protected virtual void OnThresholdReached(ThresholdReachedEventArgs e)
{
ThresholdReached?.Invoke(this, e);
//等价于
// //创建一个委托变量handler，受EventHandler<ThresholdReachedEventArgs>约束
// //handler获得事件ThresholdReached，handler可以在事件发生时调用事件订阅者方法
// EventHandler<ThresholdReachedEventArgs> handler = ThresholdReached;
////事件订阅者如果不为空
// if (handler != null)
// {
// //间接调用事件订阅者的事件处理器方法。
// handler(this, args);
// }
}
public void Add(int x)
{
total += x;
if (total >= threshold)
{
//阈值到达
//1.事件数据参数实例化args
ThresholdReachedEventArgs args = new ThresholdReachedEventArgs();
//2.事件参数实例args的属性赋值
args.Threshold = threshold;
args.TimeReached = DateTime.Now;
//3.调用触发事件方法，方法名字自定义。约定以On开头。还有时态约束
OnThresholdReached(args);
}
}
//public delegate void EventHandler<TEventArgs>(object sender, TEventArgs e);
static void c_ThresholdReached(object sender, ThresholdReachedEventArgs e)
{
Console.WriteLine("The threshold of {0} was reached at {1}.", e.Threshold, e.TimeReached);
Environment.Exit(0);
}