TdxSpreadSheetHistory.BeginAction(TdxSpreadSheetHistoryActionClass) Method

Locks the action history and starts to record a series of document changes as a single history action.

Declaration

delphi

procedure BeginAction(AActionClass: TdxSpreadSheetHistoryActionClass);

Parameters

Name	Type
AActionClass	TdxSpreadSheetHistoryActionClass

Remarks

A spreadsheet control records every change to the opened document into the undo action list if the history functionality is enabled. If you make a large series of changes programmatically, the resulting action list can occupy much memory. Enclose your code between BeginAction and EndAction procedure calls to record all the changes it makes as a single history action. Pass a reference to the required history action class as the AActionClass parameter.

For instance, the following code populates range 10 by 10 cells with random integers from 0 to 1000 and records these changes as a single cell edit action. You can undo these changes in a single step rather than in 100 steps.

Delphi
C++

delphi

var
  ATableView: TdxSpreadSheetTableView;
  ACell: TdxSpreadSheetCell;
  I, J: Integer;
begin
  ATableView := dxSpreadSheet1.ActiveSheetAsTable;
  Randomize;
  dxSpreadSheet1.History.BeginAction(TdxSpreadSheetHistoryEditCellAction);
  ATableView.BeginUpdate;
  for I := 0 to 9 do
    for J := 0 to 9 do
    begin
      ACell := ATableView.CreateCell(I, J);
      ACell.AsInteger := Random(1000);
    end;
  ATableView.EndUpdate;
  dxSpreadSheet1.History.EndAction;
end;

cpp

TdxSpreadSheetTableView *ATableView;
  TdxSpreadSheetCell *ACell;
  ATableView = dxSpreadSheet1->ActiveSheetAsTable;
  Randomize();
  dxSpreadSheet1->History->BeginAction(__classid(TdxSpreadSheetHistoryEditCellAction);
  ATableView->BeginUpdate();
  for(int I = 0; I < 10; I++)
    for(int J = 0; J < 10; J++)
    {
      ACell = ATableView->CreateCell(I, J);
      ACell->AsInteger = Random(1000);
    }
  ATableView->EndUpdate();
  dxSpreadSheet1->History->EndAction();

Ensure that an EndAction procedure call follows every BeginAction call, even if an exception occurs. Otherwise – the action lists remain locked and cannot record new document changes.