TOnWriteCellValueAsString =
procedure (ACell: PCell; AValue: String; var IsPureText: Boolean) of object;
procedure TsWorksheet.WriteCellValueAsString()
..
begin
if ACell = nil then
exit;
DeleteFormula(ACell);
if AValue = '' then
begin
WriteText(ACell, '');
exit;
end;
if Assigned(FOnWriteCellValueAsString) then
begin
IsPureText := False;
FOnWriteCellValueAsString(ACell,AValue, IsPureText);
if IsPureText then
begin
WriteText(ACell, AValue);
exit;
end;
end;
..