Coloring StringGrid from database

[Stygian]

Hello,

I'm looking for a method to color a stringgrid from database. Everytime when a user set a color it will be saved into the database and next time he/she start the application the coloring also loaded.

I cannot load the database into an array. It will be more than 10k rows. Now it's small but it's growing day by day.

Thanks,
Sty

[balazsszekely]

Is there any reason not to use a TDBGrid? Anyway you have the OnDrawCell event for coloring. Just use the forum search, I'm sure somebody already implemented a similar functionality.

[wp]

Use the OnPrepareCanvas event of the DBGrid (I assume that you are talking of a DBGrid, not of a StringGrid - but with the StringGrid the solution would follow the same idea). Set the Brush.Color of the canvas according to the value of the db field:

Code: Pascal  [Select][+][-]

1. procedure TForm1.DBGrid1PrepareCanvas(Sender: TObject; DataCol: Integer; Column: TColumn; AState: TGridDrawState);
2. begin
3.   field: TField;
4.   grid: TDBGrid;
5. begin
6.   if (Sender is TDBGrid) then begin
7.     grid := TDBGrid(Sender);
8.     field := grid.Datasource.Dataset.FieldByName('the_name_of_the_color_field');
9.     grid.Canvas.Brush.Color := field.AsInteger;
10.     // you may also have to adjust the text color (black text on black doesn't look good ;-)
11.     if field.AsInteger > 3*128 then   // bright background --> black text
12.       grid.Canvas.Font.Color := clBlack
13.     else                              // dark background --> white text
14.       grid.Canvas.Font.Color := clWhite;
15.   end;
16. end;

[Stygian]

May i ask when PrepareCanvas execute? After each induvidual rowcount incrase?

Is there any reason not to use a TDBGrid?

I'm using a TTimer which refresh an andon screen from the same database in every 5 sec. And i cannot find an option for Manual Refresh in DBGrind.

Regards,
Sty

[balazsszekely]

@Stygian
I'm using a TTimer which refresh an andon screen from the same database in every 5 sec. And i cannot find an option for Manual Refresh in DBGrind.

Just refresh/reopen the dataset(Query, Table, etc...)

[wp]

May i ask when PrepareCanvas execute? After each induvidual rowcount incrase?

Whenever the grid is repainted. I don't know if the increase of RowCount triggers a repaint of the grid, just call DBGrid1.Invalidate if it does not.

[Stygian]

Dear Everyone,

I dumped the my Stringgrid and changed everything on DBGrid. Now it's working fine.

Thanks everyone for the help,
Sty