Delphi - descending sort of string grid rows, sorting by 1 column - sorting

Question

I've run into a bit of a wall with my sorting, I managed to sort the rows of my string grid from smallest to largest but now I'm not sure how to sort it in descending order. I've tried using the code I used from the other sort and I only changed the 2nd last loop in the code to see if I can read from the bottom of the TStringList, but it hasn't worked and only takes one row from the list and duplicates it into the rest of the rows. Is there perhaps a way to reverse read a TStringList after sorting?
Code I used for the other sort I have and tried to implement for this sort (only changed the 2nd last loop):
procedure TfrmPuntehou.SortLTSGrid(var grid: TStringGrid; columntotal: Integer);
const
separator = ',';
var
iCount,i,j,k,iPos:integer;
TheList:TStringList;
sString,sTempString:string;
m: Integer;
o: Integer;
begin
//procedure to sort from large to small values
//get row amount
iCount:=grid.RowCount-1;
//create list
TheList:=TStringList.Create;
TheList.Sorted:=False;
//start of try..finally block
try
begin
//fill the list
for i := 1 to (iCount - 1) do
begin
TheList.Add(grid.Rows[i].Strings[columntotal]+separator+grid.Rows[i].Text);
end;
//sort the list
TheList.Sort;
for k := 1 to TheList.Count do
begin
//take the line of the list and put it in a string var
sString:= TheList.Strings[(k-1)];
//get separator pos in that string
iPos:=AnsiPos(separator,sString);
sTempString:='';
//remove separator and the column text at the front of the string
sTempString:=Copy(sString,(iPos+1),Length(sString));
TheList.Strings[(k-1)]:= '';
TheList.Strings[(k-1)]:= sTempString;
end;
//fill the grid
for j:= (iCount - 1) downto 1 do
begin
for o := 1 to (iCount - 1) do
begin
grid.Rows[j].Text := TheList.Strings[(o-1)] ;
end;
end;
//fill the row numbers
for m := 1 to iCount do
begin
grid.Cells[0,m]:= IntToStr(m);
end;
end;
finally
TheList.Free;
end;
//end of try..finally block
end;
Thanks in advance for the help!Kind RegardsPrimeBeat

Answer 1

Use TStringList.CustomSort to sort the list using a specific method for comparison.
The specification for the comparer is given here.
Example:
function Compare1( // Normal alphanum sort
List : TStringList;
Index1 : Integer;
Index2 : Integer) : Integer;
begin
if List[Index1] = List[Index2] then
Result := 0
else if List[Index1] < List[Index2] then
Result := -1
else
Result := 1;
end;
function Compare2( // Reverse alphanum sort
List : TStringList;
Index1 : Integer;
Index2 : Integer) : Integer;
begin
if List[Index1] = List[Index2] then
Result := 0
else if List[Index1] < List[Index2] then
Result := 1
else
Result := -1;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
SList : TStringList;
S : String;
begin
SList := TStringList.Create;
try
SList.Add('Pierre');
SList.Add('Albert');
SList.Add('Paul');
SList.Add('Jean');
SList.Add('Simon');
Memo1.Lines.Add('=== Compare1 ===');
SList.CustomSort(Compare1);
for S in SList do
Memo1.Lines.Add(S);
Memo1.Lines.Add('=== Compare2 ===');
SList.CustomSort(Compare2);
for S in SList do
Memo1.Lines.Add(S);
finally
SList.Free;
end;
end;