遍历的数据不为空的时候

PLCDataReader/Main.cs

@@ -340,12 +340,13 @@ namespace UAS_PLCDataReader
         /// <param name="e"></param>
         private void TimerUpdateDevice_Tick(object sender, EventArgs e)
         {
-            foreach (var device in ReturnData)
-            {
-                Entity.Device item = device.Value;
-                LogicHandler.DoDevicePollingLog(item.Decode, item.SendDataSize.ToString(), item.ReceiveDataSize.ToString());
-                LogicHandler.UpdateDeviceData(item.Decode, item.ItemData);
-            }
+            if (ReturnData != null)
+                foreach (var device in ReturnData)
+                {
+                    Entity.Device item = device.Value;
+                    LogicHandler.DoDevicePollingLog(item.Decode, item.SendDataSize.ToString(), item.ReceiveDataSize.ToString());
+                    LogicHandler.UpdateDeviceData(item.Decode, item.ItemData);
+                }
             //while (QueueUpdateDevice.Count > 0)
             //{
             //    Entity.Device item = QueueUpdateDevice.Dequeue();