（tryTimes?--）
????{
????????QNetworkAccessManager?manager;
????????QEventLoop?loop;

????????//發出請求，獲取目標地址的頭部信息
????????QNetworkReply?*reply?=?manager.head（QNetworkRequest（url））;
????????if（!reply）continue;

????????connect（reply?SIGNAL（finished（））?&loop?SLOT（quit（）））;
????????loop.exec（）;

????????if（reply->error（）?!=?QNetworkReply::NoError）
????????{
????????????errorInfo?=?reply->errorString（）;
????????????co

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2014-06-25?08:36??ThreadDownload\
?????文件?????????700??2014-06-25?08:35??ThreadDownload\config.h
?????文件???????67646??2014-06-25?08:02??ThreadDownload\download.ico
?????文件????????8322??2014-06-25?08:18??ThreadDownload\downloadcontrol.cpp
?????文件????????2071??2014-06-25?08:18??ThreadDownload\downloadcontrol.h
?????文件????????2689??2014-06-25?08:18??ThreadDownload\downloadthread.cpp
?????文件????????1310??2014-06-25?08:18??ThreadDownload\downloadthread.h
?????文件????????2523??2014-06-25?08:18??ThreadDownload\downloadwidgets.cpp
?????文件?????????619??2014-06-25?08:18??ThreadDownload\downloadwidgets.h
?????文件?????????975??2014-06-25?07:58??ThreadDownload\main.cpp
?????文件?????????766??2014-06-24?16:11??ThreadDownload\mainwindow.ui
?????文件?????????572??2014-06-25?08:02??ThreadDownload\ThreadDownload.pro
?????文件????????6082??2014-06-25?08:23??ThreadDownload\widget.cpp
?????文件????????1145??2014-06-25?08:23??ThreadDownload\widget.h