TMemo/ja

procedure TForm1.Button1Click(Sender: TObject);
var
  myStringList: TStringList;
begin
  myStringList:=TStringList.Create;               //StringListを作る
  myStringList.Add('This is the first line.');    //１行加える
  myStringList.Add('This is the second line.');
  myStringList.Add('This is the third line.');
  myStringList.Add('etc.');
  Memo1.Lines.Assign(myStringList);               //テキスト内容を割り当てる
  myStringList.Free;                              //StringListを解放
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Memo1.Lines.Clear;                              //Memo1のすべての行を削除
  Memo1.Lines.Add('This is the first line.');     //1行加える。
  Memo1.Lines.Add('This is the second line.');
  Memo1.Lines.Add('This is the third line.');
  Memo1.Lines.Add('etc.');
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  ShowMessage(Memo1.Lines[2]);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  ShowMessage(Memo1.SelText); 
end;

// FindInMemo: 探す文字列が見つかった場所を返す
function FindInMemo(AMemo: TMemo; AString: String; StartPos: Integer): Integer;
begin
  Result := PosEx(AString, AMemo.Text, StartPos);
  if Result > 0 then
  begin
    AMemo.SelStart := UTF8Length(PChar(AMemo.Text), Result - 1);
    AMemo.SelLength := Length(AString);
    AMemo.SetFocus;
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
const
  SearchStr: String = '';                     // 探す文字列
  SearchStart: Integer = 0;                   // 探す文字列の最後の場所
begin
  if SearchStr <> Edit1.Text then begin       // Falls sich der zu suchende String geändert hat
    SearchStart := 0;
    SearchStr := Edit1.Text;
  end;
  SearchStart := FindInMemo(Memo1, SearchStr, SearchStart + 1);

  if SearchStart > 0 then
    Caption := 'Found at position['+IntToStr(SearchStart)+']!'
  else
    Caption := 'No further finds!';
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  if SaveDialog1.Execute then
    Memo1.Lines.SaveToFile(SaveDialog1.FileName);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  if OpenDialog1.Execute then
    Memo1.Lines.LoadFromFile(OpenDialog1.FileName);
end;