说明：  关于C#中timer类 在C#里关于定时器类就有3个 1.定义在System.Windows.Forms里 2.定义在System.Threading.Timer类里 3.定义在System.Timers.Timer类里
(The timer on the C# class in C#, there are three categories on the timer 1. Defined in the System.Windows.Forms in 2. System.Threading.Timer class definition in 3. The definition of class in the System.Timers.Timer)