I have a DbGrid showing a database of products.  In one of the columns the
current stock is displayed. I want to color the font red if the number of
items on stock is below a certain value, so it attracts the users attention.

I wrote an OnDrawColumnCell event to handle it:

     begin
       if (StrToFloat(DbGrid1.Columns[5].field.displaytext))<50 then
           DbGrid1.Columns[5].font.color:=clRed
       else
           DbGrid1.Columns[5].font.color:=clBlack;
     end;

But it is no good, the column flickers and the coloring happens always one
row to late!

Here are my 2 questions:

1) Is DbGrid1.Columns.Field.DisplayText the correct way to querry the value?
(It is a calculated field I want to check, so DbGrid1.Fields[n] is out the
question, the GetFieldValue(n) works only with TCustomDbGrid.)

2) It is the right event to do the coloring.

Further you must set DefaultDrawing to false and call DefaultDrawColumnCell at
the end of the event handler. Your event handler should look like this:

Hello !

On Mon, 23 Feb 1998 22:37:24 +0100, Juergen Hemelt

begin
  if (Column.FieldName = 'Inventory') then
    if (Column.Field.AsFloat < 50) then
      (Sender as TDBGrid).Canvas.Font.Color := clRed;

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

or if you want the whole row to be colored red then

begin
  if (Column.Field.DataSet.FieldByName('Inventory').AsFloat < 50) then
    (Sender as TDBGrid).Canvas.Font.Color := clRed;

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