Question

I am using the TGrid in FM and want users to be able to resize a column, but not re-organise the columns (ie. drag & move the column header). I have tried changing many of the exposed properties (“Locked”, “DragMode”, “EnableDrag” etc…) – but nothing appears to have the desired effect?

In true FM experience; I am guessing that I may have to override the class and change something at the back-end structure; but am unsure what/where – or even if this is feasible?

Sample source wise; you can see the issue if you simply add a TGrid, add a few columns and run.

Many thanks in advance. Ian.

Answer 1

type
  TCustomGridHelper = class helper for TCustomGrid
  public
    /// <summary>
    /// Publish private FHeader from FMX.Grid.TCustomGrid.
    /// </summary>
    function _GetHeader: THeader;
  end;

function TCustomGridHelper._GetHeader: THeader;
begin
  Result := Self.FHeader;
end;

procedure TForm1.Grid1ApplyStyleLookup(Sender: TObject);
var
  I: Integer;
  Header: THeader;
  HeaderItem: THeaderItem;
begin
  Header := Grid1._GetHeader;
  for I := 0 to Header.ChildrenCount - 1 do
  begin
    HeaderItem := Header.Children[I] as THeaderItem;
    HeaderItem.DragMode := TDragMode.dmManual;
  end;
end;