C#委托和事件实例
// 热水器public class Heater
{
private int temperature;
public string type = "RealFire 001"; // 添加型号作为演示
public string area = "China Xian"; // 添加产地作为演示
//声明委托
public delegate void BoiledEventHandler(Object sender, BoiledEventArgs e);
public event BoiledEventHandler Boiled; //声明事件
// 定义BoiledEventArgs类,传递给Observer所感兴趣的信息
public class BoiledEventArgs : EventArgs
{
public readonly int temperature;
public BoiledEventArgs(int temperature)
{
this.temperature = temperature;
}
}
// 可以供继承自 Heater 的类重写,以便继承类拒绝其他对象对它的监视
protected virtual void OnBoiled(BoiledEventArgs e)
{
if (Boiled != null)
{ // 如果有对象注册
Boiled(this, e); // 调用所有注册对象的方法
}
}
// 烧水。(第一次调用该方法)
public void BoilWater()
{
for (int i = 0; i <= 100; i++)
{
temperature = i;
if (temperature > 98)
{
//建立BoiledEventArgs 对象。
BoiledEventArgs e = new BoiledEventArgs(temperature);
OnBoiled(e); // 调用 OnBolied方法(触发事件的方法)
}
}
}
}
// 警报器
public class Alarm
{
public void MakeAlert(Object sender, Heater.BoiledEventArgs e)
{
Heater heater = (Heater)sender;
//访问 sender 中的公共字段
Console.WriteLine("Alarm:{0} - {1}: ", heater.area, heater.type);
Console.WriteLine("Alarm: 嘀嘀嘀,水已经 {0} 度了:", e.temperature);
Console.WriteLine();
}
}
// 显示器
public class Display
{
public static void ShowMsg(Object sender, Heater.BoiledEventArgs e)
{ //静态方法
Heater heater = (Heater)sender;
Console.WriteLine("Display:{0} - {1}: ", heater.area, heater.type);
Console.WriteLine("Display:水快烧开了,当前温度:{0}度。", e.temperature);
Console.WriteLine();
}
}
class Program
{
public static void Main()
{
Heater heater = new Heater();
Alarm alarm = new Alarm();
heater.Boiled += alarm.MakeAlert; //注册方法
heater.Boiled += (new Alarm()).MakeAlert; //给匿名对象注册方法
heater.Boiled += new Heater.BoiledEventHandler(alarm.MakeAlert); //也可以这么注册
heater.Boiled += Display.ShowMsg; //注册静态方法
heater.BoilWater(); //烧水,会自动调用注册过对象的方法(按照顺序调用)
}
} --------------------编程问答--------------------
楼主在干什么? --------------------编程问答-------------------- 开水壶的嵌入式程序~ --------------------编程问答-------------------- --------------------编程问答-------------------- 举一个关于委托及事件的应用... --------------------编程问答-------------------- 虽然很老,但是很经典 --------------------编程问答-------------------- 非常经典实用的例子 --------------------编程问答-------------------- 这次不收衣服了?
改烧水了
补充:.NET技术 , 非技术区