Sorting StringGrid by two (or more) columns
lazarus / 61-Beginners

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TomTom · 2022-10-03 07:04

I have something like this in StringGrid. I need to sort it firstly by
second column and then by first column.
Sorting by one column is easy but I can't figure out how to sort a
grid by more than one.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i -----------
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B:\OLDCRC konwersja\53\636\0\1\8\2_org.jpg  | 2012.11.16
22:11:08.527420630B:\OLDCRC konwersja\53\636\0\1\8\3_org.jpg  |
2012.11.16 22:11:08.527420630B:\OLDCRC
konwersja\53\636\0\1\8\6_org.jpg  | 2012.11.16
22:11:08.527420630B:\OLDCRC konwersja\53\636\0\1\8\5_org.jpg  |
2012.11.16 22:11:08.527420630B:\OLDCRC
konwersja\53\636\0\1\8\4_org.jpg  | 2012.11.16
22:11:08.527420630B:\OLDCRC konwersja\53\636\0\1\8\10_org.jpg |
2012.11.16 22:11:09.527420235B:\OLDCRC
konwersja\53\636\0\1\8\11_org.jpg | 2012.11.16
22:11:09.527420235B:\OLDCRC konwersja\53\636\0\1\8\7_org.jpg  |
2012.11.16 22:11:09.527420235B:\OLDCRC
konwersja\53\636\0\1\8\8_org.jpg  | 2012.11.16
22:11:09.527420235B:\OLDCRC konwersja\53\636\0\1\8\9_org.jpg  |
2012.11.16 22:11:09.527420235B:\OLDCRC
konwersja\53\636\0\1\8\12_org.jpg | 2012.11.16
22:11:09.527420235B:\OLDCRC konwersja\53\636\0\1\8\17_org.jpg |
2012.11.16 22:11:10.527419840B:\OLDCRC
konwersja\53\636\0\1\8\16_org.jpg | 2012.11.16
22:11:10.527419840B:\OLDCRC konwersja\53\636\0\1\8\15_org.jpg |
2012.11.16 22:11:10.527419840B:\OLDCRC
konwersja\53\636\0\1\8\13_org.jpg | 2012.11.16 22:11:10.527419840-----
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Josh · 2022-10-03 07:17

hi i dont use stringgrid much, but a couple of ideas
1 sort data by 2nd column then from that result sort by 1st column
2 join column 1 data and column 2 data together and sort that.

ps with filenames from a drive they will all be unique in windows,so
sorting by name should be all that is required.

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TomTom · 2022-10-03 07:45

Well, this is part of my program for restoring proper file order.
Those files have wrong names (messed by someone else who used third
party software for renaming). I'm asking how to sort stringgrid by two
columns because in my program when user is changing the date of file
(well just a text) then program sorts whole StringGrid to show the
changes, and that is ok. But, there is small problem. Every time
sorting order is different... For example, I have something like that:

B:\OLDCRC konwersja\53\636\0\1\8\2_org.jpg   2012.11.16
22:11:08.527420630
B:\OLDCRC konwersja\53\636\0\1\8\3_org.jpg   2012.11.16
22:11:08.527420630
B:\OLDCRC konwersja\53\636\0\1\8\6_org.jpg   2012.11.16
22:11:08.527420630
B:\OLDCRC konwersja\53\636\0\1\8\5_org.jpg   2012.11.16
22:11:08.527420630
B:\OLDCRC konwersja\53\636\0\1\8\4_org.jpg   2012.11.16
22:11:08.527420630

I change the date of file 6_org.jpg from 2012.11.16 22:11:08.527420630
to 2012.11.16 22:11:08.527420635 and then StringGrid is being sorted
by date Column. As expected file is positioned at last row. But... the
roder of other files is also changed. For example 2_org.jpg and
3_org.jpg switch their places. Even when I ... Never mind...
 While writing this I realized that I need to change my question...

It should be... How to sort stringGrid without changing order of
sorting, or how to sort it, always in ascending order .

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wp · 2022-10-03 08:46

Use a special handler for the OnCompareCells event. It is called when
sorting is requested. Assuming that the filenames are in column 0 and
the date/times in column 1, this works for me:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.StringGrid1CompareCells(Sender: TObject; ACol, ARow, BCol, 
BRow: Integer; var Result: integer);begin  if StringGrid1.SortColumn =
1 then  begin    Result := CompareStr(StringGrid1.Cells[ACol, ARow],
StringGrid1.Cells[BCol, BRow]);    if Result = 0 then      Result :=
CompareStr(StringGrid1.Cells[0, ARow], StringGrid1.Cells[0, BRow]);  
if StringGrid1.SortOrder = soDescending then      Result := -Result; 
end;end; Please note that "10_org.jpg" is "smaller" than "7_org.jpg"
because "1" is smaller than "7" and "0" is smaller than "_"! However,
you probably want to sort by the filenames numerically. Therefore, you
must extract the numbers from the filenames (e.g. 7 from "B:\OLDCRC
konwersja\53\636\0\1\8\7_org.jpg", and compare them as numbers rather
than strings.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.StringGrid1CompareCells(Sender: TObject; ACol, ARow, BCol, 
BRow: Integer; var Result: integer);var  sa, sb: String;  na, nb:
Integer;begin  if StringGrid1.SortColumn = 1 then  begin    Result :=
CompareStr(StringGrid1.Cells[ACol, ARow], StringGrid1.Cells[BCol,
BRow]);    if Result = 0 then    begin      sa :=
ExtractFileName(StringGrid1.Cells[0, ARow]);      sb :=
ExtractFileName(StringGrid1.Cells[0, BRow]);      SetLength(sa,
pos('_', sa)-1);      SetLength(sb, pos('_', sb)-1);      na :=
StrToInt(sa);      nb := StrToInt(sb);      Result := na-nb;    end; 
 if StringGrid1.SortOrder = soDescending then      Result := -Result; 
end;end;
See attachment. (Sort by clicking in the column header)

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paweld · 2022-10-03 09:03

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Button1Click(Sender: TObject);const  firstcol = 2;  secondcol =
1;var  i, idxfrom, idxto: Integer;  s: String;begin 
StringGrid1.BeginUpdate;  StringGrid1.SortOrder := soAscending;
 //firscol ASC  StringGrid1.SortColRow(True, firstcol);  s := ''; 
idxfrom := 0;  idxto := 0;  StringGrid1.SortOrder := soDescending;
//secondcol DESC  for i := 1 to StringGrid1.RowCount - 1 do  begin   
if s <> StringGrid1.Cells[firstcol, i] then    begin      idxto := i -
1;      if idxfrom < idxto then        StringGrid1.SortColRow(True,
secondcol, idxfrom, idxto);      s := StringGrid1.Cells[firstcol, i]; 
    idxfrom := i;    end;  end;  idxto := i;  if idxfrom < idxto then 
  StringGrid1.SortColRow(True, secondcol, idxfrom, idxto); 
StringGrid1.EndUpdate();end;