在窗体指定位置上闪烁灯，就是画一个红色的圈，再画一个白色的圈

protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
Graphics dc = e.Graphics ;
int i;
i = 2;
while (true)
{
if (2 == i)
{
Pen whitePen = new Pen(Color.White, 2);
dc.DrawEllipse(whitePen, 0, 50, 50, 50);
DateTime start = DateTime.Now;
//最多循环10秒
while ((DateTime.Now - start).Seconds < 2)
{
Application.DoEvents();
}
i = 1;
}
else
{
Pen redPan = new Pen(Color.Red, 2);
dc.DrawEllipse(redPan, 0, 50, 50, 50);
DateTime start = DateTime.Now;
//最多循环10秒
while ((DateTime.Now - start).Seconds < 2)
{
Application.DoEvents();
}
i = 2;
}
}
这段代码有什么问题？