在项目中需要用到程序更新的功能,同事介绍说是curl中的开发库很不错,于是下载这个包测试了一下,确实不错。准备正式用到项目中,以下一个例子用于从互联网上抓取一个文件下载到本地,并加上进度条显示,做得挺简陋,不过功能差不多就这样了。
程序运行预览.
首先需要加入多线程的机制,因为程序一边在下载文件,一边在显示进度条,单线程的方式肯定不行,所以我用到了wxTimer来实现,在downloadMain.h 中定义了一个wxTimer,并做了事件申明.
DECLARE_EVENT_TABLE()
DECLARE_EVENT_TABLE()
/***************************************************************
* Name: downloadMain.h
* Purpose: Defines Application Frame
* Author: ()
* Created: 2008-11-14
* Copyright: ()
* License:
**************************************************************/
#ifndef DOWNLOADMAIN_H
#define DOWNLOADMAIN_H
#include "downloadApp.h"
#include <wx/timer.h>
#include "GUIDialog.h"
class downloadDialog: public GUIDialog
{
public:
downloadDialog(wxDialog *dlg);
~downloadDialog();
void .Timer(wxTimerEvent& event);
private:
virtual void .Close(wxCloseEvent& event);
virtual void .Quit(wxCommandEvent& event);
virtual void .About(wxCommandEvent& event);
void downloadfile();
wxTimer* m_timerdown;
DECLARE_EVENT_TABLE()
};
#endif // DOWNLOADMAIN_H
* Name: downloadMain.h
* Purpose: Defines Application Frame
* Author: ()
* Created: 2008-11-14
* Copyright: ()
* License:
**************************************************************/
#ifndef DOWNLOADMAIN_H
#define DOWNLOADMAIN_H
#include "downloadApp.h"
#include <wx/timer.h>
#include "GUIDialog.h"
class downloadDialog: public GUIDialog
{
public:
downloadDialog(wxDialog *dlg);
~downloadDialog();
void .Timer(wxTimerEvent& event);
private:
virtual void .Close(wxCloseEvent& event);
virtual void .Quit(wxCommandEvent& event);
virtual void .About(wxCommandEvent& event);
void downloadfile();
wxTimer* m_timerdown;
DECLARE_EVENT_TABLE()
};
#endif // DOWNLOADMAIN_H
下面是主程序的代码.
/***************************************************************
* Name: downloadMain.cpp
* Purpose: Code for Application Frame
* Author: (alan)
* Created: 2008-11-14
* License:
**************************************************************/
#ifdef WX_PRECOMP
#include "wx_pch.h"
#endif
#ifdef __BORLANDC__
#pragma hdrstop
#endif //__BORLANDC__
#include "downloadMain.h"
#include <curl/curl.h>
#include <curl/types.h>
#include <curl/easy.h>
#include "update.h"
#include <wx/msgdlg.h>
#include <wx/utils.h>
#define TIMER_ID 22222
//事件监听声明
BEGIN_EVENT_TABLE(downloadDialog, GUIDialog)
EVT_TIMER(TIMER_ID, downloadDialog::OnTimer)
END_EVENT_TABLE()
enum wxbuildinfoformat
{
short_f, long_f
};
wxString wxbuildinfo(wxbuildinfoformat format)
{
wxString wxbuild(wxVERSION_STRING);
if (format == long_f )
{
#if defined(__WXMSW__)
wxbuild << _T("-Windows");
#elif defined(__WXMAC__)
wxbuild << _T("-Mac");
#elif defined(__UNIX__)
wxbuild << _T("-Linux");
#endif
#if wxUSE_UNICODE
wxbuild << _T("-Unicode build");
#else
wxbuild << _T("-ANSI build");
#endif // wxUSE_UNICODE
}
return wxbuild;
}
//声明一个文件结构体
struct FtpFile
{
char *filename;
FILE *stream;
};
downloadDialog::downloadDialog(wxDialog *dlg)
: GUIDialog(dlg)
{
//创建一个定时器,制定TIMER_ID
m_timerdown = new wxTimer(this, TIMER_ID);
//定时器开始运行,这里会自动执行OnTimer函数
m_timerdown->Start(100);
}
downloadDialog::~downloadDialog()
{
}
//定时器操作
void downloadDialog::OnTimer(wxTimerEvent &event)
{
downloadfile();
}
//文件写入流
int my_fwrite(void *buffer, size_t size, size_t nmemb, void *stream)
{
struct FtpFile *out=(struct FtpFile *)stream;
if (out && !out->stream)
{
out->stream=fopen(out->filename, "wb");
if (!out->stream)
{
return -1;
}
}
return fwrite(buffer, size, nmemb, out->stream);
}
//进度条显示函数
int wxcurldav_dl_progress_func(void* ptr, double rDlTotal, double rDlNow, double rUlTotal, double rUlNow)
{
wxGauge* pGauge = (wxGauge*) ptr;
if(pGauge)
//设置进度条的值
pGauge->SetValue(100.0 * (rDlNow/rDlTotal));
return 0;
}
//下载文件函数
void downloadDialog::downloadfile()
{
//创建curl对象
CURL *curl;
CURLcode res;
m_staticText2->SetLabel(wxT("请耐心等待程序下载更新包..."));
struct FtpFile ftpfile=
{
//定义下载到本地的文件位置和路径
"tmp.exe",NULL
};
curl_global_init(CURL_GLOBAL_DEFAULT);
//curl初始化
curl = curl_easy_init();
//curl对象存在的情况下执行操作
if (curl)
{
//设置远端地址
curl_easy_setopt(curl, CURLOPT_URL,"http://dl_dir.qq.com/minigamefile/QQGame2008ReleaseP2_web_setup.EXE");
//执行写入文件流操作
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_fwrite);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ftpfile);
//curl的进度条声明
curl_easy_setopt(curl, CURLOPT_NOPROGRESS, FALSE);
//回调进度条函数
curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, wxcurldav_dl_progress_func);
//设置进度条名称
curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, m_gauge1);
//进度条
m_gauge1->SetValue(0);
//写入文件
res = curl_easy_perform(curl);
m_gauge1->SetValue(100);
//释放curl对象
curl_easy_cleanup(curl);
if (CURLE_OK != res)
;
}
if (ftpfile.stream)
{
//关闭文件流
fclose(ftpfile.stream);
}
//释放全局curl对象
curl_global_cleanup();
//这一步很重要,停止定时器,不然程序会无休止的运行下去
m_timerdown->Stop();
//执行刚下载完毕的程序,进行程序更新
int pid = ::wxExecute(_T("tmp.exe"));
wxMessageBox(wxT("下载完毕,程序开始执行更新操作......"));
}
void downloadDialog::OnClose(wxCloseEvent &event)
{
Destroy();
}
void downloadDialog::OnQuit(wxCommandEvent &event)
{
Destroy();
}
void downloadDialog::OnAbout(wxCommandEvent &event)
{
}
* Name: downloadMain.cpp
* Purpose: Code for Application Frame
* Author: (alan)
* Created: 2008-11-14
* License:
**************************************************************/
#ifdef WX_PRECOMP
#include "wx_pch.h"
#endif
#ifdef __BORLANDC__
#pragma hdrstop
#endif //__BORLANDC__
#include "downloadMain.h"
#include <curl/curl.h>
#include <curl/types.h>
#include <curl/easy.h>
#include "update.h"
#include <wx/msgdlg.h>
#include <wx/utils.h>
#define TIMER_ID 22222
//事件监听声明
BEGIN_EVENT_TABLE(downloadDialog, GUIDialog)
EVT_TIMER(TIMER_ID, downloadDialog::OnTimer)
END_EVENT_TABLE()
enum wxbuildinfoformat
{
short_f, long_f
};
wxString wxbuildinfo(wxbuildinfoformat format)
{
wxString wxbuild(wxVERSION_STRING);
if (format == long_f )
{
#if defined(__WXMSW__)
wxbuild << _T("-Windows");
#elif defined(__WXMAC__)
wxbuild << _T("-Mac");
#elif defined(__UNIX__)
wxbuild << _T("-Linux");
#endif
#if wxUSE_UNICODE
wxbuild << _T("-Unicode build");
#else
wxbuild << _T("-ANSI build");
#endif // wxUSE_UNICODE
}
return wxbuild;
}
//声明一个文件结构体
struct FtpFile
{
char *filename;
FILE *stream;
};
downloadDialog::downloadDialog(wxDialog *dlg)
: GUIDialog(dlg)
{
//创建一个定时器,制定TIMER_ID
m_timerdown = new wxTimer(this, TIMER_ID);
//定时器开始运行,这里会自动执行OnTimer函数
m_timerdown->Start(100);
}
downloadDialog::~downloadDialog()
{
}
//定时器操作
void downloadDialog::OnTimer(wxTimerEvent &event)
{
downloadfile();
}
//文件写入流
int my_fwrite(void *buffer, size_t size, size_t nmemb, void *stream)
{
struct FtpFile *out=(struct FtpFile *)stream;
if (out && !out->stream)
{
out->stream=fopen(out->filename, "wb");
if (!out->stream)
{
return -1;
}
}
return fwrite(buffer, size, nmemb, out->stream);
}
//进度条显示函数
int wxcurldav_dl_progress_func(void* ptr, double rDlTotal, double rDlNow, double rUlTotal, double rUlNow)
{
wxGauge* pGauge = (wxGauge*) ptr;
if(pGauge)
//设置进度条的值
pGauge->SetValue(100.0 * (rDlNow/rDlTotal));
return 0;
}
//下载文件函数
void downloadDialog::downloadfile()
{
//创建curl对象
CURL *curl;
CURLcode res;
m_staticText2->SetLabel(wxT("请耐心等待程序下载更新包..."));
struct FtpFile ftpfile=
{
//定义下载到本地的文件位置和路径
"tmp.exe",NULL
};
curl_global_init(CURL_GLOBAL_DEFAULT);
//curl初始化
curl = curl_easy_init();
//curl对象存在的情况下执行操作
if (curl)
{
//设置远端地址
curl_easy_setopt(curl, CURLOPT_URL,"http://dl_dir.qq.com/minigamefile/QQGame2008ReleaseP2_web_setup.EXE");
//执行写入文件流操作
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_fwrite);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ftpfile);
//curl的进度条声明
curl_easy_setopt(curl, CURLOPT_NOPROGRESS, FALSE);
//回调进度条函数
curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, wxcurldav_dl_progress_func);
//设置进度条名称
curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, m_gauge1);
//进度条
m_gauge1->SetValue(0);
//写入文件
res = curl_easy_perform(curl);
m_gauge1->SetValue(100);
//释放curl对象
curl_easy_cleanup(curl);
if (CURLE_OK != res)
;
}
if (ftpfile.stream)
{
//关闭文件流
fclose(ftpfile.stream);
}
//释放全局curl对象
curl_global_cleanup();
//这一步很重要,停止定时器,不然程序会无休止的运行下去
m_timerdown->Stop();
//执行刚下载完毕的程序,进行程序更新
int pid = ::wxExecute(_T("tmp.exe"));
wxMessageBox(wxT("下载完毕,程序开始执行更新操作......"));
}
void downloadDialog::OnClose(wxCloseEvent &event)
{
Destroy();
}
void downloadDialog::OnQuit(wxCommandEvent &event)
{
Destroy();
}
void downloadDialog::OnAbout(wxCommandEvent &event)
{
}
本文转自阿汐 51CTO博客,原文链接:http://blog.51cto.com/axiii/112836,如需转载请自行联系原作者