遍历所有时区的代码[windows]

windows没有提供遍历时区的代码，只提供了一些接口，让用户自己从注册表中遍历。比较麻烦，下面代码把这个功能封装了一下，让用户可以比较简单地处理所有时区。

其中字符串用的是core::cstringex，大家可以用STD里面的字符串来代替，core::datetime里的数据结构体和SYSTEMTIME一样，大家可以把SYSTEMTIME封装一下就可以替换它了。

//timezone.h

#ifndef timezone_h__
#define timezone_h__
/********************************************************************
purpose: support for time zone properties.
*********************************************************************/
#include "core\container\cvector.h"
#include <winbase.h>
#include "core\string\cstringex.h"
#include "core\time\datetime.h"


namespace Timezone
{
typedef struct _tagTimezoneInfo
{
core::cstringexm_displayName;
TIME_ZONE_INFORMATIONm_tzi;
} TimezoneInfo,*LPTimezoneInfo;


core::cvector<TimezoneInfo> const&getTimeZoneList();
TimezoneInfo const*lookupTimeZone(core::cstringex const& tziUniqueString);


TimezoneInfo const&getTimeZone(unsigned int idx);
bool setTimeZone(TIME_ZONE_INFORMATION const& tzi, bool bDaylightSaving);  //invoker pays attention to WIN_CE 


core::datetime getLocalDatetime( core::datetime utc0DT,TIME_ZONE_INFORMATION const& tzi );
core::datetime getUTC0Datetime( core::datetime localDT,TIME_ZONE_INFORMATION const& tzi );


bool isDaylightSavingAvailable(TIME_ZONE_INFORMATION const& tzi);
bool isInDaylightSavingPeriod(TIME_ZONE_INFORMATION const& tzi,core::datetime const& dt);
}
#endif // timezone_h__

//timezone.cpp

#include <utility/timezone.h>
#include "utility/macroDef.h"
#include "core/string/cstringex.h"
#include "utility/registerKey.h"
#include "utility/algorithm.h"
#include "utility/globalFunctions.h"


namespace Timezone
{
core::cstringexconst TZI_DisplayName= L"Display";
core::cstringexconst TZI_StandardName= L"Std";
core::cstringexconst TZI_DaylightName= L"Dlt";
core::cstringexconst TZI_TZI= L"TZI";


#ifdef UNDER_CE
core::cstringex const TZI_Key = L"Time Zones";
#else
core::cstringex const TZI_Key = L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones";
#endif // UNDER_CE


/////////////////////////////////////////////////////////////////////////////////////////////////////////


bool InitTimeZoneList(core::cvector<TimezoneInfo>& arrTZI);
core::cvector<TimezoneInfo> gs_TimeZoneList;
InitRunFunc1(InitTimeZoneList,gs_TimeZoneList);


bool InitTimeZoneList(core::cvector<TimezoneInfo>& arrTZI) 
{
struct tagTZREG {
LONG Bias;
LONG StandardBias;
LONG DaylightBias;
SYSTEMTIME StandardDate;
SYSTEMTIME DaylightDate;
} regTZI={0}; 
Static_Assert(sizeof(tagTZREG)==44); 

Util::CRegistry reg(HKEY_LOCAL_MACHINE);
core::cvector<core::cstringex> tzNames;
reg.listSubKeys(TZI_Key,tzNames);
if (tzNames.size()==0)
{
return false;
}


core::cstringex parentKeyPath = TZI_Key + L"\\";


TimezoneInfo tzi;
ULONG nBytes = sizeof(tagTZREG);
core::cstringexdisplayName;
core::cstringexstandardName;
core::cstringexdaylightName;
for (core::cvector<core::cstringex>::const_iterator it=tzNames.begin();it != tzNames.end();it++)
{
if (reg.open(parentKeyPath + *it))
{
bool bRet = reg.readStringValue(TZI_DisplayName,tzi.m_displayName);
bRet &=reg.readStringValue(TZI_StandardName,standardName);
bRet &=reg.readStringValue(TZI_DaylightName,daylightName);
bRet &=reg.readBinaryValue(TZI_TZI,(unsigned char *)(&regTZI),nBytes);


ASSERT_AND_LOG(bRet);
if (bRet)
{
tzi.m_tzi.Bias= regTZI.Bias;
tzi.m_tzi.DaylightBias= regTZI.DaylightBias;
tzi.m_tzi.DaylightDate= regTZI.DaylightDate;
tzi.m_tzi.StandardBias= regTZI.StandardBias;
tzi.m_tzi.StandardDate= regTZI.StandardDate;


wsprintf(tzi.m_tzi.StandardName,L"%s",standardName);
wsprintf(tzi.m_tzi.DaylightName,L"%s",daylightName);


arrTZI.push_back(tzi);
}
}
}
UtilExt::sort(arrTZI,&TimezoneInfo::m_tzi,&TIME_ZONE_INFORMATION::Bias,true,&UtilExt::lesser<LONG,LONG>);
return arrTZI.size() != 0;
}




TimezoneInfo const& getTimeZone( unsigned int idx )
{
ASSERT_AND_LOG(gs_TimeZoneList.size()>0);
ASSERT_AND_LOG(idx<gs_TimeZoneList.size());
return gs_TimeZoneList[idx];
}


core::cvector<TimezoneInfo> const& getTimeZoneList()
{ 
ASSERT_AND_LOG(gs_TimeZoneList.size()>0);


return gs_TimeZoneList;
}


bool isDaylightSavingAvailable( TIME_ZONE_INFORMATION const& tzi)
{
return 0!=memcmp(&tzi.DaylightDate,&tzi.StandardDate,sizeof(SYSTEMTIME));
}


bool isInDaylightSavingPeriod( TIME_ZONE_INFORMATION const& tzi,core::datetime const& dt )
{
ASSERT_AND_LOG(isDaylightSavingAvailable(tzi));
SYSTEMTIME stdDt=tzi.StandardDate;
SYSTEMTIME dltDt=tzi.DaylightDate;
SYSTEMTIME curDt = dt.getSystemTime();
stdDt.wYear = curDt.wYear;
dltDt.wYear = curDt.wYear;


__time64_t std_t = core::datetime(stdDt).getTime_t();
__time64_t dlt_t = core::datetime(dltDt).getTime_t();
__time64_t cur_t = core::datetime(curDt).getTime_t();


if (dlt_t>std_t)
{
return !(cur_t>= std_t && cur_t <dlt_t);
}
else
{
return cur_t >= dlt_t && cur_t <= std_t;
}
}


bool setTimeZone( TIME_ZONE_INFORMATION const& tzi, bool bDaylightSaving )
{ 
SetTimeZoneInformation(&tzi);
#ifdef UNDER_CE
SetDaylightTime(bDaylightSaving?1:0);
#endif // UNDER_CE


RegFlushKey(HKEY_LOCAL_MACHINE);
return true;
}


core::datetime getLocalDatetime( core::datetime utc0DT,TIME_ZONE_INFORMATION const& tzi )
{ 
//WinCE doesn't support SystemTimeToTzSpecificLocalTime, we have to do it by myself
//UTC = local time + bias
long bias = tzi.Bias;
core::datetime localDatetime(utc0DT);
if (bias<0)
{
localDatetime.addSeconds(-bias*60);
}
else
{
localDatetime.substractSeconds(bias*60);
}
return localDatetime;
}


core::datetime getUTC0Datetime( core::datetime localDT,TIME_ZONE_INFORMATION const& tzi )
{
//WinCE doesn't support TzSpecificLocalTimeToSystemTime, we have to do it by myself
long bias = tzi.Bias;
core::datetime utc0DT(localDT);
if (bias<0)
{
utc0DT.substractSeconds(-bias*60);
}
else
{
utc0DT.addSeconds(bias*60);
}
return utc0DT;
}


bool strHasStr(core::cstringex& src,core::cstringex& dst)
{
return src.find(dst)!=-1;
}


TimezoneInfo const* lookupTimeZone( core::cstringex const& tziUniqueString )
{
ASSERT_AND_LOG(gs_TimeZoneList.size()!=0);
        using namespace UtilExt;


        return findImpl(makeDataSet(gs_TimeZoneList),makeFinder(core::cstringex(tziUniqueString),MMP(&TimezoneInfo::m_displayName),strHasStr));
}
}