优化GUI程序，加入线程池，避免翻页卡死现象发生。

data_management/app.py

@@ -515,6 +515,10 @@ class DataManagementApp:
         """窗口关闭事件"""
         result = messagebox.askyesno("确认", "确定要退出系统吗？")
         if result:
+            # 清理图片加载器资源
+            from utils.image_loader import cleanup_resources
+            cleanup_resources()
+            
             # 关闭数据库连接
             self.mysql_manager.close()
             self.root.destroy()

data_management/ui/preview_panel.py

@@ -1,5 +1,10 @@
 """
-中间图片预览面板
+中间图片预览面板 - 优化版本
+主要优化:
+1. SQLite查询移到后台线程
+2. 使用线程池管理图片加载
+3. 添加取消机制,避免翻页时的线程冲突
+4. 正确清理图片对象,避免内存泄漏
 """
 import customtkinter as ctk
 from tkinter import messagebox
@@ -7,15 +12,17 @@ from typing import List, Dict, Callable, Optional
 import threading
 import sys
 import os
+from concurrent.futures import ThreadPoolExecutor, Future
+from collections import defaultdict
 
 # 添加父目录到路径
 sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 from config import GRID_COLUMNS, THUMBNAIL_SIZE, CARD_PADDING, ITEMS_PER_PAGE
-from utils.image_loader import load_image_from_url, create_placeholder_image
+from utils.image_loader import load_image_from_url, create_placeholder_image, get_thread_pool
 
 
 class ImageCard(ctk.CTkFrame):
-    """图片卡片组件"""
+    """图片卡片组件 - 优化版本"""
     
     def __init__(
         self,
@@ -36,6 +43,12 @@ class ImageCard(ctk.CTkFrame):
         # 勾选状态
         self.check_var = ctk.BooleanVar(value=False)
         
+        # 图片加载Future对象(用于取消)
+        self.load_future: Optional[Future] = None
+        
+        # 标记是否已销毁
+        self._destroyed = False
+        
         self._create_widgets()
         self._load_thumbnail()
     
@@ -61,7 +74,7 @@ class ImageCard(ctk.CTkFrame):
         self.image_label.pack(pady=5, padx=5)
         self.image_label.bind("<Button-1>", lambda e: self.on_preview(self.data))
         
-        # 物品名称（加粗）
+        # 物品名称(加粗)
         name_label = ctk.CTkLabel(
             self,
             text=self.data['goods_name'],
@@ -111,24 +124,42 @@ class ImageCard(ctk.CTkFrame):
         preview_btn.pack(pady=(0, 5), padx=5)
     
     def _load_thumbnail(self):
-        """异步加载缩略图"""
+        """使用线程池异步加载缩略图"""
         def load():
+            # 检查是否已销毁
+            if self._destroyed:
+                return
+            
             image = load_image_from_url(
                 self.data['image_url'],
                 size=(THUMBNAIL_SIZE, THUMBNAIL_SIZE)
             )
             
+            # 在主线程更新UI
+            if not self._destroyed:
+                self.after(0, lambda: self._set_image(image))
+        
+        # 使用全局线程池
+        thread_pool = get_thread_pool()
+        self.load_future = thread_pool.submit(load)
+    
+    def _set_image(self, image):
+        """设置图片(在主线程调用)"""
+        if self._destroyed:
+            return
+        
+        try:
             if image:
                 self.image_label.configure(image=image, text="")
-                self.image_label.image = image
+                self.image_label.image = image  # 保持引用
             else:
                 placeholder = create_placeholder_image(
                     size=(THUMBNAIL_SIZE, THUMBNAIL_SIZE)
                 )
                 self.image_label.configure(image=placeholder, text="")
                 self.image_label.image = placeholder
-        
-        threading.Thread(target=load, daemon=True).start()
+        except Exception as e:
+            print(f"设置图片失败: {e}")
     
     def _on_check(self):
         """勾选框改变"""
@@ -142,9 +173,23 @@ class ImageCard(ctk.CTkFrame):
         """设置勾选状态"""
         self.check_var.set(checked)
     
+    def cancel_loading(self):
+        """取消图片加载"""
+        if self.load_future and not self.load_future.done():
+            self.load_future.cancel()
+    
+    def cleanup(self):
+        """清理资源"""
+        self._destroyed = True
+        self.cancel_loading()
+        
+        # 清理图片引用
+        if hasattr(self.image_label, 'image'):
+            self.image_label.image = None
+
 
 class PreviewPanel(ctk.CTkFrame):
-    """中间图片预览面板"""
+    """中间图片预览面板 - 优化版本"""
     
     def __init__(
         self,
@@ -168,6 +213,12 @@ class PreviewPanel(ctk.CTkFrame):
         self.current_page = 1
         self.selected_ids = set()
         
+        # 下载状态缓存(避免重复查询SQLite)
+        self.download_status_cache = {}
+        
+        # 当前的ImageCard列表
+        self.image_cards: List[ImageCard] = []
+        
         self._create_widgets()
     
     def _create_widgets(self):
@@ -192,7 +243,7 @@ class PreviewPanel(ctk.CTkFrame):
         )
         self.count_label.pack(side="left", padx=20)
         
-        # 图片网格（可滚动）
+        # 图片网格(可滚动)
         self.scroll_frame = ctk.CTkScrollableFrame(self)
         self.scroll_frame.pack(fill="both", expand=True, padx=15, pady=(0, 10))
         
@@ -297,6 +348,46 @@ class PreviewPanel(ctk.CTkFrame):
         self.current_page = page
         self.selected_ids.clear()
         
+        # 在后台线程查询下载状态
+        def query_download_status():
+            try:
+                # 批量查询下载状态
+                status_dict = {}
+                for data in data_list:
+                    is_downloaded = self.sqlite_manager.is_downloaded(
+                        data['datasource'],
+                        data['image_url']
+                    )
+                    status_dict[data['id']] = is_downloaded
+                
+                # 在主线程更新UI
+                self.after(0, lambda: self._update_grid_with_status(status_dict))
+                
+            except Exception as e:
+                print(f"查询下载状态失败: {e}")
+                # 失败时使用空字典
+                self.after(0, lambda: self._update_grid_with_status({}))
+        
+        # 先显示加载中,然后在后台查询
+        self._show_loading()
+        threading.Thread(target=query_download_status, daemon=True).start()
+    
+    def _show_loading(self):
+        """显示加载中状态"""
+        # 清空现有卡片
+        self._clear_grid()
+        
+        loading_label = ctk.CTkLabel(
+            self.grid_frame,
+            text="加载中...",
+            font=("Arial", 14),
+            text_color="gray"
+        )
+        loading_label.grid(row=0, column=0, pady=50, padx=50)
+    
+    def _update_grid_with_status(self, status_dict: Dict[int, bool]):
+        """使用下载状态更新网格"""
+        self.download_status_cache = status_dict
         self._update_grid()
         self._update_stats()
         self._update_pagination()
@@ -304,8 +395,7 @@ class PreviewPanel(ctk.CTkFrame):
     def _update_grid(self):
         """更新图片网格"""
         # 清空现有卡片
-        for widget in self.grid_frame.winfo_children():
-            widget.destroy()
+        self._clear_grid()
         
         if not self.current_data:
             no_data_label = ctk.CTkLabel(
@@ -322,11 +412,8 @@ class PreviewPanel(ctk.CTkFrame):
             row = i // GRID_COLUMNS
             col = i % GRID_COLUMNS
             
-            # 检查是否已下载
-            is_downloaded = self.sqlite_manager.is_downloaded(
-                data['datasource'],
-                data['image_url']
-            )
+            # 从缓存获取下载状态
+            is_downloaded = self.download_status_cache.get(data['id'], False)
             
             card = ImageCard(
                 self.grid_frame,
@@ -343,10 +430,26 @@ class PreviewPanel(ctk.CTkFrame):
                 sticky="nsew"
             )
             
+            # 保存引用
+            self.image_cards.append(card)
+        
         # 配置网格列权重
         for col in range(GRID_COLUMNS):
             self.grid_frame.grid_columnconfigure(col, weight=1)
     
+    def _clear_grid(self):
+        """清空网格(正确清理资源)"""
+        # 先取消所有图片加载
+        for card in self.image_cards:
+            card.cleanup()
+        
+        # 清空列表
+        self.image_cards.clear()
+        
+        # 销毁所有子组件
+        for widget in self.grid_frame.winfo_children():
+            widget.destroy()
+    
     def _update_stats(self):
         """更新统计信息"""
         selected_count = len(self.selected_ids)
@@ -378,18 +481,16 @@ class PreviewPanel(ctk.CTkFrame):
     
     def _select_all(self):
         """全选"""
-        for widget in self.grid_frame.winfo_children():
-            if isinstance(widget, ImageCard):
-                widget.set_checked(True)
-                self.selected_ids.add(widget.data['id'])
+        for card in self.image_cards:
+            card.set_checked(True)
+            self.selected_ids.add(card.data['id'])
         
         self._update_stats()
     
     def _deselect_all(self):
         """取消全选"""
-        for widget in self.grid_frame.winfo_children():
-            if isinstance(widget, ImageCard):
-                widget.set_checked(False)
+        for card in self.image_cards:
+            card.set_checked(False)
         
         self.selected_ids.clear()
         self._update_stats()
@@ -422,15 +523,15 @@ class PreviewPanel(ctk.CTkFrame):
             if data['id'] in self.selected_ids
         ]
         
-        # 二次确认（简化版，不显示删除范围选项）
+        # 二次确认
         count = len(selected_data)
         confirm = messagebox.askyesno(
             "确认删除",
-            f"确定要删除选中的 {count} 张图片吗？\n\n"
+            f"确定要删除选中的 {count} 张图片吗?\n\n"
             "此操作将:\n"
             "1. 从MySQL数据库中删除记录\n"
-            "2. 删除已下载的本地文件（如有）\n\n"
-            "删除后无法恢复！",
+            "2. 删除已下载的本地文件(如有)\n\n"
+            "删除后无法恢复!",
             icon='warning'
         )
         
@@ -471,7 +572,7 @@ class PreviewPanel(ctk.CTkFrame):
                         print(f"删除记录失败 (ID: {data['id']}): {e}")
                         failed_ids.append(data['id'])
                 
-                # 更新UI（在主线程）
+                # 更新UI(在主线程)
                 self.after(0, lambda: self._on_delete_complete(success_count, len(failed_ids)))
                 
             except Exception as e:
@@ -494,7 +595,7 @@ class PreviewPanel(ctk.CTkFrame):
         # 清空选中
         self.selected_ids.clear()
         
-        # 调用删除回调，刷新数据
+        # 调用删除回调,刷新数据
         if self.on_delete_callback:
             self.on_delete_callback()
     
@@ -559,20 +660,20 @@ class PreviewPanel(ctk.CTkFrame):
     def _first_page(self):
         """首页"""
         if self.current_page > 1:
-            # 需要重新查询数据（在主应用中处理）
+            # 需要重新查询数据(在主应用中处理)
             pass
     
     def _prev_page(self):
         """上一页"""
         if self.current_page > 1:
-            # 需要重新查询数据（在主应用中处理）
+            # 需要重新查询数据(在主应用中处理)
             pass
     
     def _next_page(self):
         """下一页"""
         total_pages = (self.total_count + ITEMS_PER_PAGE - 1) // ITEMS_PER_PAGE
         if self.current_page < total_pages:
-            # 需要重新查询数据（在主应用中处理）
+            # 需要重新查询数据(在主应用中处理)
             pass
     
     def get_current_page(self) -> int:
@@ -585,6 +686,7 @@ class PreviewPanel(ctk.CTkFrame):
         self.total_count = 0
         self.current_page = 1
         self.selected_ids.clear()
-        self._update_grid()
+        self.download_status_cache.clear()
+        self._clear_grid()
         self._update_stats()
         self._update_pagination()

data_management/utils/image_loader.py

@@ -1,40 +1,92 @@
 """
 图片加载工具
 用于从URL加载图片并转换为PIL/CTkImage格式
+优化版本:使用连接池、线程池和缓存
 """
 import io
 import requests
 from PIL import Image
 from typing import Optional
 import customtkinter as ctk
+from concurrent.futures import ThreadPoolExecutor
+from functools import lru_cache
+import threading
 
 
+# ======================== 全局资源管理 ========================
+
+# HTTP会话(连接池)
+_session = None
+_session_lock = threading.Lock()
+
+def get_session() -> requests.Session:
+    """获取全局HTTP会话(单例模式)"""
+    global _session
+    if _session is None:
+        with _session_lock:
+            if _session is None:
+                _session = requests.Session()
+                # 配置连接池
+                adapter = requests.adapters.HTTPAdapter(
+                    pool_connections=10,  # 连接池大小
+                    pool_maxsize=20,      # 最大连接数
+                    max_retries=2,        # 重试次数
+                    pool_block=False
+                )
+                _session.mount('http://', adapter)
+                _session.mount('https://', adapter)
+    return _session
+
+
+# 线程池(用于图片加载)
+_thread_pool = None
+_thread_pool_lock = threading.Lock()
+
+def get_thread_pool() -> ThreadPoolExecutor:
+    """获取全局线程池(单例模式)"""
+    global _thread_pool
+    if _thread_pool is None:
+        with _thread_pool_lock:
+            if _thread_pool is None:
+                # 限制最多同时加载10张图片
+                _thread_pool = ThreadPoolExecutor(
+                    max_workers=10,
+                    thread_name_prefix="ImageLoader"
+                )
+    return _thread_pool
+
+
+# ======================== 图片加载函数 ========================
+
 def load_image_from_url(
     url: str,
     size: tuple = (150, 150),
-    timeout: int = 10
+    timeout: int = 5  # 降低超时时间,避免长时间阻塞
 ) -> Optional[ctk.CTkImage]:
     """
-    从URL加载图片
+    从URL加载图片(使用连接池)
     
     Args:
         url: 图片URL
         size: 目标尺寸 (width, height)
-        timeout: 超时时间（秒）
+        timeout: 超时时间(秒)
     
     Returns:
-        CTkImage对象，失败返回None
+        CTkImage对象,失败返回None
     """
     try:
+        # 使用全局session(连接复用)
+        session = get_session()
+        
         # 下载图片
-        response = requests.get(url, timeout=timeout)
+        response = session.get(url, timeout=timeout)
         response.raise_for_status()
         
         # 转换为PIL Image
         image_data = io.BytesIO(response.content)
         pil_image = Image.open(image_data)
         
-        # 转换为RGB（防止RGBA等格式问题）
+        # 转换为RGB(防止RGBA等格式问题)
         if pil_image.mode != 'RGB':
             pil_image = pil_image.convert('RGB')
         
@@ -47,17 +99,24 @@ def load_image_from_url(
         
         return ctk_image
         
+    except requests.exceptions.Timeout:
+        print(f"加载图片超时: {url}")
+        return None
+    except requests.exceptions.RequestException as e:
+        print(f"网络请求失败 {url}: {e}")
+        return None
     except Exception as e:
         print(f"加载图片失败 {url}: {e}")
         return None
 
 
+@lru_cache(maxsize=100)
 def create_placeholder_image(
     size: tuple = (150, 150),
     text: str = "加载失败"
 ) -> ctk.CTkImage:
     """
-    创建占位图片
+    创建占位图片(带缓存)
     
     Args:
         size: 图片尺寸
@@ -76,3 +135,18 @@ def create_placeholder_image(
     )
     
     return ctk_image
+
+
+def cleanup_resources():
+    """清理全局资源(程序退出时调用)"""
+    global _session, _thread_pool
+    
+    # 关闭线程池
+    if _thread_pool is not None:
+        _thread_pool.shutdown(wait=False)
+        _thread_pool = None
+    
+    # 关闭HTTP会话
+    if _session is not None:
+        _session.close()
+        _session = None