窗体上有1个Timer1计时器,1个Shape1形状控件,还有下面程序代码:Dim flag As BooleanPrivate Sub Form_Load() flag = True Timer1.Enabled = True Timer1.Interval = 1000End SubPrivate Sub Timer1_Timer() If flag Then Shape1.Height = Shape1.Height * 2 Shape1.Width = Shape1.Width * 2 Else Shape1.Height = Shape1.Height * 0.5 Shape1.Width = Shape1.Width * 0.5 End If flag = Not flagEnd Sub执行程序所产生的效果是_______________。