初步完成Mqtt后台服务的改造

DMS.Infrastructure/Services/MqttDeviceContext.cs

@@ -0,0 +1,48 @@
+using DMS.Core.Models;
+using DMS.Infrastructure.Interfaces.Services;
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+
+namespace DMS.Infrastructure.Services
+{
+    /// <summary>
+    /// MQTT设备上下文，用于存储单个MQTT服务器的连接信息和状态
+    /// </summary>
+    public class MqttDeviceContext
+    {
+        /// <summary>
+        /// MQTT服务器配置
+        /// </summary>
+        public MqttServer MqttServer { get; set; }
+
+        /// <summary>
+        /// MQTT服务实例
+        /// </summary>
+        public IMqttService MqttService { get; set; }
+
+        /// <summary>
+        /// 连接状态
+        /// </summary>
+        public bool IsConnected { get; set; }
+
+        /// <summary>
+        /// 重连尝试次数
+        /// </summary>
+        public int ReconnectAttempts { get; set; }
+
+        /// <summary>
+        /// 与该MQTT服务器关联的所有变量MQTT别名
+        /// </summary>
+        public ConcurrentDictionary<int, VariableMqttAlias> VariableMqttAliases { get; set; }
+
+        /// <summary>
+        /// 构造函数
+        /// </summary>
+        public MqttDeviceContext()
+        {
+            VariableMqttAliases = new ConcurrentDictionary<int, VariableMqttAlias>();
+            ReconnectAttempts = 0;
+        }
+    }
+}