diff --git a/linesider_screen_tool/Hepler/BartenderPrintingTool.cs b/linesider_screen_tool/Hepler/BartenderPrintingTool.cs
index d1c2281..f8f6798 100644
--- a/linesider_screen_tool/Hepler/BartenderPrintingTool.cs
+++ b/linesider_screen_tool/Hepler/BartenderPrintingTool.cs
@@ -224,7 +224,7 @@ namespace linesider_screen_tool
 
                 bool allSuccess = true;
 
-                // 遍历所有标签数据并打印
+                // 遍历所有标签字典数据并打印
                 foreach (var subStringValues in batchSubStringValues)
                 {
                     try
diff --git a/linesider_screen_tool/Hepler/MQTTHepler.cs b/linesider_screen_tool/Hepler/MQTTHepler.cs
index ef4595a..9ee9593 100644
--- a/linesider_screen_tool/Hepler/MQTTHepler.cs
+++ b/linesider_screen_tool/Hepler/MQTTHepler.cs
@@ -26,8 +26,8 @@ namespace linesider_screen_tool
         /// <summary>
         /// 初始化 MQTT 客户端
         /// </summary>
-        public MQTTHepler(string server, int port = 1883, string clientId = null,
-                         string username = null, string password = null, bool cleanSession = true)
+        public MQTTHepler(string server, int port = 1883, string clientId = "demo_test001",
+                         string username = "admin", string password = "public123", bool cleanSession = true)
         {
             _server = server;
             _port = port;
diff --git a/linesider_screen_tool/Hepler/SerialPortHepler.cs b/linesider_screen_tool/Hepler/SerialPortHepler.cs
index bc22a7f..d3b2615 100644
--- a/linesider_screen_tool/Hepler/SerialPortHepler.cs
+++ b/linesider_screen_tool/Hepler/SerialPortHepler.cs
@@ -12,7 +12,7 @@ namespace linesider_screen_tool
 {
     public class SerialPortHepler:IDisposable
     {
-        private SerialPort _serialPort;
+        private SerialPort? _serialPort;
         // 内部缓冲区用于存储接收到的数据
         private StringBuilder receiveBuffer = new StringBuilder();
         public event Action<string> DataReceived;