如何:实现松耦合事件
代码示例
以下过程和示例说明了如何实现事件类和事件接收器(用于实现公共事件接口)以及如何实现用于触发事件的发布程序。有关使用 COM+ 松耦合事件模型的详细信息,请参阅松耦合事件。
实现松耦合事件
定义事件接口。例如,下面的代码定义了一个名为
IlceMsg
的事件接口,其中包含名为EventMethod
的方法。Public Interface ILceMsg Sub EventMethod(message As String) End Interface
public interface ILceMsg { void EventMethod(string message); }
定义从 System.EnterpriseServices.ServicedComponent 类派生的事件类并实现在步骤 1 中定义的事件接口。例如,下面的代码定义名为
LceClass
的事件类。<EventClass()> _ Public Class LceClass Inherits ServicedComponent Implements ILceMsg Public Sub EventMethod(message As String) implements _ ILceMsg.EventMethod End Sub End Class
[EventClass] public class LceClass : ServicedComponent, ILceMsg { public void EventMethod(string message){} }
定义从 System.EnterpriseServices.ServicedComponent 类派生的事件接收器类并实现在步骤 1 中定义的事件接口。例如,下面的代码定义名为
LceSink
的事件接收器类。<EventClass()> _ Public Class LceSink Inherits ServicedComponent Implements ILceMsg Public Sub EventMethod(message As String) implements _ ILceMsg.EventMethod MessageBox.Show(message, "Event sink") End Sub End Class
public class LceSink : ServicedComponent, ILceMsg { public void EventMethod(string message) { MessageBox.Show(message, "Event sink"); } }
创建用于触发 LCE 的事件发布程序。
Protected Sub Fire_Click(sender As Object, e As System.EventArgs)_ Handles fireEvent.Click Dim evt As ILceMsg = CType(New LceClass(), ILceMsg) evt.EventMethod("Hello events") End Sub
protected void Fire_Click (object sender, System.EventArgs e) { ILceMsg evt = (ILceMsg) new LceClass(); evt.EventMethod("Hello events"); }
示例
Imports System
Imports System.IO
Imports System.Reflection
Imports System.EnterpriseServices
Imports System.Runtime.InteropServices
<assembly: ApplicationName("EventDemo")>
<assembly: ApplicationActivation(ActivationOption.Library)>
<assembly: AssemblyKeyFile("EventDemoSvr.snk")>
Namespace EventDemo
Public Interface ILceMsg
Sub EventMethod(message As String)
End Interface
<EventClass()> _
Public Class LceClass
Inherits ServicedComponent Implements ILceMsg
Public Sub EventMethod(message As String) implements _
ILceMsg.EventMethod
End Sub
End Class
Public Class LceSink
Inherits ServicedComponent Implements ILceMsg
Public Sub EventMethod(message As String) implements _
ILceMsg.EventMethod
MessageBox.Show(message, "Event sink")
End Sub
End Class
End Namespace
using System;
using System.IO;
using System.Reflection;
using System.EnterpriseServices;
using System.Runtime.InteropServices;
[assembly: ApplicationName("EventDemo")]
[assembly: ApplicationActivation(ActivationOption.Library)]
[assembly: AssemblyKeyFile("EventDemoSvr.snk")]
namespace EventDemo
{
public interface ILceMsg
{
void EventMethod(string message);
}
[EventClass]
public class LceClass : ServicedComponent, ILceMsg
{
public void EventMethod(string message){}
}
public class LceSink : ServicedComponent, ILceMsg
{
public void EventMethod(string message)
{
MessageBox.Show(message, "Event sink");
}
}
}
Publisher
Protected Sub Fire_Click(sender As Object, e As System.EventArgs)_
Handles fireEvent.Click
Dim evt As ILceMsg = CType(New LceClass(), ILceMsg)
evt.EventMethod("Hello events")
End Sub
//Publisher
protected void Fire_Click (object sender, System.EventArgs e)
{
ILceMsg evt = (ILceMsg) new LceClass();
evt.EventMethod("Hello events");
}
请参见
参考
System.EnterpriseServices Namespace
概念
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