lib/app.dart

@@ -144,7 +144,7 @@ class _MyAppState extends State<MyApp> with WidgetsBindingObserver, BaseWidget {
         break;
       case AppLifecycleState.paused:
         // AppLog.log('App--->进入后台');
-        BlueManage().disconnect();
+        BlueManage.instance.disconnect();
         break;
       case AppLifecycleState.resumed:
         // AppLog.log('App--->进入前台');

lib/blue/blue_manage.dart

@@ -85,6 +85,12 @@ class BlueManage {
     return _manager;
   }
 
+  // 提供全局单例访问入口
+  static BlueManage get instance {
+    _manager ??= BlueManage._init();
+    return _manager!;
+  }
+
   BlueManage? get manager => shareManager();
 
   void _initBlue() {
@@ -94,9 +100,13 @@ class BlueManage {
   }
 
   void _initGetMtuSubscription() {
-    _mtuSubscription ??= bluetoothConnectDevice!.mtu.listen((int value) {
+    // 先取消之前的订阅，避免重复监听
+    _mtuSubscription?.cancel();
+    _mtuSubscription = null;
+    
+    _mtuSubscription = bluetoothConnectDevice!.mtu.listen((int value) {
       _mtuSize = value - 3;
-      AppLog.log('_mtuSizeValue:$value mtuSize:$_mtuSize');
+      AppLog.log('设备MTU变化 - 原始值:$value 计算后MTU:$_mtuSize 设备:${bluetoothConnectDevice?.remoteId.str}');
     });
   }
 
@@ -954,6 +964,12 @@ class BlueManage {
   Future<void> disconnect() async {
     try {
       connectDeviceMacAddress = '';
+      
+      // 清理MTU监听
+      _mtuSubscription?.cancel();
+      _mtuSubscription = null;
+      _mtuSize = 20; // 重置MTU为默认值
+      
       if (bluetoothConnectionState == BluetoothConnectionState.connected) {
         //加快蓝牙断连
         await bluetoothConnectDevice!.disconnect(timeout: 3);
@@ -975,10 +991,29 @@ class BlueManage {
     }
   }
 
+  // 获取当前MTU信息，用于调试
+  String getMtuDebugInfo() {
+    return 'MTU Debug Info:\n'
+        '- Current MTU Size: $_mtuSize\n'
+        '- Connected Device: ${bluetoothConnectDevice?.remoteId.str ?? "None"}\n'
+        '- Device Name: $connectDeviceName\n'
+        '- Connection State: $bluetoothConnectionState\n'
+        '- MTU Subscription Active: ${_mtuSubscription != null}';
+  }
+
   void disposed() {
     _sendStreamSubscription?.cancel();
-    _mtuSubscription!.cancel();
-    _adapterStateStateSubscription!.cancel();
-    _connectionStateSubscription!.cancel();
+    _mtuSubscription?.cancel();
+    _adapterStateStateSubscription?.cancel();
+    _connectionStateSubscription?.cancel();
+    
+    // 重置状态
+    _mtuSize = 20;
+    connectDeviceName = '';
+    connectDeviceMacAddress = '';
+    bluetoothConnectDevice = null;
+    scanDevices.clear();
+    allData.clear();
+    lastTimeData.clear();
   }
 }