Delphi FMX TListBox 大列表慢

Question

我正在将 2,000 个名称加载到 FMX TListBox 中，这花费的时间太长了（比如 35 秒或更长时间）。

这里是测试代码：

procedure TDocWindow.DEBUGAddLotsOfStringsToList;
var
  theTimeAtStart: Integer;
  J: Integer;

begin
  ListBox1.Clear;

  theTimeAtStart := TThread.GetTickCount;

  for J := 1 to 2200 do
    begin
      ListBox1.Items.Add(j.toString);
    end;

  ShowMessage('There were ' + J.ToString + ' strings added to the list in ' + (TThread.GetTickCount - theTimeAtStart).ToString + ' milliseconds.');
end;

TListBox 是否有什么东西让它对于几千个字符串来说太慢了？

Answer 1

使用 BeginUpdate 和 EndUpdate 将我的系统运行时间从 25 秒减少到大约 125 毫秒。

procedure TForm1.Button1Click(Sender: TObject);
var
  theTimeAtStart: Integer;
  J: Integer;
begin
  theTimeAtStart := TThread.GetTickCount;

  ListBox1.Items.BeginUpdate;

  try
    ListBox1.Clear;

    for J := 1 to 2200 do
    begin
      ListBox1.Items.Add(j.ToString());
    end;
  finally
    ListBox1.Items.EndUpdate;
  end;
  ShowMessage('There were ' + J.ToString + ' strings added to the list in ' + (TThread.GetTickCount - theTimeAtStart).ToString + ' milliseconds.');
end;

Delphi FMX TListBox 大列表慢

Delphi FMX TListBox slow with large lists

delphi

firemonkey

tlistbox

delphi-10.4-sydney