定义一个全局变量IsShow:array [0..3] of boolean;
IsShow[0]初始化成true,其他为false;
procedure TForm1.Timer1Timer(Sender: TObject);
var i: integer;
begin
for i:= 0 to 3 do
begin
if IsShow[i] then
begin
dbgrid[(i+3) mod 4].Visiable := false;
dbgrid[i].Visiable := true;
IsShow[i]:= false;
IsShow[(i+1) mod 4]:= false;
end;
end;
end;