add(conversationSerivice):后端新增消息会话服务add(main)：完善主面板

backend/IM_API/Services/MessageService.cs

@@ -54,12 +54,24 @@ namespace IM_API.Services
         {
             throw new NotImplementedException();
         }
-
-        public Task<bool> SendGroupMessageAsync(int senderId, int groupId, MessageBaseDto dto)
+        #region 发送群消息
+        public async Task<bool> SendGroupMessageAsync(int senderId, int groupId, MessageBaseDto dto)
         {
-            throw new NotImplementedException();
-        }
+            //判断群存在
+            var isExist = await _context.Groups.AnyAsync(x => x.Id == groupId);
+            if (!isExist) throw new BaseException(CodeDefine.GROUP_NOT_FOUND);
+            //判断是否是群成员
+            var isMember = await _context.GroupMembers.AnyAsync(x => x.GroupId == groupId && x.UserId == senderId);
+            if (!isMember) throw new BaseException(CodeDefine.NO_GROUP_PERMISSION);
+            var message = _mapper.Map<Message>(dto);
+            message.Sender = senderId;
+            _context.Messages.Add(message);
+            await _context.SaveChangesAsync();
+            return true;
 
+        }
+        #endregion
+        #region 发送私聊消息
         public async Task<bool> SendPrivateMessageAsync(int senderId, int receiverId, MessageBaseDto dto)
         {
             bool isExist = await _context.Friends.AnyAsync(x => x.FriendId == receiverId);
@@ -70,5 +82,6 @@ namespace IM_API.Services
             await _context.SaveChangesAsync();
             return true;
         }
+        #endregion
     }
 }