diff --git a/scripts/behaviorTree/BehaviorNode.cs b/scripts/behaviorTree/BehaviorNode.cs
index 03b09a7..f2f8c58 100644
--- a/scripts/behaviorTree/BehaviorNode.cs
+++ b/scripts/behaviorTree/BehaviorNode.cs
@@ -15,11 +15,6 @@ public partial class BehaviorNode : Node2D
         InvokeBehaviorTreeNode(true, delta);
     }
 
-    // public override void _Process(double delta)
-    // {
-    //     InvokeBehaviorTreeNode(false, delta);
-    // }
-
     /// <summary>
     /// <para>InvokeBehaviorTreeNode</para>
     /// <para>调用行为树节点</para>
diff --git a/scripts/behaviorTree/IBehaviorTree.cs b/scripts/behaviorTree/IBehaviorTree.cs
index e25a945..074fcb6 100644
--- a/scripts/behaviorTree/IBehaviorTree.cs
+++ b/scripts/behaviorTree/IBehaviorTree.cs
@@ -1,5 +1,9 @@
 namespace ColdMint.scripts.behaviorTree;
 
+/// <summary>
+/// <para>IBehavior Tree</para>
+/// <para>行为树</para>
+/// </summary>
 public interface IBehaviorTree
 {
     string? Id { get; }
diff --git a/scripts/behaviorTree/ai/AiAttackNode.cs b/scripts/behaviorTree/ai/AiAttackNode.cs
index aa145b7..c95111b 100644
--- a/scripts/behaviorTree/ai/AiAttackNode.cs
+++ b/scripts/behaviorTree/ai/AiAttackNode.cs
@@ -3,6 +3,10 @@ using ColdMint.scripts.character;
 
 namespace ColdMint.scripts.behaviorTree.ai;
 
+/// <summary>
+/// <para>AI attack node</para>
+/// <para>AI的攻击节点</para>
+/// </summary>
 public class AiAttackNode : BehaviorTreeNodeTemplate
 {
     public AiCharacter? Character { get; set; }
@@ -29,47 +33,49 @@ public class AiAttackNode : BehaviorTreeNodeTemplate
         var selfCamp = CampManager.GetCamp(Character.CampId);
         foreach (var node in nodesInTheAttackRange)
         {
-            if (node is CharacterTemplate characterTemplate)
+            if (node is not CharacterTemplate characterTemplate)
             {
-                if (node == Character)
-                {
-                    continue;
-                }
+                continue;
+            }
+            
+            if (node == Character)
+            {
+                continue;
+            }
 
-                var characterCamp = CampManager.GetCamp(characterTemplate.CampId);
-                var canCause = CampManager.CanCauseHarm(selfCamp, characterCamp);
-                if (!canCause)
-                {
-                    continue;
-                }
+            var characterCamp = CampManager.GetCamp(characterTemplate.CampId);
+            var canCause = CampManager.CanCauseHarm(selfCamp, characterCamp);
+            if (!canCause)
+            {
+                continue;
+            }
 
-                if (selfCamp == null || characterCamp == null)
-                {
-                    continue;
-                }
+            if (selfCamp == null || characterCamp == null)
+            {
+                continue;
+            }
+            
+            if (selfCamp.Id == characterCamp.Id)
+            {
+                //If it is the same side, do not attack, if allowed friend damage, this code will prevent the AI from actively attacking the player.
+                //如果是同一阵营，不攻击，如果允许友伤，这段代码会阻止AI主动攻击玩家。
+                continue;
+            }
 
-                if (selfCamp.Id == characterCamp.Id)
-                {
-                    //如果是同一阵营，不攻击
-                    continue;
-                }
-
-                var distance = characterTemplate.GlobalPosition - Character.GlobalPosition;
-                var distanceLength = distance.Length();
-                if (distanceLength < closestDistance)
-                {
-                    closestDistance = distanceLength;
-                    closestEnemy = characterTemplate;
-                }
+            var distance = characterTemplate.GlobalPosition.DistanceTo(Character.GlobalPosition);
+            if (distance < closestDistance)
+            {
+                closestDistance = distance;
+                closestEnemy = characterTemplate;
             }
         }
 
         if (closestEnemy != null && Character.AttackObstacleDetection != null)
         {
-            //There are the closest enemies
-            //有距离最近的敌人
-            var distance = closestEnemy.GlobalPosition - Character.GlobalPosition;
-            Character.AttackObstacleDetection.TargetPosition = distance;
+            //With the nearest enemy and no obstacles
+            //有距离最近的敌人，且没有障碍物
+            var distanceVector2 = closestEnemy.GlobalPosition - Character.GlobalPosition;
+            Character.AttackObstacleDetection.TargetPosition = distanceVector2;
             if (Character.AttackObstacleDetection.GetCollider() == null)
             {
                 Character.StopMoving();
diff --git a/scripts/behaviorTree/ai/AiPatrolNode.cs b/scripts/behaviorTree/ai/AiPatrolNode.cs
index cf0e9a5..586abdd 100644
--- a/scripts/behaviorTree/ai/AiPatrolNode.cs
+++ b/scripts/behaviorTree/ai/AiPatrolNode.cs
@@ -4,6 +4,7 @@ using ColdMint.scripts.character;
 namespace ColdMint.scripts.behaviorTree.ai;
 
 /// <summary>
+/// <para>AI patrol node</para>
 /// <para>AI巡逻节点</para>
 /// </summary>
 public class AiPatrolNode : SelectorNode
diff --git a/scripts/behaviorTree/framework/SequenceNode.cs b/scripts/behaviorTree/framework/SequenceNode.cs
index ba670cf..77904a8 100644
--- a/scripts/behaviorTree/framework/SequenceNode.cs
+++ b/scripts/behaviorTree/framework/SequenceNode.cs
@@ -14,7 +14,7 @@ public class SequenceNode : BehaviorTreeNodeTemplate
     /// <para>Check whether all child nodes are executed in sequence</para>
     /// <para>所有子节点是否按顺序执行完毕</para>
     /// </summary>
-    bool _complete = true;
+    private bool _complete = true;
 
     public override int Execute(bool isPhysicsProcess, double delta)
     {
diff --git a/scripts/camp/Camp.cs b/scripts/camp/Camp.cs
index 5e21b74..841e707 100644
--- a/scripts/camp/Camp.cs
+++ b/scripts/camp/Camp.cs
@@ -8,12 +8,11 @@ namespace ColdMint.scripts.camp;
 /// </summary>
 public class Camp
 {
-    private readonly string _id;
     private readonly List<string> _friendlyCampIdList;
 
     public Camp(string id)
     {
-        _id = id;
+        Id = id;
         _friendlyCampIdList = new List<string>();
     }
 
@@ -21,7 +20,7 @@ public class Camp
     /// <para>Get camp ID</para>
     /// <para>获取阵营ID</para>
     /// </summary>
-    public string Id => _id;
+    public string Id { get; }
 
     /// <summary>
     /// <para>Get camp name</para>
diff --git a/scripts/camp/CampManager.cs b/scripts/camp/CampManager.cs
index 37a1479..6014320 100644
--- a/scripts/camp/CampManager.cs
+++ b/scripts/camp/CampManager.cs
@@ -6,7 +6,7 @@ namespace ColdMint.scripts.camp;
 /// <para>Camp manager</para>
 /// <para>阵营管理器</para>
 /// </summary>
-public class CampManager
+public static class CampManager
 {
     private static readonly Dictionary<string, Camp?> Camps = new Dictionary<string, Camp?>();
 
diff --git a/scripts/character/AiCharacter.cs b/scripts/character/AiCharacter.cs
index 6c0765a..d40e5be 100644
--- a/scripts/character/AiCharacter.cs
+++ b/scripts/character/AiCharacter.cs
@@ -9,7 +9,7 @@ namespace ColdMint.scripts.character;
 /// <para>The role played by computers</para>
 /// <para>由电脑扮演的角色</para>
 /// </summary>
-public partial class AiCharacter : CharacterTemplate
+public sealed partial class AiCharacter : CharacterTemplate
 {
     /// <summary>
     /// <para>How fast the character moves</para>
@@ -67,10 +67,11 @@ public partial class AiCharacter : CharacterTemplate
 
         if (_attackArea != null)
         {
+            //If true, the zone will detect objects or areas entering and leaving the zone.
             //如果为true，该区域将检测进出该区域的物体或区域。
             _attackArea.Monitoring = true;
-            //Other regions cannot detect our pick region
-            //其他区域不能检测到我们的拾取区域
+            //Other areas can't detect our attack zone
+            //其他区域不能检测到我们的攻击区域
             _attackArea.Monitorable = false;
             _attackArea.BodyEntered += EnterTheAttackArea;
             _attackArea.BodyExited += ExitTheAttackArea;
@@ -83,12 +84,12 @@ public partial class AiCharacter : CharacterTemplate
         // _behaviorNode.Root = patrolBehaviorTree.Root;
     }
 
-    protected virtual void EnterTheAttackArea(Node node)
+    private void EnterTheAttackArea(Node node)
     {
         _nodesInTheAttackRange?.Add(node);
     }
 
-    protected virtual void ExitTheAttackArea(Node node)
+    private void ExitTheAttackArea(Node node)
     {
         _nodesInTheAttackRange?.Remove(node);
     }
diff --git a/scripts/character/CharacterTemplate.cs b/scripts/character/CharacterTemplate.cs
index a9910a7..019b65a 100644
--- a/scripts/character/CharacterTemplate.cs
+++ b/scripts/character/CharacterTemplate.cs
@@ -6,7 +6,6 @@ using ColdMint.scripts.damage;
 using ColdMint.scripts.debug;
 using ColdMint.scripts.health;
 using ColdMint.scripts.inventory;
-using ColdMint.scripts.map.events;
 using ColdMint.scripts.utils;
 using ColdMint.scripts.weapon;
 using Godot;
@@ -259,16 +258,18 @@ public partial class CharacterTemplate : CharacterBody2D
     /// </returns>
     public bool PickItem(Node2D? pickAbleItem)
     {
-        if (pickAbleItem == null)
+        //Empty reference checking is implicitly performed here.
+        //此处隐式的执行了空引用检查。
+        if (pickAbleItem is not IItem item)
         {
             return false;
         }
-
+        
         if (_itemContainer == null)
         {
             return false;
         }
-
+        
         //Get the currently selected node
         //拿到当前选择的节点
         var itemSlotNode = _itemContainer.GetSelectItemSlotNode();
@@ -277,11 +278,6 @@ public partial class CharacterTemplate : CharacterBody2D
             return false;
         }
 
-        if (pickAbleItem is not IItem item)
-        {
-            return false;
-        }
-
         //First check if we can pick up the item.
         //先检查我们能否拾起此物品。
         var canPick = _itemContainer.CanAddItem(item);
@@ -368,7 +364,7 @@ public partial class CharacterTemplate : CharacterBody2D
     /// <para>Update the role's health bar</para>
     /// <para>更新角色的健康条</para>
     /// </summary>
-    private void UpDataHealthBar(DamageTemplate damageTemplate)
+    private void UpDataHealthBar()
     {
         if (_healthBar == null)
         {
@@ -441,7 +437,7 @@ public partial class CharacterTemplate : CharacterBody2D
             return true;
         }
 
-        UpDataHealthBar(damageTemplate);
+        UpDataHealthBar();
         return true;
     }
 
diff --git a/scripts/inventory/HotBar.cs b/scripts/inventory/HotBar.cs
index af07b7f..6dff720 100644
--- a/scripts/inventory/HotBar.cs
+++ b/scripts/inventory/HotBar.cs
@@ -79,7 +79,7 @@ public partial class HotBar : HBoxContainer, IItemContainer
         {
             _selectIndex = count - 1;
         }
-        
+
         SelectItemSlot(oldSelectIndex, _selectIndex);
     }
 
@@ -223,6 +223,11 @@ public partial class HotBar : HBoxContainer, IItemContainer
     /// </summary>
     private void SelectItemSlot(int oldSelectIndex, int newSelectIndex)
     {
+        if (oldSelectIndex == newSelectIndex)
+        {
+            return;
+        }
+
         if (_itemSlotNodes == null)
         {
             return;
@@ -286,10 +291,7 @@ public partial class HotBar : HBoxContainer, IItemContainer
         {
             return false;
         }
-        else
-        {
-            return itemSlotNode.SetItem(item);
-        }
+        return itemSlotNode.SetItem(item);
     }
 
     public ItemSlotNode? GetSelectItemSlotNode()