/// <summary>
///责任链模式 Chain of Responsibility Pattern 亦称： 职责链模式、命令链、CoR、Chain of Command、Chain of Responsibility
/// geovindu,Geovin Du edit
/// </summary>
public enum MessagePriority
{
/// <summary>
/// 正常
/// </summary>
[Description("正常")]
Normal = 1,
/// <summary>
/// 高
/// </summary>
[Description("高")]
High =2
}
public static class geovindu
{
/// <summary>
/// 扩展方法，获得枚举的Description
/// </summary>
/// <param name="value">枚举值</param>
/// <param name="nameInstead">当枚举值没有定义DescriptionAttribute，是否使用枚举名代替，默认是使用</param>
/// <returns>枚举的Description</returns>
public static string GetDescription(this Enum value, Boolean nameInstead = true)
{
Type type = value.GetType();
string name = Enum.GetName(type, value);
if (name == null)
{
return null;
}
FieldInfo field = type.GetField(name);
DescriptionAttribute attribute = System.Attribute.GetCustomAttribute(field, typeof(DescriptionAttribute)) as DescriptionAttribute;
if (attribute == null && nameInstead == true)
{
return name;
}
return attribute?.Description;
}
}
/// <summary>
/// Message class
/// </summary>
public class Message
{
public string Text { get; set; }
public MessagePriority Priority;
/// <summary>
///
/// </summary>
public string Ms { get; set; }
/// <summary>
///
/// </summary>
/// <param name="msg"></param>
/// <param name="priority"></param>
public Message(string msg, MessagePriority priority)
{
this.Text = msg;
this.Priority = priority;
}
/// <summary>
///
/// </summary>
/// <param name="msg"></param>
/// <param name="ms"></param>
public Message(string msg, string ms)
{
this.Text = msg;
this.Ms = ms;
}
}
/// <summary>
/// Abstract class -Receiver
/// The abstract class is chosen to share
/// the common codes across derived classes.
/// </summary>
abstract class Receiver
{
protected Receiver nextReceiver;
//To set the next handler in the chain.
public void NextReceiver(Receiver nextReceiver)
{
this.nextReceiver = nextReceiver;
}
public abstract void HandleMessage(Message message);
}
/// <summary>
/// Fax Error Handler class
/// </summary>
class FaxErrorHandler : Receiver
{
bool messagePassedToNextHandler = false;
public override void HandleMessage(Message message)
{
//Start processing if the error message contains "fax"
if (message.Text.Contains("fax"))
{
Console.WriteLine($" 已处理传真错误处理程序 {message.Ms} 优先排队 : {message.Text}");
//Do not leave now, if the error message contains email too.
if (nextReceiver != null && message.Text.Contains("email"))
{
Console.WriteLine("我已经修复了传真侧的缺陷。现在电子邮件团队需要在这个修复的顶部工作");
nextReceiver.HandleMessage(message);
//We'll not pass the message repeatedly to next handler.
messagePassedToNextHandler = true;
}
}
if (nextReceiver != null && messagePassedToNextHandler != true)
{
nextReceiver.HandleMessage(message);
}
}
}
/// <summary>
/// Email Error Handler class
/// </summary>
class EmailErrorHandler : Receiver
{
bool messagePassedToNextHandler = false;
public override void HandleMessage(Message message)
{
//Start processing if the error message contains "email"
if (message.Text.Contains("email"))
{
Console.WriteLine($"处理电子邮件错误处理程序{message.Ms} 优先排队: {message.Text}");
//Do not leave now, if the error message contains "fax" too.
if (nextReceiver != null && message.Text.Contains("fax"))
{
Console.WriteLine("电子邮件侧缺陷修复。现在传真组需要交叉验证这个修复");
//Keeping the following code here.
//It can be useful if you place this handler before fax error handler
nextReceiver.HandleMessage(message);
//We'll not pass the message repeatedly to the next handler.
messagePassedToNextHandler = true;
}
}
if (nextReceiver != null && messagePassedToNextHandler != true)
{
nextReceiver.HandleMessage(message);
}
}
}
/// <summary>
/// UnknownErrorHandler class
/// </summary>
class UnknownErrorHandler : Receiver
{
public override void HandleMessage(Message message)
{
if (!(message.Text.Contains("fax") || message.Text.Contains("email")))
{
Console.WriteLine("未知错误发生。立即咨询专家");
}
else if (nextReceiver != null)
{
nextReceiver.HandleMessage(message);
}
}
}
调用：
//责任链模式
Console.WriteLine("***责任链模式 Chain of Responsibility Pattern Demo***\n");
//Different handlers
Receiver emailHandler = new EmailErrorHandler();
Receiver faxHandler = new FaxErrorHandler();
Receiver unknownHandler = new UnknownErrorHandler();
faxHandler.NextReceiver(emailHandler);
emailHandler.NextReceiver(unknownHandler);
string du=geovindu.GetDescription(MessagePriority.Normal, true);
string geovin=geovindu.GetDescription(MessagePriority.High, true);
Message msg = new Message("fax.", du); //MessagePriority.Normal
faxHandler.HandleMessage(msg);
msg = new Message("email邮件没有到达目的地.", geovin);
faxHandler.HandleMessage(msg);
msg = new Message("email在电子邮件中，抄送字段总是禁用的.", du);
faxHandler.HandleMessage(msg);
msg = new Message("fax传真没有到达目的地", geovin);
faxHandler.HandleMessage(msg);
msg = new Message("无法登录系统。.", geovin);
faxHandler.HandleMessage(msg);
msg = new Message("fax传真和电子邮件都不能用.", geovin);
faxHandler.HandleMessage(msg);
Console.ReadKey();
输出：
***责任链模式 Chain of Responsibility Pattern Demo*** 已处理传真错误处理程序 正常 优先排队 : fax. 处理电子邮件错误处理程序高 优先排队: email邮件没有到达目的地. 处理电子邮件错误处理程序正常 优先排队: email在电子邮件中，抄送字段总是禁用的. 已处理传真错误处理程序 高 优先排队 : fax传真没有到达目的地 未知错误发生。立即咨询专家 已处理传真错误处理程序 高 优先排队 : fax传真和电子邮件都不能用.
标签：donet,Chain,core,Message,public,nextReceiver,msg,message,HandleMessage From： https://www.cnblogs.com/geovindu/p/16783206.html