请教个有关时间比较的问题

Question

procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
    if (Query2.FieldByName('a').AsDateTime <now  or Query2.FieldByName('b').AsDateTime<now or Query2.FieldByName('c').AsDateTime<now) then
      begin
        DBGrid1.Canvas.Font.Color:= clred;
      end
      else
      begin
        if  Query2.FieldByName('d').AsString='mm'  then
        begin
        DBGrid1.Canvas.Font.Color:= clblue;
        end
        else
        begin
        DBGrid1.Canvas.Font.Color:= clwindowText;
        end     end;
   dbGrid1.DefaultDrawColumnCell(rect, datacol, column, state);
end;调试会出错 

Answer 1

if Query2.Active then
  if (Query2.FieldByName('a').AsDateTime <now)  or (Query2.FieldByName('b').AsDateTime <now) or (Query2.FieldByName('c').AsDateTime <now) then ... 

Answer 2

        end;     end; 

Answer 3

procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect; 
  DataCol: Integer; Column: TColumn; State: TGridDrawState); 
begin 
    if (Query2.FieldByName('a').AsDateTime <now()) or (Query2.FieldByName('b').AsDateTime <now()) or 
        (Query2.FieldByName('c').AsDateTime <now() ) then 
    begin 
      DBGrid1.Canvas.Font.Color:= clred; 
    end  else 
    begin 
      if Query2.FieldByName('d').AsString='mm'  then 
      begin 
        DBGrid1.Canvas.Font.Color:= clblue; 
      end   else 
      begin 
        DBGrid1.Canvas.Font.Color:= clwindowText; 
      end 
    end; 
  dbGrid1.DefaultDrawColumnCell(rect, datacol, column, state); 
end; 

Answer 4

建议你，不要用这种比较方法，怎么着也要把时间格式化一下。用Datediff函数比较。

Answer 5

if () or () or () then