diff --git a/lib/manager/cmd_manager.dart b/lib/manager/cmd_manager.dart
index e8da876..0a269ad 100644
--- a/lib/manager/cmd_manager.dart
+++ b/lib/manager/cmd_manager.dart
@@ -1,5 +1,7 @@
 import 'dart:collection';
 
+import 'package:wukongimfluttersdk/db/const.dart';
+
 import '../entity/cmd.dart';
 
 class WKCMDManager {
@@ -9,7 +11,7 @@ class WKCMDManager {
 
   HashMap<String, Function(WKCMD)>? _cmdback;
   handleCMD(dynamic json) {
-    String cmd = json['cmd'];
+    String cmd = WKDBConst.readString(json, 'cmd');
     dynamic param = json['param'];
     WKCMD wkcmd = WKCMD();
     wkcmd.cmd = cmd;
diff --git a/lib/manager/connect_manager.dart b/lib/manager/connect_manager.dart
index 18c024b..984773d 100644
--- a/lib/manager/connect_manager.dart
+++ b/lib/manager/connect_manager.dart
@@ -4,6 +4,7 @@ import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
 import 'package:connectivity/connectivity.dart';
+import 'package:wukongimfluttersdk/db/const.dart';
 
 import 'package:wukongimfluttersdk/db/wk_db_helper.dart';
 import 'package:wukongimfluttersdk/entity/msg.dart';
@@ -395,7 +396,7 @@ class WKConnectionManager {
     msg.orderSeq = await WKIM.shared.messageManager
         .getMessageOrderSeq(msg.messageSeq, msg.channelID, msg.channelType);
     dynamic contentJson = jsonDecode(msg.content);
-    msg.contentType = contentJson['type'];
+    msg.contentType = WKDBConst.readInt(contentJson, 'type');
     msg.isDeleted = _isDeletedMsg(contentJson);
     msg.messageContent = WKIM.shared.messageManager
         .getMessageModel(msg.contentType, contentJson);
diff --git a/lib/manager/message_manager.dart b/lib/manager/message_manager.dart
index 6098fa0..dc993e5 100644
--- a/lib/manager/message_manager.dart
+++ b/lib/manager/message_manager.dart
@@ -3,6 +3,7 @@ import 'dart:convert';
 
 import 'package:uuid/uuid.dart';
 import 'package:wukongimfluttersdk/common/logs.dart';
+import 'package:wukongimfluttersdk/db/const.dart';
 import 'package:wukongimfluttersdk/db/message.dart';
 import 'package:wukongimfluttersdk/entity/msg.dart';
 import 'package:wukongimfluttersdk/model/wk_media_message_content.dart';
@@ -63,8 +64,8 @@ class WKMessageManager {
       wkMsg.contentType = WkMessageContentType.contentFormatError;
       return;
     }
-    if (wkMsg.fromUID == '') {
-      wkMsg.fromUID = json['from_uid'];
+    if (wkMsg.fromUID == "") {
+      wkMsg.fromUID = WKDBConst.readString(json, 'from_uid');
     }
     if (wkMsg.channelType == WKChannelType.personal &&
         wkMsg.channelID != '' &&