diff --git a/Windows/CS/Framework4.0/Toprie/Toprie/DeviceManager.cs b/Windows/CS/Framework4.0/Toprie/Toprie/DeviceManager.cs
index 43da737..b703c38 100644
--- a/Windows/CS/Framework4.0/Toprie/Toprie/DeviceManager.cs
+++ b/Windows/CS/Framework4.0/Toprie/Toprie/DeviceManager.cs
@@ -165,7 +165,7 @@ namespace JoyD.Windows.CS.Toprie
         private List<DeviceInfo> _deviceList = new List<DeviceInfo>();
         
         // 目标设备ID，用于指定ID连接
-        private int _targetDeviceId = -1;
+        private readonly int _targetDeviceId = -1;
         // 当前设备ID
         private int _currentDeviceId = -1;
         // 默认设备IP