Delphi / C++ Builder - Set active/selected row color in TDBGrid

Question

I want to set the background color of the active/selected row in a TDBGrid control.

Using the OnDrawColumnCell event:

1) The following code will work if DBGrid has the option dgMultiSelect, if not, nothing happens:

if ( grid->SelectedRows->CurrentRowSelected ) {
    grid->Canvas->Brush->Color = clBlue;
} 

2) The following code will work if DBGrid has the option dgRowSelect, if not, only the selected CELL, not the entire row, will be colored:

if ( State.Contains(gdSelected) ) {
    grid->Canvas->Brush->Color = clBlue;
} 

How could I color the entire active/selected row without using dgRowSelect or dgMultiSelect?

Answer 1

From OnDrawColumnCell:

An OnDrawColumnCell event handler can call the DefaultDrawColumnCell method to instruct the data-aware grid to write the data value in the cell.

Use DefaultDrawColumnCell like this. This is Delphi code but you may convert it easy.

procedure TForm1.DBGridDrawColumnCell(Sender: TObject;const Rect: TRect; 
DataCol: Integer; Column: TColumnEh;State: TGridDrawState);
begin
.....    
  DBGrid.Canvas.Brush.Color := clBlue;
  DBGrid.DefaultDrawColumnCell(Rect,DataCol,Column,State);
....

Update

How to paint the DBGrid active row, without setting dgRowSelect or dgMultiSelect.

1. We need to get the top position of current row.

Define a class that inheritant of TDBGrid to make CellRect, Col and Row public:

type
  TMyDBGrid = class(TDBGrid)
  public
    function CellRect(ACol, ARow: Longint): TRect;
    property Col;
    property Row;
  end;

function TMyDBGrid.CellRect(ACol, ARow: Longint): TRect;
begin
  Result := inherited CellRect(ACol, ARow);
end;

Now we can check the top of current cell in OnDrawColumnCell event :

procedure TMainForm.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);

var Col,Row : Integer;
begin
  col := TMyDbGrid(DBGrid1).Col;
  row := TMyDbGrid(DBGrid1).Row;
  if (Rect.Top = TMyDBGrid(DBGrid1).CellRect(Col,Row).Top) and
                   (not (gdFocused in State) or not Focused) then
    DBGrid1.Canvas.Brush.Color := clBlue;

  DBGrid1.DefaultDrawColumnCell(Rect,DataCol,Column,State);
 end;