StringGrid排序函数
推荐高速排序函数（在StringGrid里加上5000行试试就知道它的效率了）【来自wyb_star】
【这个东西很强劲的，感谢 wyb_Star 提供】

高速排序函数（在StringGrid里加上5000行试试就知道它的效率了）
procedure Quicksort(Grid:TStringGrid; var List:array of integer;
min, max,sortcol,datatype: Integer);
{List is a list of rownumbers in the grid being sorted}
var
med_value : integer;
hi, lo, i : Integer;

function compare(val1,val2:string):integer;
var
int1,int2:integer;
float1,float2:extended;
errcode:integer;
begin
case datatype of
0: result:=ANSIComparetext(val1,val2);
1: begin
int1:=strtointdef(val1,0);
int2:=strtointdef(val2,0);
if int1>int2 then result:=1
else if int1<int2 then result:=-1
else result:=0;
end;

2: begin
val(val1,float1,errcode);
if errcode<>0 then float1:=0;
val(val2,float2,errcode);
if errcode<>0 then float2:=0;
if float1>float2 then result:=1
else if float1<float2 then result:=-1
else result:=0;
end;
else result:=0;
end;
end;

begin
{If the list has <= 1 element, it's sorted}
if (min >= max) then Exit;
{Pick a dividing item randomly}
i := min + Trunc(Random(max - min + 1));
med_value := List[i];
List[i] := List[min]; { Swap it to the front so we can find it easily}
{Move the items smaller than this into the left
half of the list. Move the others into the right}
lo := min;
hi := max;
while (True) do
begin
// Look down from hi for a value < med_value.
while compare(Grid.cells[sortcol,List[hi]]
,grid.cells[sortcol,med_value])>=0 do
(*ANSIComparetext(Grid.cells[sortcol,List[hi]]
,grid.cells[sortcol,med_value])>=0 do*)
begin
hi := hi - 1;
if (hi <= lo) then Break;
end;
if (hi <= lo) then
begin {We're done separating the items}
List[lo] := med_value;
Break;
end;

// Swap the lo and hi values.
List[lo] := List[hi];
inc(lo); {Look up from lo for a value >= med_value}
while Compare(grid.cells[sortcol,List[lo]],
grid.cells[sortcol,med_value])<0 do
begin
inc(lo);
if (lo >= hi) then break;
end;
if (lo >= hi) then
begin {We're done separating the items}
lo := hi;
List[hi] := med_value;
break;
end;
List[hi] := List[lo];
end;
{Sort the two sublists}
Quicksort(Grid,List, min, lo - 1,sortcol,datatype);
Quicksort(Grid,List, lo + 1, max,sortcol,datatype);
end;

//datatype 0：按字符排序 1：按整型排序 2：按浮点型排序
procedure Sortgrid(Grid : TStringGrid; sortcol,datatype:integer);
var
i : integer;
tempgrid:tstringGrid;
list:array of integer;
begin
screen.cursor:=crhourglass;
tempgrid:=TStringgrid.create(nil);
with tempgrid do
begin
rowcount:=grid.rowcount;
colcount:=grid.colcount;
fixedrows:=grid.fixedrows;
end;
with Grid do
begin
setlength(list,rowcount-fixedrows);
for i:= fixedrows to rowcount-1 do
begin
list[i-fixedrows]:=i;
tempgrid.rows[i].assign(grid.rows[i]);
end;
quicksort(Grid, list,0,rowcount-fixedrows-1,sortcol,datatype);
for i:=0 to rowcount-fixedrows-1 do
begin
rows[i+fixedrows].assign(tempgrid.rows[list[i]])
end;
row:=fixedrows;
end;
tempgrid.free;
setlength(list,0);
screen.cursor:=crdefault;
end;

使用方法：
procedure TForm1.StringGrid1MouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
var
c:integer;
w:integer;
Grid:TStringGrid;
begin
Grid := Sender as TStringGrid;
with Grid do
if y<=rowheights[0] then
begin
c:=0;
w:=colwidths[0];
while (c<colcount) and (w<=x) do
begin
inc(c);
w:=w+colwidths[c]+gridlinewidth;
end;
sortgrid(Grid,c,0);
end;

end;