加入 连接状态判断 控制台日志输出

lib/base/mqtt/mqtt.dart

@@ -8,6 +8,7 @@ import 'package:typed_data/src/typed_buffer.dart';
 class Mqtt {
   final MqttConfig _config;
   MqttClient? _client;
+  bool _connected = false;
   //标记是否自动重连
   bool reconnect = true;
   //缓存自定义主题订阅信息
@@ -26,10 +27,12 @@ class Mqtt {
     // _client?.autoReconnect = true;
     _client?.onConnected = () {
       // print("aa:mqtt服务器连接成功");
+      _connected = true;
       print("mqtt服务器: ${_config.host} 连接成功");
     };
     _client?.onDisconnected = () {
       // print("aa:mqtt服务器连接断开");
+      _connected = false;
       print("mqtt服务器: ${_config.host} 连接断开");
       //执行重连操作
       if (reconnect) {
@@ -48,6 +51,10 @@ class Mqtt {
     _mqtt = server;
   }
 
+  bool isConnected() {
+    return this._connected;
+  }
+
   Future<bool> connect({bool reconnect = false}) async {
     if (reconnect) {
       //限制重连速率