初步添加报警功能

DMS.Core/Events/AlarmEventArgs.cs

@@ -0,0 +1,27 @@
+using System;
+
+namespace DMS.Core.Events
+{
+    public class AlarmEventArgs : EventArgs
+    {
+        public int VariableId { get; }
+        public string VariableName { get; }
+        public double CurrentValue { get; }
+        public double ThresholdValue { get; }
+        public string Message { get; }
+        public DateTime Timestamp { get; }
+        public string AlarmType { get; } // 可以是 "High", "Low", "Change" 等
+
+        public AlarmEventArgs(int variableId, string variableName, double currentValue, 
+                              double thresholdValue, string message, string alarmType)
+        {
+            VariableId = variableId;
+            VariableName = variableName;
+            CurrentValue = currentValue;
+            ThresholdValue = thresholdValue;
+            Message = message;
+            Timestamp = DateTime.Now;
+            AlarmType = alarmType;
+        }
+    }
+}