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VB Forum / Win API / November 2008sorting files by date/time
Does anybody have a good VB6 sample code that sorts a list of files retrieved using FindFirstFile/FindNextFile by date/time? Regards Peter > Does anybody have a good VB6 sample code that sorts a list of files > retrieved using FindFirstFile/FindNextFile by date/time? > Regards > Peter There is no way (to my knowledge) to tell the FindFirstFile/FindNextFile/FindClose to return files in any order other than what you get. So you need to read them in to an array or a ListView or whatever and then sort them in the usual manner. Dave O. Thanks for your fast answer! What is the best way to sort the files by date/time: Should I create a FILETIME array and use API function CompareFileTime() in my sort routine? Any sample code available? Regards Peter >> Does anybody have a good VB6 sample code that sorts a list of files >> retrieved using FindFirstFile/FindNextFile by date/time? [quoted text clipped - 8 lines] > > Dave O. > Thanks for your fast answer! > What is the best way to sort the files by date/time: > Should I create a FILETIME array and use API function CompareFileTime() in > my sort routine? You could, but why bother, if you put the timestamp into a date variable you can compare them directly in the sort routine. If the data/times are stored as strings you'll need to convert them back to dates for the sort, alternatively you could convert the date/time to doubles and sort on those. It's not all that easy to give exact examples because selecting which routine would be optimum depends on many factors. Dave O. >> Thanks for your fast answer! >> What is the best way to sort the files by date/time: >> Should I create a FILETIME array and use API function CompareFileTime() >> in my sort routine? I just remembered you MUST apply the FileTimeToLocalFileTime API to the FileTime structure before you save the value anywhere, this is because the file stamps are stored in UDT (GMT no summer adjustment) and will need to be adjusted to your locale. Regards Dave O. Thanks, but I think I don't need to use FileTimeToLocalFileTime() just to sort the files by date/time, am I right? Regards Peter >>> Thanks for your fast answer! >>> What is the best way to sort the files by date/time: [quoted text clipped - 8 lines] > Regards > Dave O. > Thanks, but I think I don't need to use FileTimeToLocalFileTime() just to > sort the files by date/time, am I right? You don't. In addition it is not necessary to call CompareFileTime() since a FIILETIME is just an increasing 64 bit number. The call to CompareFileTime() needs more time than a comparison done in you code. If FT_A.dwHighDateTime <> FT_B.dwHighDateTime Then If FT_A.dwHighDateTime >= 0 Then If FT_B.dwHighDateTime >= 0 Then If FT_A.dwHighDateTime > FT_B.dwHighDateTime Then ' A >= 0 / B >= 0 - A > B Else ' A >= 0 / B >= 0 - A < B End If Else ' A >= 0 / B < 0: A < B End If ElseIf FT_B.dwHighDateTime >= 0 Then ' A < 0 / B >= 0: A > B ElseIf FT_A.dwHighDateTime > FT_B.dwHighDateTime Then ' A < 0 / B < 0 - A > B Else ' A < 0 / B < 0 - A < B End If ElseIf FT_A.dwLowDateTime >= 0 Then If FT_B.dwLowDateTime >= 0 Then If FT_A.dwLowDateTime > FT_B.dwLowDateTime Then ' A >= 0 / B >= 0 - A > B Else ' A >= 0 / B >= 0 - A < B End If Else ' A >= 0 / B < 0: A < B End If ElseIf FT_B.dwLowDateTime >= 0 Then ' A < 0 / B >= 0: A > B ElseIf FT_A.dwLowDateTime > FT_B.dwLowDateTime Then ' A < 0 / B < 0 - A > B Else ' A < 0 / B < 0 - A < B End If  Signature---------------------------------------------------------------------- Thorsten Albers albers(a)uni-freiburg.de ---------------------------------------------------------------------- > Thanks, but I think I don't need to use FileTimeToLocalFileTime() just to > sort the files by date/time, am I right? > Regards You might convert the values to the Decimal type which can handle those large numbers. Then you just compare the two (Decimal) values. Conversion might be like: (not tested) Private Function ToDecimal(FileTime As FileTimeType) As Variant Dim hi As Long, lo As Long Dim hx As String hx = Right$("0000000" & Hex(FileTime.Hi), 8) hi = Val("&H" & Left$(hx, 4) & "&") lo = Val("&H" & Right$(hx, 4) & "&") ToDecimal = hi * CDec(65536) + lo hx = Right$("0000000" & Hex(FileTime.Lo), 8) hi = Val("&H" & Left$(hx, 4) & "&") lo = Val("&H" & Right$(hx, 4) & "&") ToDecimal = ToDecimal * CDec(4294967296#) + hi * CDec(65536) + lo End Function The conversion to Hex was used to properly treat the sign bit as used in an unsigned value. Other (all numeric) methods of conversion may be quicker.... LFS Just want to Thank you all for your answers. I solved the problem by using a Function "FileTimetoserial" which creates a Date-Variable out of the FileTime Structure. Then I used these date values in my sort routine. Regards Peter >> Thanks, but I think I don't need to use FileTimeToLocalFileTime() just to >> sort the files by date/time, am I right? [quoted text clipped - 22 lines] > > LFS Peter <peter_l@myrealbox.com> schrieb im Beitrag <gg5m10$cvn$1@mail1.sbs.de>... > Just want to Thank you all for your answers. > I solved the problem by using a Function "FileTimetoserial" which creates a > Date-Variable out of the FileTime Structure. > Then I used these date values in my sort routine. What a completely superfluous performance killer... Signature---------------------------------------------------------------------- Thorsten Albers albers(a)uni-freiburg.de ---------------------------------------------------------------------- You are right. But I found out that I need the filetime in a variable "as date" later in my code so I thought I convert it to date immediately. Regards Peter > Peter <peter_l@myrealbox.com> schrieb im Beitrag > <gg5m10$cvn$1@mail1.sbs.de>... [quoted text clipped - 5 lines] > > What a completely superfluous performance killer... > Does anybody have a good VB6 sample code that sorts a list of files > retrieved using FindFirstFile/FindNextFile by date/time? > Regards > Peter Search for "FindFirstFile" at the following site: http://vbnet.mvps.org The site is for VB6 despite its name. As for comparing times, you can use CompareFileTime, or convert it to a Date data type. For the later, see FileTimeToVBDate() function here: http://vbnet.mvps.org/code/fileapi/fsoapicompare.htm |
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