C / C++ / MFC

25-Feb-08 2:07

I've been wondering why my recent article 'How To Calculate The Age Of A File' has been getting poor votes. I wondered if the fact that I hadn't used the 'HighPart' and 'LowPart' members of the ULARGE_INTEGER was bad. Then again is my use of the following code bad?

SystemTimeToFileTime (& NowSystemTime, (FILETIME *) & ulSysTime);
SystemTimeToFileTime (&FileSystemTime, (FILETIME *) & ulFileTime);

Since posting my article, I have read 'Date and Time in C++' by RK_2000 and noted that he said

<quote>
Although [FILETIME and LARGE_INTEGER] have the same binary format, the address of all FILETIME structures must begin on a 32 bit boundary whereas the address of all LARGE_INTEGER must begin on 64 bit boundary. So, do not use these interchangeably.

... so this cast I've been using is wrong, then?

In the meantime, I will assume that this is a flaw that people have spotted in my code and rewrite it without this cast.

Thanks for your help,

Ben.

David Crow25-Feb-08 2:19

25-Feb-08 2:19

Ben Aldhouse wrote:
I've been wondering why my recent article 'How To Calculate The Age Of A File' has been getting poor votes.

Because if people have the ability to vote low, then for no other reason, they will. Ignore the vote and move on.

Ben Aldhouse wrote:
...I will assume that this is a flaw that people have spotted in my code...

Doubtful. A truly interested and worthy reader will let you know.

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Ben Aldhouse25-Feb-08 3:10

25-Feb-08 3:10

Thanks, David, for your encouraging reply.

I have tried the code without the cast and I can't get sensible results.

This is what I now have...

WIN32_FIND_DATA FindFileData;
HANDLE hFind;
hFind = FindFirstFile(strPath, &FindFileData);
CString strYears, strMonths, strDays;

SYSTEMTIME stNow;
GetSystemTime(&stNow);
const FILETIME  ftFile = FindFileData.ftCreationTime;

FILETIME ftNow;
ULARGE_INTEGER ulNowTime, ulFileTime, ulAge;

SystemTimeToFileTime (& stNow, &ftNow);

ulNowTime.HighPart = ftNow.dwHighDateTime;
ulNowTime.LowPart = ftNow.dwLowDateTime;
ulFileTime.HighPart = ftFile.dwHighDateTime;
ulFileTime.LowPart = ftFile.dwLowDateTime;

ulAge.HighPart = ulNowTime.HighPart - ulFileTime.HighPart;
ulAge.LowPart = ulNowTime.LowPart - ulFileTime.LowPart;

FILETIME ftAge;
SYSTEMTIME stAge;

ftAge.dwHighDateTime = ulAge.HighPart;
ftAge.dwLowDateTime = ulAge.LowPart;

SystemTimeToFileTime(&stAge,&ftAge);

strYears.Format("%d", stAge.wYear-1601);
strMonths.Format("%d",stAge.wMonth-1);
strDays.Format("%d",stAge.wDay-1);

I'm foxed. I should really take your advice and move on...

Ben.

David Crow25-Feb-08 3:53

25-Feb-08 3:53

What exactly is this code snippet supposed to be doing?

Ben Aldhouse25-Feb-08 5:02

25-Feb-08 5:02

I was trying to find the difference between a file's creation date, the current time and get the resulting data in a useful format. Doing this I was aware of the following warning from the MSDN library

Remarks
    It is not recommended that you add and subtract values from the SYSTEMTIME 
    structure to obtain relative times. Instead, you should 

    -Convert the SYSTEMTIME structure to a FILETIME structure. 
    -Copy the resulting FILETIME structure to a ULARGE_INTEGER structure. 
    -Use normal 64-bit arithmetic on the ULARGE_INTEGER value.

However, I think at this point I was put off because the promised 'HighPart' and 'LowPart' members of ULARGE_INTEGER didn't appear in the autocomplete list on my editor. I have since written in the members anyway and found that they work without any trouble.

Since your last reply I have had a walk around the block and had another look at the code. I discovered that when I was removing some lines whilst taking out the code that used that (FILETIME *)&ULARGE_INTEGER cast, I removed one line I should have left in and edited and left in another line towards the end of the code that should have been removed...

Here is the (now, at last) working code with comments.

Thanks for your encouragement and for showing an interest,

Ben

	WIN32_FIND_DATA FindFileData;
	HANDLE hFind;
	hFind = FindFirstFile(strPath, &FindFileData);
	CString strYears, strMonths, strDays;

	SYSTEMTIME stNow; 
	
//The current time is aquired and stored in SYSTEMTIME format
	GetSystemTime(&stNow);

//The creation time of the file in question is obtained and
//stored in FILETIME format
	const FILETIME  ftFile = FindFileData.ftCreationTime;

//A reference to the current time in FILETIME format is created
	FILETIME ftNow;
	WIN32_FIND_DATA FindFileData;
	HANDLE hFind;
	hFind = FindFirstFile(strPath, &FindFileData);
	CString strYears, strMonths, strDays;

	SYSTEMTIME stNow; 
	
//The current time is aquired and stored in SYSTEMTIME format

	GetSystemTime(&stNow);
	
//The creation time of the file in question is aquired in a FILETIME
//structure then converted inta a SYSTEMTIME structure

	const FILETIME  ftFile = FindFileData.ftCreationTime;
	FILETIME ftNow;
	SystemTimeToFileTime (& stNow, &ftNow);

//The contents of the FILETIME versions of the current time
//and the creation time of the file are now stored in 
//ULARGE_INTEGER structures

	ULARGE_INTEGER ulNowTime, ulFileTime, ulAge;
	ulNowTime.HighPart = ftNow.dwHighDateTime;
	ulNowTime.LowPart = ftNow.dwLowDateTime;
	ulFileTime.HighPart = ftFile.dwHighDateTime;
	ulFileTime.LowPart = ftFile.dwLowDateTime;

//The difference between the current time and the creation time
//of the file can now be created

	ulAge.HighPart = ulNowTime.HighPart - ulFileTime.HighPart;
	ulAge.LowPart = ulNowTime.LowPart - ulFileTime.LowPart;
	
	FILETIME ftAge;
	SYSTEMTIME stAge;

//The ULARGE_INTEGER data can then be copied back to a FILETIME
//structure, this can then be converted to SYSTEMTIME
//which is the convenient format we want our data to be in....

	ftAge.dwHighDateTime = ulAge.HighPart;
	ftAge.dwLowDateTime = ulAge.LowPart;

	FileTimeToSystemTime(&ftAge,&stAge);
	// not SystemTimeToFileTime(&stAge,&ftAge);!

	strYears.Format("%d", stAge.wYear-1601);
	strMonths.Format("%d",stAge.wMonth-1);
	strDays.Format("%d",stAge.wDay-1);

David Crow25-Feb-08 5:09

25-Feb-08 5:09

Have you considered the COleDateTimeSpan class?

Ben Aldhouse25-Feb-08 8:37

To sort shortcut menus programmatically [modified]

25-Feb-08 8:37

Hmm. Looking this up in MSDN I have found out that CTime has constructors for accepting SYSTEMTIME and FILETIME objects.

Looks like I'll be rewriting the code with an even better solution!

Mushtaque Nizamani25-Feb-08 0:49

Mushtaque Nizamani

25-Feb-08 0:49

I have got some shortcuts in "All Programs"-> "Accessories" -> "Test Menu".
“Test Menu” contains some shortcuts of applications and those are not sorted, can anyone please tell how to sort those shortcuts programmatically.
Manually I can do this by using popup menu “Sort by Name” as shown in screen shot.
http://img142.imageshack.us/my.php?image=shortcutsortingquestionbl8.jpg

Best Regards,
Mushq

Mushtaque Ahmed Nizamani
Software Engineer
Ultimus Pakistan

modified on Monday, February 25, 2008 6:57 AM

Re: To sort shortcut menus programmatically

Iain Clarke, Warrior Programmer25-Feb-08 2:17

Iain Clarke, Warrior Programmer

25-Feb-08 2:17

It may well be that there is no way of doing it programmatically. I know many things to do with the start menu are no longer controllable from external programs (ie the pin list) - and that's a good thing. What you want to do might fit in that category.

Is it so bad for the User to do this for themselves - after all they might not want things sorted, if they're used to the layout as it is now.

Iain.

Iain Clarke appearing in spite of being begged not to by ^CPallini.

Re: To sort shortcut menus programmatically

David Crow25-Feb-08 2:43

Re: How to restore dialog?

25-Feb-08 2:43

Have you read through Michael Dunn's Shell Extension articles[^]? This sounds like you simply need to snag on to the contxt menu and select "Sort by Name."

How to restore dialog?

sheetal_0625-Feb-08 0:47

sheetal_06

25-Feb-08 0:47

Hi,

In vista os,when i am trying to open a dialog in application b.exe through another application a.exe the dialog is always appearing on the taskbar.It is not getting displayed on the screen unless you press on the minimized dialog on taskbar.How to change this behaviour?This happens only in vista not in XP.

Thanks,
Sheetal

David Crow25-Feb-08 2:52

Re: How to restore dialog?

25-Feb-08 2:52

Do you have code in place that is initially minimizing the window?

sheetal_0627-Feb-08 17:44

sheetal_06

27-Feb-08 17:44

No code for minimizing.
This behaviour is only in Vista.
In xp it is not getting minimized.It is displayed on top of all other windows.

Re: How to restore dialog?

David Crow28-Feb-08 2:35