diff --git a/src/Notes-master/src/net/micode/notes/ui/DropdownMenu.java b/src/Notes-master/src/net/micode/notes/ui/DropdownMenu.java
index 613dc74..1631f43 100644
--- a/src/Notes-master/src/net/micode/notes/ui/DropdownMenu.java
+++ b/src/Notes-master/src/net/micode/notes/ui/DropdownMenu.java
@@ -28,34 +28,34 @@ import android.widget.PopupMenu.OnMenuItemClickListener;
 import net.micode.notes.R;
 
 public class DropdownMenu {
-    private Button mButton;
-    private PopupMenu mPopupMenu;
-    private Menu mMenu;
+    private Button mButton; // 下拉菜单的按钮
+    private PopupMenu mPopupMenu; // 弹出菜单
+    private Menu mMenu; // 菜单
 
     public DropdownMenu(Context context, Button button, int menuId) {
-        mButton = button;
-        mButton.setBackgroundResource(R.drawable.dropdown_icon);
-        mPopupMenu = new PopupMenu(context, mButton);
-        mMenu = mPopupMenu.getMenu();
-        mPopupMenu.getMenuInflater().inflate(menuId, mMenu);
+        mButton = button; // 设置按钮
+        mButton.setBackgroundResource(R.drawable.dropdown_icon); // 设置按钮的背景图为下拉图标
+        mPopupMenu = new PopupMenu(context, mButton); // 创建弹出菜单，关联到按钮
+        mMenu = mPopupMenu.getMenu(); // 获取菜单对象
+        mPopupMenu.getMenuInflater().inflate(menuId, mMenu); // 通过菜单资源ID填充菜单条目
         mButton.setOnClickListener(new OnClickListener() {
             public void onClick(View v) {
-                mPopupMenu.show();
+                mPopupMenu.show(); // 点击按钮时显示弹出菜单
             }
         });
     }
 
     public void setOnDropdownMenuItemClickListener(OnMenuItemClickListener listener) {
         if (mPopupMenu != null) {
-            mPopupMenu.setOnMenuItemClickListener(listener);
+            mPopupMenu.setOnMenuItemClickListener(listener); // 设置菜单条目点击监听器
         }
     }
 
     public MenuItem findItem(int id) {
-        return mMenu.findItem(id);
+        return mMenu.findItem(id); // 根据菜单条目ID查找菜单条目对象
     }
 
     public void setTitle(CharSequence title) {
-        mButton.setText(title);
+        mButton.setText(title); // 设置按钮的文本
     }
-}
+}
\ No newline at end of file