P2: DeviceHealthMonitor 重连增加指数退避策略（3→5→7→...→15）

UIShare/GlobalVariable/DeviceHealthMonitor.cs

@@ -34,8 +34,14 @@ namespace UIShare.GlobalVariable
         /// <summary>每个设备的连续失败计数</summary>
         private readonly ConcurrentDictionary<string, int> _failureCounts = new();
 
-        /// <summary>连续失败次数阈值，达到后触发重连</summary>
-        private const int FailureThreshold = 3;
+        /// <summary>每个设备的重连尝试次数（用于计算退避阈值）</summary>
+        private readonly ConcurrentDictionary<string, int> _reconnectAttempts = new();
+
+        /// <summary>基础失败阈值（首次重连触发值）</summary>
+        private const int BaseFailureThreshold = 3;
+
+        /// <summary>退避上限（最大阈值）</summary>
+        private const int MaxBackoffThreshold = 15;
 
         /// <summary>健康检查间隔（毫秒）</summary>
         private readonly int _checkIntervalMs;
@@ -73,7 +79,7 @@ namespace UIShare.GlobalVariable
                     null,
                     TimeSpan.FromSeconds(10),     // 首次检查延迟 10 秒，避免启动时设备尚未连接完成
                     TimeSpan.FromMilliseconds(_checkIntervalMs));
-                LoggerHelper.Info($"[{_scopeName}] 设备健康监控已启动，检查间隔={_checkIntervalMs}ms，重连阈值={FailureThreshold}次");
+                LoggerHelper.Info($"[{_scopeName}] 设备健康监控已启动，检查间隔={_checkIntervalMs}ms，基础重连阈值={BaseFailureThreshold}次（指数退避上限={MaxBackoffThreshold}）");
             }
         }
 
@@ -86,6 +92,7 @@ namespace UIShare.GlobalVariable
                 _healthCheckTimer?.Dispose();
                 _healthCheckTimer = null;
                 _failureCounts.Clear();
+                _reconnectAttempts.Clear();
             }
         }
 
@@ -119,18 +126,23 @@ namespace UIShare.GlobalVariable
 
                     if (alive)
                     {
-                        // 连接正常：清零失败计数
+                        // 连接正常：清零失败计数与退避
                         _failureCounts.TryRemove(deviceName, out _);
+                        _reconnectAttempts.TryRemove(deviceName, out _);
                         continue;
                     }
 
                     // 连接断开：累加失败计数
                     int failures = _failureCounts.AddOrUpdate(deviceName, 1, (_, count) => count + 1);
 
-                    if (failures < FailureThreshold)
+                    // 计算当前退避阈值：基础值 + 重连尝试次数 × 2，上限为 MaxBackoffThreshold
+                    int attempts = _reconnectAttempts.GetOrAdd(deviceName, 0);
+                    int currentThreshold = Math.Min(BaseFailureThreshold + attempts * 2, MaxBackoffThreshold);
+
+                    if (failures < currentThreshold)
                     {
                         LoggerHelper.Warn(
-                            $"[{_scopeName}] 设备 [{deviceName}] 连接断开，等待重连中 ({failures}/{FailureThreshold})");
+                            $"[{_scopeName}] 设备 [{deviceName}] 连接断开，等待重连中 ({failures}/{currentThreshold})");
                         continue;
                     }
 
@@ -175,7 +187,9 @@ namespace UIShare.GlobalVariable
         {
             try
             {
-                LoggerHelper.Info($"[{_scopeName}] 设备 [{deviceName}] 连续 {FailureThreshold} 次检测断连，开始重连...");
+                int attempts = _reconnectAttempts.AddOrUpdate(deviceName, 1, (_, c) => c + 1);
+                int nextThreshold = Math.Min(BaseFailureThreshold + attempts * 2, MaxBackoffThreshold);
+                LoggerHelper.Info($"[{_scopeName}] 设备 [{deviceName}] 连续失败触发重连（第 {attempts} 次重连，下次阈值={nextThreshold}）...");
 
                 using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
                 bool ok = await device.ConnectAsync(cts.Token);
@@ -186,6 +200,7 @@ namespace UIShare.GlobalVariable
                 if (ok)
                 {
                     _failureCounts.TryRemove(deviceName, out _);
+                    _reconnectAttempts.TryRemove(deviceName, out _);
                     LoggerHelper.Info($"[{_scopeName}] 设备 [{deviceName}] 重连成功");
                 }
                 else