fix bug

lib/src/enum/listener_type.dart

@@ -0,0 +1,33 @@
+
+class ListenerType {
+  ///
+  ///
+  static const String simpleMsgListener = 'simpleMsgListener';
+
+  ///
+  ///
+  static const String initSDKListener = 'initSDKListener';
+
+  ///
+  ///
+  static const String groupListener = 'groupListener';
+
+  ///
+  ///
+  static const String advancedMsgListener = 'advancedMsgListener';
+
+  ///
+  ///
+  static const String conversationListener = 'conversationListener';
+
+  ///
+  ///
+  static const String friendListener = 'friendListener';
+
+  ///
+  ///
+  static const String signalingListener = 'signalingListener';
+
+  ///
+  static const String msgSendProgressListener = "msgSendProgressListener";
+}

lib/src/enum/message_type.dart

@@ -0,0 +1,18 @@
+class MessageType {
+  ///
+  static const text = 101;
+
+  ///
+  static const picture = 102;
+
+  ///
+  static const voice = 103;
+
+  ///
+  static const video = 104;
+
+  ///
+  static const file = 105;
+
+  static const accept_friend = 201;
+}