本文共 5214 字，大约阅读时间需要 17 分钟。

MediatR介绍

.NET中的简单中介者模式实现，一种进程内消息传递机制（无其他外部依赖）。 支持以同步或异步的形式进行请求/响应，命令，查询，通知和事件的消息传递，并通过C#泛型支持消息的智能调度。

MediatRMediatR.Extensions.Microsoft.DependencyInjection

第一种使用方式：CQRS

Handlers

public class MakeOrderCommandHandler : IRequestHandler
   
    {
       public Task
    
      Handle(MakeOrderRequestModel request, CancellationToken cancellationToken)    {
           var result = new MakeOrderResponseModel        {
               IsSuccess = true,            OrderId = new Guid("53d26807-ad70-4449-8479-024c54eb2020")        };        // 业务逻辑        return Task.FromResult(result);    }}
    
   

public class GetOrderByIdQueryHandler : IRequestHandler
   
    {
       public Task
    
      Handle(GetOrderByIdRequestModel request, CancellationToken cancellationToken)    {
           var orderDetails = new GetOrderByIdResponseModel();        // 业务逻辑        return Task.FromResult(orderDetails);    }}
    
   

RequestModels

public class MakeOrderRequestModel : IRequest
   
    {
       public Guid OrderId {
    get; set; }    public string OrderName {
    get; set; }    public DateTime DateOrder {
    get; set; }    public Guid ProductId {
    get; set; }    public int Quantity {
    get; set; }    public double Amount {
    get; set; }    public Guid OrderPersonId {
    get; set; }}
   

public class GetOrderByIdRequestModel : IRequest
   
    {
       public Guid OrderId {
    get; set; }}
   

ResponseModels

public class MakeOrderResponseModel{
       public bool IsSuccess {
    get; set; }    public Guid OrderId {
    get; set; }}

public class GetOrderByIdResponseModel{
       public Guid OrderId {
    get; set; }    public string OrderName {
    get; set; }    public DateTime DateOrder {
    get; set; }    public Guid ProductId {
    get; set; }    public int Quantity {
    get; set; }    public double Amount {
    get; set; }    public Guid OrderPersonId {
    get; set; }    public string ProductName {
    get; set; }    public string OrderPersonName {
    get; set; }}

注入

public class Startup{
       public Startup(IConfiguration configuration)    {
           Configuration = configuration;    }    public IConfiguration Configuration {
    get; }    // This method gets called by the runtime. Use this method to add services to the container.    public void ConfigureServices(IServiceCollection services)    {
           services.AddControllers();        services.AddMediatR(Assembly.GetExecutingAssembly());    }    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)    {
           if (env.IsDevelopment())        {
               app.UseDeveloperExceptionPage();        }        app.UseRouting();        app.UseAuthorization();        app.UseEndpoints(endpoints =>        {
               endpoints.MapControllers();        });    }}

使用

[Route("api/[controller]")][ApiController]public class OrderController : ControllerBase{
       private readonly IMediator _mediator;    public OrderController(IMediator mediator)    {
           _mediator = mediator;    }    [HttpPost]    public IActionResult MakeOrder([FromBody] MakeOrderRequestModel requestModel)    {
           var response = _mediator.Send(requestModel).Result;        return Ok(response);    }    [HttpGet]    public IActionResult OrderDetails(Guid id)    {
           var response = _mediator.Send(new GetOrderByIdRequestModel {
   OrderId = id}).Result;        return Ok(response);    }}

第二种使用方式：发布订阅模式

Handlers

public class GeneralNotificationHandler : INotificationHandler
   
    {
       public Task Handle(GeneralNotificationModel notification, CancellationToken cancellationToken)    {
           Console.WriteLine($"{notification.Title}：{notification.Content}");        return Task.CompletedTask;    }}public class LogHandler : INotificationHandler
    
     {
       private readonly ILogger
     
       _logger;    public LogHandler(ILogger
      
        logger)    {
           _logger = logger;    }    public Task Handle(GeneralNotificationModel notification, CancellationToken cancellationToken)    {
           _logger.LogInformation($"{notification.Title}：{notification.Content}");        return Task.CompletedTask;    }}
      
     
    
   

NotificationModels

public class GeneralNotificationModel : INotification{
       public string Title {
    get; set; }    public string Content {
    get; set; }    public GeneralNotificationModel(string title, string content)    {
           Title = title;        Content = content;    }}

使用

public class MakeOrderCommandHandler : IRequestHandler
   
    {
       private readonly IMediator _mediator;    public MakeOrderCommandHandler(IMediator mediator)    {
           _mediator = mediator;    }    public Task
    
      Handle(MakeOrderRequestModel request, CancellationToken cancellationToken)    {
           var result = new MakeOrderResponseModel        {
               IsSuccess = true,            OrderId = new Guid("53d26807-ad70-4449-8479-024c54eb2020")        };        //发布        _mediator.Publish(new GeneralNotificationModel("已下单", result.OrderId.ToString()), cancellationToken);        return Task.FromResult(result);    }}
    
   

转载地址：https://codeboy.blog.csdn.net/article/details/108524529 如侵犯您的版权，请留言回复原文章的地址，我们会给您删除此文章，给您带来不便请您谅解！