[marcoszorrilla]

Código Delphi [-]
 function GridSelectAll(Grid: TDBGrid): Longint; 
 begin 
   Result := 0; 
   Grid.SelectedRows.Clear; 
   with Grid.Datasource.DataSet do 
   begin 
     First; 
     DisableControls; 
     try 
       while not EOF do 
       begin 
         Grid.SelectedRows.CurrentRowSelected := True; 
         inc(Result); 
         Next; 
       end; 
     finally 
       EnableControls; 
     end; 
   end; 
 end;

Un Saludo.