1. CodeWF.EventBus
EventBus(事件总线),用于解耦模块之间的通讯。本库( CodeWF.EventBus [1] )适用于进程内消息传递(无其他外部依赖),与大家普遍使用的MediatR部分类似,但MediatR库侧重于 ASP.NET Core [2] 设计使用,而本库也有点点优势:
设计可在各种模板项目使用,如WPF、Winform、AvaloniaUI、ASP.NET Core等,主要参考了 Prism.Events [3] 设计;
参考 MASA Framework [4] 增强消息处理能力:
internal classMessageHandler
{
[EventHandler(Order = 3)]
privatevoidReceiveAutoCreateProductMessage3(CreateProductMessage message)
{
AddLog($"收到自动订阅消息3({message}」");
}
[EventHandler(Order = 1)]
privatevoidReceiveAutoDeleteProductMessage(DeleteProductMessage message)
{
AddLog($"收到自动订阅消息({message}」");
}
[EventHandler(Order = 2)]
privatevoidReceiveAutoCreateProductMessage2(CreateProductMessage message)
{
AddLog($"收到自动订阅消息2({message}」");
}
}
2. 怎么使用事件总线?
首先定义消息类,消息需要继承自
CodeWF.EventBus.Message
:
public classCreateProductMessage : CodeWF.EventBus.Message
{
publicstring Name { get; }
publicCreateProductMessage(object sender, string name) : base(sender)
{
Name = name;
}
publicoverridestringToString()
{
return$"创建产品消息-】产品名称:{Name}";
}
}
public classDeleteProductMessage : CodeWF.EventBus.Message
{
publicstring Id { get; }
publicDeleteProductMessage(object sender, string id) : base(sender)
{
Id = id;
}
publicoverridestringToString()
{
return$"删除产品消息-】产品Id:{Id}";
}
}
定义好消息,这里我们有两种方式使用事件总线,非IOC和IOC方式:
非IOC方式:需要安装
CodeWF.EventBus
包,适用于未使用IOC的模板程序,比如WPF、Winform、AvaloniaUI、控制台程序,当然ASP.NET Core也能用。IOC方式:需要安装
CodeWF.AspNetCore.EventBus
包,适合于在ASP.NET Core程序中使用。
2.1. 非IOC方式使用
适合于未使用IOC方式使用事件总线,比如在WPF、Winform、AvaloniaUI、控制台等程序中直接使用事件帮助类的静态实例,下面是使用步骤。
创建项目(不限于项目类型,比如控制台程序),通过NuGet引入
CodeWF.EventBus
包:
Install-Package CodeWF.EventBus -Version 1.0.1
创建消息处理程序,这里参考了Prism.Events设计,可订阅消息、取消订阅消息、发布消息,适合于手工指定处理方法:
internal classMessageHandler
{
internalvoidManuSubscribe()
{
Messenger.Default.Subscribe<CreateProductMessage>(this, ReceiveManuCreateProductMessage);
Messenger.Default.Subscribe<DeleteProductMessage>(this, ReceiveManuDeleteProductMessage);
}
internalvoidManuUnsubscribe()
{
Messenger.Default.Unsubscribe<CreateProductMessage>(this, ReceiveManuCreateProductMessage);
Messenger.Default.Unsubscribe<DeleteProductMessage>(this, ReceiveManuDeleteProductMessage);
}
internalvoidPublish()
{
Messenger.Default.Publish(this, new CreateProductMessage(this, $"{DateTime.Now:HHmmss}号产品"));
Messenger.Default.Publish(this, new DeleteProductMessage(this, $"{DateTime.Now:HHmmss}号"));
}
voidReceiveManuCreateProductMessage(CreateProductMessage message)
{
AddLog($"收到手动注册的{message}");
}
voidReceiveManuDeleteProductMessage(DeleteProductMessage message)
{
AddLog($"收到手动注册的{message}");
}
privatevoidAddLog(string message)
{
Console.WriteLine($"{DateTime.Now:HH:mm:ss fff}{message}\r\n");
}
}
最后是消息使用:
using ConsoleDemo.EventBus;
var handler = new MessageHandler();
Console.WriteLine("1、未注册时发布消息:");
handler.Publish();
Console.WriteLine();
Console.WriteLine("2、手动注册后发布消息:");
handler.ManuSubscribe();
handler.Publish();
Console.WriteLine("3、取消手动注册后发布消息:");
handler.ManuUnsubscribe();
handler.Publish();
Console.ReadKey();
如果消息较多,也可使用自动注册消息处理方法,我们修改处理程序:
internal classMessageHandler
{
internalvoidAutoSubscribe()
{
Messenger.Default.Subscribe(this);
}
internalvoidAutoUnsubscribe()
{
Messenger.Default.Unsubscribe(this);
}
internalvoidPublish()
{
Messenger.Default.Publish(this, new CreateProductMessage(this, $"{DateTime.Now:HHmmss}号产品"));
Messenger.Default.Publish(this, new DeleteProductMessage(this, $"{DateTime.Now:HHmmss}号"));
}
[EventHandler(Order = 3)]
privatevoidReceiveAutoCreateProductMessage3(CreateProductMessage message)
{
AddLog($"收到自动订阅消息3({message}」");
}
[EventHandler(Order = 1)]
privatevoidReceiveAutoDeleteProductMessage(DeleteProductMessage message)
{
AddLog($"收到自动订阅消息({message}」");
}
[EventHandler(Order = 2)]
privatevoidReceiveAutoCreateProductMessage2(CreateProductMessage message)
{
AddLog($"收到自动订阅消息2({message}」");
}
privatevoidAddLog(string message)
{
Console.WriteLine($"{DateTime.Now:HH:mm:ss fff}{message}\r\n");
}
}
[EventHandler(Order = 0)]
定义消息的执行顺序。每个消息都可以匹配多个处理程序。一个类中可以有多个消息处理方法,可以订阅同一个消息,也可以订阅不同的消息。
支持消息处理程序的注销:
注销指定处理程序:
Messenger.Default.Unsubscribe<CreateProductMessage>(this, ReceiveManuCreateProductMessage)
注销指定类的所有处理程序:
Messenger.Default.Unsubscribe(this)
消息使用:
using ConsoleDemo.EventBus;
var handler = new MessageHandler();
Console.WriteLine("1、未注册时发布消息:");
handler.Publish();
Console.WriteLine();
Console.WriteLine("2、自动注册后发布消息:");
handler.AutoSubscribe();
handler.Publish();
Console.WriteLine("3、取消自动注册后发布消息:");
handler.AutoUnsubscribe();
handler.Publish();
Console.ReadKey();
2.2. IOC方式使用
适合于在ASP.NET Core程序中使用,下面是使用步骤。
创建项目(ASP.NET Core模块项目,比如Web API、MVC、Razor Page、Blazor Server等),通过NuGet引入
CodeWF.AspNetCore.EventBus
:
Install-Package CodeWF.AspNetCore.EventBus -Version 1.0.1
创建消息处理程序,处理类中可以正常使用构造函数注入IOC服务:
public classMessageHandler
{
privatereadonly ITimeService timeService;
publicMessageHandler(ITimeService timeService)
{
this.timeService = timeService;
}
[EventHandler(Order = 3)]
publicvoidReceiveAutoCreateProductMessage3(CreateProductMessage message)
{
AddLog($"收到消息3({message}」");
}
[EventHandler(Order = 1)]
publicvoidReceiveAutoDeleteProductMessage(DeleteProductMessage message)
{
AddLog($"收到消息({message}」");
}
[EventHandler(Order = 2)]
publicvoidReceiveAutoCreateProductMessage2(CreateProductMessage message)
{
AddLog($"收到消息2({message}」");
}
privatevoidAddLog(string message)
{
Console.WriteLine($"{timeService.GetTime()}: {message}\r\n");
}
}
publicinterfaceITimeService
{
stringGetTime();
}
public classTimeService : ITimeService
{
publicstringGetTime()
{
return DateTime.Now.ToString("HH:mm:ss fff");
}
}
在Program中注册事件总线:
using CodeWF.AspNetCore.EventBus;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
// 用于测试事件处理类正常使用IOC功能
builder.Services.AddSingleton<ITimeService, TimeService>();
// 1、注册事件总线,将标注`EventHandler`特性方法的类采用单例方式注入IOC容器
builder.Services.AddEventBus();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
app.UseSwagger();
app.UseSwaggerUI();
}
app.UseAuthorization();
app.MapControllers();
// 2、将上面已经注入IOC容器的类取出、关联处理方法到事件总线管理
app.UseEventBus();
app.Run();
在控制器或其他服务可以发布消息,上面的处理程序会接收处理:
[ApiController]
[Route("[controller]")]
public classEventController : ControllerBase
{
privatereadonly ILogger<EventController> _logger;
privatereadonly IMessenger _messenger;
publicEventController(ILogger<EventController> logger, IMessenger messenger)
{
_logger = logger;
_messenger = messenger;
}
[HttpPost]
publicvoidAdd()
{
_messenger.Publish(this, new CreateProductMessage(this, $"{DateTime.Now:HHmmss}号产品"));
}
[HttpDelete]
publicvoidDelete()
{
_messenger.Publish(this, new DeleteProductMessage(this, $"{DateTime.Now:HHmmss}号"));
}
}
3. 总结
CodeWF.EventBus,一款灵活的事件总线库,实现模块间解耦通信。支持多种.NET项目类型,如WPF、WinForms、ASP.NET Core等。采用简洁设计,轻松实现事件的发布与订阅。通过有序的消息处理,确保事件得到妥善处理。简化您的代码,提升系统可维护性。立即体验CodeWF.EventBus,让事件处理更加高效!
仓库地址是https://github.com/dotnet9/CodeWF.EventBus,开发过程中参考不少开源项目,他们是:
Prism.Events
MediatR
MASA Framework
参考资料
[1]
CodeWF.EventBus:
https://www.nuget.org/packages?q=CodeWF.EventBus
ASP.NET Core:
https://learn.microsoft.com/zh-cn/aspnet/core/?view=aspnetcore-9.0
Prism.Events:
https://github.com/PrismLibrary/Prism/tree/master/src/Prism.Events
MASA Framework:
https://docs.masastack.com/framework/tutorial/mf-part-3#p-69828ff0