/* 状态模式，其实就是减少判断分支 */
static void Main(string[] args)
{
Weather weather = new Weather(new Low());
weather.Up();
weather.Up();
weather.Up();
Console.Read();
}
public override void Up(Weather weather)
{
Console.WriteLine("低温");
weather.temperatureState = new Normal();
}
public override void Up(Weather weather)
{
Console.WriteLine("高温");
}
public override void Up(Weather weather)
{
Console.WriteLine("正常");
weather.temperatureState = new Hot();
}
public abstract void Up(Weather weather);