之所以把发消息拿出来，完全是因为微软的orchard项目，在这个项目里，将公用的与领域无关的功能模块进行抽象，形成了一个个的组件，这些组件通过引用和注入的方式进行工作，感觉对于应用程序的扩展性上有很大的提高，消息组件的提出是因为它的不固定性，从小方面说，项目模块的发消息的方式可能是不同的，有过模块是email，有的是数据库，有的是短信；而从大的方面说，对于项目与项目来说，它们发消息的方式也可能不同，所以，把它抽象出来，就显得很必要了。
对于一个消息来说，它的行为很固定，即发消息，Send,而考虑到网络阻塞问题，我们也同样提供了异常消息的发送，接口规范如下：
/// <summary>
/// Message Interface
/// Author:Garrett
/// </summary>
public interface IMessageManager
{
/// <summary>
/// Sends a message to a channel using a content item as the recipient
/// </summary>
/// <param name="recipient">A content item to send the message to.</param>
/// <param name="type">A custom string specifying what type of message is sent. Used in even handlers to define the message.</param>
/// <param name="service">The name of the channel to use, e.g. "email"</param>
/// <param name="properties">A set of specific properties for the channel.</param>
void Send(string recipient, MessageType type, string subject, string body); /// <summary>
/// Sends a message to a channel using a set of content items as the recipients
/// </summary>
/// <param name="recipients">A set of content items to send the message to. Only one message may be sent if the channel manages it.</param>
/// <param name="type">A custom string specifying what type of message is sent. Used in even handlers to define the message.</param>
/// <param name="service">The name of the channel to use, e.g. "email"</param>
/// <param name="properties">A set of specific properties for the channel.</param>
void Send(IEnumerable<string> recipients, MessageType type, string subject, string body); /// <summary>
/// Async Sends a message to a channel using a set of content items as the recipients
/// </summary>
/// <param name="recipients">A set of content items to send the message to. Only one message may be sent if the channel manages it.</param>
/// <param name="type">A custom string specifying what type of message is sent. Used in even handlers to define the message.</param>
/// <param name="service">The name of the channel to use, e.g. "email"</param>
/// <param name="properties">A set of specific properties for the channel.</param>
/// <param name="isAsync">is Async</param>
void Send(IEnumerable<string> recipients, MessageType type, string subject, string body, bool isAsync); }
有了规范，就是实现这个规范，我们以Email为例，看一下 Email消息发送的实现代码：
/// <summary>
/// 默认发消息服务
/// </summary>
public class EmailMessageManager : IMessageManager
{ #region Delegate & Event
/// <summary>
/// 加入发送队列中
/// </summary>
/// <param name="context"></param>
public delegate void SendingEventHandler(MessageContext context);
/// <summary>
/// 发送消息
/// </summary>
/// <param name="context"></param>
public delegate void SentEventHandler(MessageContext context);
/// <summary>
/// 加入发送队列中
/// </summary>
public event SendingEventHandler Sending;
/// <summary>
/// 发送消息
/// </summary>
public event SentEventHandler Sent; void OnSending(MessageContext context)
{
if (Sending != null)
Sending(context);
}
void OnSent(MessageContext context)
{
if (Sent != null)
Sent(context);
}
#endregion #region IMessageManager 成员 public void Send(string recipient, MessageType type, string subject, string body)
{
Send(new List<string> { recipient }, type, subject, body);
} public void Send(IEnumerable<string> recipients, MessageType type, string subject, string body)
{
Send(recipients, type, subject, body, false);
} public void Send(IEnumerable<string> recipients, MessageType type, string subject, string body, bool isAsync)
{
if (recipients != null && recipients.Any())
{
using (SmtpClient client = new SmtpClient()
{
Host = MessageManager.Instance.Host,
Port = MessageManager.Instance.Port,
Credentials = new NetworkCredential(MessageManager.Instance.UserName, MessageManager.Instance.Password),
EnableSsl = false,//设置为true会出现"服务器不支持安全连接的错误"
DeliveryMethod = SmtpDeliveryMethod.Network,
})
{
#region Send Message
var mail = new MailMessage
{
From = new MailAddress(MessageManager.Instance.Address, MessageManager.Instance.DisplayName),
Subject = subject,
Body = body,
IsBodyHtml = true,
};
MailAddressCollection mailAddressCollection = new MailAddressCollection();
recipients.ToList().ForEach(i =>
{
mail.To.Add(i);
});
if (isAsync)
{
client.SendCompleted += new SendCompletedEventHandler(client_SendCompleted);
client.SendAsync(mail, recipients);
}
else
{
client.Send(mail);
}
#endregion
}
}
} void client_SendCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
{
string arr = null;
(e.UserState as List<string>).ToList().ForEach(i => { arr += i; });
//发送完成后要做的事件，可能是写日志
} #endregion
}
OK，有了消息的行业，我们再来看它的主体，即消息体，一般由发送者，接受者集合，主题，正文，是否立即发送等几个参数组成，下面来分享一下：补充一句，如果消息体的实现是单一的，我们可以把行为写在消息体里，形成一个消息上下文，微软很多架构都是这样做的，如EF数据上下文DbContext,ObjectContext,linq to sql上下文DataContext，Http上下文HttpContext等等。
/// <summary>
/// 消息实体
/// </summary>
public class MessageContext
{
/// <summary>
/// 消息类型
/// </summary>
public MessageType Type { get; set; }
/// <summary>
/// 消息头
/// </summary>
public string Subject { get; set; }
/// <summary>
/// 消息正文
/// </summary>
public string Body { get; set; }
/// <summary>
/// 接受方地址列表
/// </summary>
public IEnumerable<string> Addresses { get; set; }
/// <summary>
/// 是否处于准备发送状态
/// </summary>
public bool MessagePrepared { get; set; } public MessageContext()
{
Addresses = Enumerable.Empty<string>();
}
}
有了主体，再来看一下主要消息的设置，我们可以使用config中的section节点来做这事，如下：
/// <summary>
/// Message块，在web.config中提供Message块定义
/// </summary>
internal class MessageSection : ConfigurationSection
{
/// <summary>
/// 账号
/// </summary>
[ConfigurationProperty("UserName", DefaultValue = "bfyxzls")]
public string UserName
{
get { return (string)this["UserName"]; }
set { this["UserName"] = value; }
}
/// <summary>
/// 密码
/// </summary>
[ConfigurationProperty("Password", DefaultValue = "gemini123")]
public string Password
{
get { return (string)this["Password"]; }
set { this["Password"] = value; }
}
/// <summary>
/// 邮件服务器地址
/// </summary>
[ConfigurationProperty("Host", DefaultValue = "smtp.sina.com")]
public string Host
{
get { return (string)this["Host"]; }
set { this["Host"] = value; }
}
/// <summary>
/// 端口号
/// </summary>
[ConfigurationProperty("Port", DefaultValue = "")]
public int Port
{
get { return (int)this["Port"]; }
set { this["Port"] = value; }
}
/// <summary>
/// 发件人的email地址
/// </summary>
[ConfigurationProperty("Address", DefaultValue = "bfyxzls@sina.com")]
public string Address
{
get { return (string)this["Address"]; }
set { this["Address"] = value; }
}
/// <summary>
/// 发送之后，在收件人端显示的名称
/// </summary>
[ConfigurationProperty("DisplayName", DefaultValue = "占占")]
public string DisplayName
{
get { return (string)this["DisplayName"]; }
set { this["DisplayName"] = value; }
} }
config中的配置信息如下：
<configuration>
<configSections>
<section name="MessageSection" type="Messaging.MessageSection"/>
</configSections>
<MessageSection UserName="" Password="gemini123" Host="smtp.qq.com" Port="" Address="853066980@qq.com" DisplayName="大占"></MessageSection>
</configuration>
OK，我们再来看一下，消息的类型，目前可以定义两种消息，当然，为了组件的扩展性，你的类型可以通过IoC去代替它，这样可以避免程序中的硬编码，维护更方便
/// <summary>
/// 消息类型
/// </summary>
public enum MessageType
{
/// <summary>
/// 电子邮件
/// </summary>
Email,
/// <summary>
/// 短信息
/// </summary>
ShortMessage, }
最后来看一下生产消息的对象，使用了简单工厂模式，当然这只是个例子，实现中，它应该是使用IoC动态生产的，呵呵。
/// <summary>
/// 消息生产者
/// </summary>
public class MessageFactory
{
/// <summary>
/// 消息对象
/// </summary>
public static IMessageManager Instance
{
get
{
MessageType messageType = MessageType.Email;//通过配置产生
switch (messageType)
{
case MessageType.Email:
return new EmailMessageManager();
case MessageType.ShortMessage:
throw new NotImplementedException("没实现呢，呵呵");
default:
throw new ArgumentException("您输入的参数有误");
}
}
}
}