前端：

增加会话缓存
后端：
增加触发消息创建事件
增加消息创建事件触发后的处理函数

backend/IM_API/Hubs/ChatHub.cs

@@ -1,4 +1,7 @@
-using IM_API.Dtos;
+using AutoMapper;
+using IM_API.Application.Interfaces;
+using IM_API.Domain.Events;
+using IM_API.Dtos;
 using IM_API.Interface.Services;
 using IM_API.Models;
 using IM_API.Tools;
@@ -11,10 +14,14 @@ namespace IM_API.Hubs
     {
         private IMessageSevice _messageService;
         private readonly IConversationService _conversationService;
-        public ChatHub(IMessageSevice messageService, IConversationService conversationService)
+        private readonly IEventBus _eventBus;
+        private readonly IMapper _mapper;
+        public ChatHub(IMessageSevice messageService, IConversationService conversationService, IEventBus eventBus, IMapper mapper)
         {
             _messageService = messageService;
             _conversationService = conversationService;
+            _eventBus = eventBus;
+            _mapper = mapper;
         }
 
         public async override Task OnConnectedAsync()
@@ -51,8 +58,6 @@ namespace IM_API.Hubs
             {
                 msgInfo = await _messageService.SendGroupMessageAsync(int.Parse(userIdStr), dto.ReceiverId, dto);
             }
-
-                await Clients.Users(dto.ReceiverId.ToString()).SendAsync("ReceiveMessage", msgInfo);
             return;
         }
     }