diff --git a/lib/socket/socket_client.dart b/lib/socket/socket_client.dart
index 46fb253..f7d4692 100644
--- a/lib/socket/socket_client.dart
+++ b/lib/socket/socket_client.dart
@@ -97,7 +97,7 @@ class SocketClient {
             _byteList.getRange(0, _total).toList(growable: false));
         final message = utf8.decode(list);
         //print(message);
-        if (eventReceiveMessage != null) eventReceiveMessage(message);
+        eventReceiveMessage(message);
         _byteList = _byteList.getRange(_total, _byteList.length).toList();
         _total = -1;
         _parsing();
diff --git a/lib/utils/string_util.dart b/lib/utils/string_util.dart
index 24db6e5..4364554 100644
--- a/lib/utils/string_util.dart
+++ b/lib/utils/string_util.dart
@@ -22,12 +22,12 @@ String jsonPrettyEncode(Object? object) {
   return JsonEncoder.withIndent('  ').convert(object);
 }
 
-String incrementVersion(String version, {int fixedLength = 3}) {
+String incrementVersion(String version, {int fixedLength = 3, bool reverse = false}) {
   var parts = version.split('.').map(int.parse).toList();
   if (parts.length < fixedLength) {
     var needLength = fixedLength - parts.length;
     for (int i = 0; i < needLength; ++i) {
-      parts.add(0);
+      if(reverse) { parts.add(0); } else { parts.insert(0, 0); }
     }
   }