How to Refresh a DBGrid without Losing the Current Row Position

Refresh DBGrid Data - Preserve Row Position

There's DBGrid, there's a dataset and we have a data aware Delphi application :)

When DBGrid is used to display data from a dataset (query or table), by design, after you call Refresh method on a dataset (re-open) (for example, using a DBNavigator), the current row position will be set to zero (first record).

This means that if a user has selected a row somewhere near the bottom of a DBGrid, after a Refresh, the active row will be changed to first row :(

If you have been asking "Is there any way to reopen or refresh a query, leaving the TDBGrid data exactly where it is (without changing the positions)?" Here's one answer to the problem:

Refresh DBGrid Data - Preserve Row Position

Here's a handly little procedure to refresh the content of a DBGrid without losing the row position.

//THackDBGrid = class(TDBGrid)

//refresh datagrid data - preserve row position
procedure Refresh_PreservePosition;
var
  rowDelta: Integer;
  row: integer;
  recNo: integer;
  ds : TDataSet;
begin
  ds := THackDBGrid(DBGrid1).DataSource.DataSet;

  rowDelta := -1 + THackDBGrid(DBGrid1).Row;
  row := ds.RecNo;

  ds.Refresh;

  with ds do
  begin
    DisableControls;
    RecNo := row;
    MoveBy(-rowDelta) ;
    MoveBy(rowDelta) ;
    EnableControls;
  end;
end;

Note the protected hack used here (THackDBGrid) to get the hidden (protected) Row property!

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