Stringliste zufällig mischen

[Klaus01]

Hallo,

eine kleine Testprozedur:

TStringList.Exchange : 0ms
ListBox1.items.Exchange: 1060ms
Listbox über TStringList mischen: 109ms

Delphi-Quellcode:

procedure TForm1.Button1Click(Sender: TObject);
var
  sl: TStringList;
  i : Integer;
  start : TDateTime;
begin
  sl := TStringList.create;
  for i:=0 to 9999 do
    sl.add(intToStr(i));
  ListBox1.Items.Assign(sl);

  // durchwürfeln

  start := now;
  for i:=sl.count -1 downto (sl.count - 1) div 2 do
    sl.Exchange(i,random(sl.count));
  showMessage('TStringList.Exchange: '+IntToStr(MilliSecondsBetween(now,start)));


  ListBox1.Items.BeginUpdate;
  start := now;
  for i:= ListBox1.Items.Count -1 downto (ListBox1.Items.Count -1) div 2 do
    ListBox1.Items.Exchange(i,random(ListBox1.Items.count));
  showMessage('TListBox.items.Exchange: '+IntToStr(MilliSecondsBetween(now,start)));
  ListBox1.Items.EndUpdate;

  start := now;
  sl.Assign(ListBox1.items);
  for i:=sl.count -1 downto (sl.count - 1) div 2 do
    sl.Exchange(i,random(sl.count));
  ListBox1.Items.Assign(sl);
  showMessage('TListBox über StringList.exchange: '+IntToStr(MilliSecondsBetween(now,start)));

  sl.free;
end;

Grüße
Klaus