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/Services/MessageService.cs

@@ -1,4 +1,6 @@
 using AutoMapper;
+using IM_API.Application.Interfaces;
+using IM_API.Domain.Events;
 using IM_API.Dtos;
 using IM_API.Exceptions;
 using IM_API.Interface.Services;
@@ -13,11 +15,13 @@ namespace IM_API.Services
         private readonly ImContext _context;
         private readonly ILogger<MessageService> _logger;
         private readonly IMapper _mapper;
-        public MessageService(ImContext context, ILogger<MessageService> logger, IMapper mapper)
+        private readonly IEventBus _eventBus;
+        public MessageService(ImContext context, ILogger<MessageService> logger, IMapper mapper, IEventBus eventBus)
         {
             _context = context;
             _logger = logger;
             _mapper = mapper;
+            _eventBus = eventBus;
         }
 
         public async Task<List<MessageBaseDto>> GetMessagesAsync(int userId, int conversationId, int? msgId, int? pageSize, bool desc)
@@ -92,6 +96,7 @@ namespace IM_API.Services
             message.StreamKey = StreamKeyBuilder.Group(groupId);
             _context.Messages.Add(message);
             await _context.SaveChangesAsync();
+            await _eventBus.PublishAsync(_mapper.Map<MessageCreatedEvent>(message));
             return _mapper.Map<MessageBaseDto>(message);
 
         }
@@ -107,6 +112,7 @@ namespace IM_API.Services
             message.StreamKey = StreamKeyBuilder.Private(dto.SenderId, dto.ReceiverId);
             _context.Messages.Add(message);
             await _context.SaveChangesAsync();
+            await _eventBus.PublishAsync(_mapper.Map<MessageCreatedEvent>(message));
             return _mapper.Map<MessageBaseDto>(message);
         }
         #endregion