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关于做ppt的网站有哪些内容,山东济宁做网站的公司有哪些,甘肃省通信管理局网站备案,网络营销成功案例Flutter中的网络请求图片存储为缓存，与定制删除本地缓存 1：封装请求图片函数 2：访问的图片都会转为本地缓存，当相同的请求url，会在本地调用图片 3：本地缓存管理【windows与andriod已经测试】【有页面】【有…

Flutter中的网络请求图片存储为缓存，与定制删除本地缓存
1：封装请求图片函数
2：访问的图片都会转为本地缓存，当相同的请求url，会在本地调用图片
3：本地缓存管理【windows与andriod已经测试】【有页面】【有调用案例】
4：删除本地缓存

清理缓存页面（下方代码中已包括）
在这里插入图片描述

在这里插入图片描述

windows中显示图片-----------安卓中显示图片
这里还没有进行优化图片显示的宽高，圆角，请自行设置
在这里插入图片描述

打印日志（显示图片请求的获取过程与报错原因）

在这里插入图片描述

TuPianJiaZai 图片加载工具使用教程

注意事项

imageUrl 可以为 null，此时会显示空白
图片会自动缓存到本地
支持自动重试3次
默认有加载动画和错误提示
支持所有标准图片格式

实际应用场景

商品展示卡片
用户头像
图片列表
背景图片
Banner图片

1. 基本用法

1.1导入文件

import '../utils/get_images/tupianjiazai.dart';

TuPianJiaZai.jiazaiTupian(imageUrl: product.image,width: double.infinity,height: 200,fit: BoxFit.cover,
)

2. 完整参数说明

TuPianJiaZai.jiazaiTupian(// 必需参数imageUrl: String?, // 图片URL，可以为null// 可选参数width: double?, // 显示宽度height: double?, // 显示高度fit: BoxFit, // 图片填充方式，默认BoxFit.covercacheWidth: int?, // 缓存图片宽度，用于优化内存cacheHeight: int?, // 缓存图片高度，用于优化内存placeholder: Widget?, // 加载时显示的占位WidgeterrorWidget: Widget?, // 加载失败时显示的Widget
)

3. 使用案例

3.1 基础加载

TuPianJiaZai.jiazaiTupian(imageUrl: 'https://example.com/image.jpg',width: 200,height: 200,
)

3.2 自定义占位图和错误图

TuPianJiaZai.jiazaiTupian(imageUrl: imageUrl,width: 300,height: 200,placeholder: const Center(child: CircularProgressIndicator(),),
errorWidget: const Center(child: Column(mainAxisAlignment: MainAxisAlignment.center,children: [Icon(Icons.error),Text('加载失败'),],),),
)

3.3 列表项中使用

ListView.builder(
itemBuilder: (context, index) {
return TuPianJiaZai.jiazaiTupian(
imageUrl: imageUrls[index],
height: 150,
fit: BoxFit.cover,
cacheWidth: 600, // 优化缓存大小
cacheHeight: 400,
);
},
)

请自行在\lib\utils\get_images\文件夹中创建一下配置

D:\F\luichun\lib\utils\get_images\huancunguanli.dart

import 'dart:io';
import 'dart:typed_data';
import 'package:path_provider/path_provider.dart';
import 'package:crypto/crypto.dart';
import 'dart:convert';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:synchronized/synchronized.dart';
import 'logger.dart';  // 使用统一的日志管理器
import '../env_config.dart';// 本地进行开发时，使用 会对 localhost:10005 进行请求，但是安卓模拟器需要把localhost转换为 10.0.2.2/// 完整工作流程：
/// 1.应用启动 -> 初始化缓存目录
/// 2.请求图片 -> 检查缓存 -> 返回缓存或null
/// 3.下载图片 -> 保存图片 -> 更新映射关系
/// 4.定期维护 -> 清理缓存/计算大小/// 图片缓存管理器
/// 用于管理图片的本地缓存，减少重复的网络请求
class HuanCunGuanLi {/// 单例模式///   使用工厂构造函数确保全局只有一个缓存管理器实例///   避免重复创建缓存目录和资源浪费static final HuanCunGuanLi _instance = HuanCunGuanLi._internal();/// 缓存目录Directory? _cacheDir;/// 初始化锁final _lock = Lock();/// 初始化标志bool _isInitialized = false;/// 持久化存储的键名static const String _prefKey = 'image_cache_urls';// 工厂构造函数factory HuanCunGuanLi() {return _instance;}// 私有构造函数HuanCunGuanLi._internal();/// 确保已初始化Future<void> _ensureInitialized() async {if (_isInitialized) return;  // 快速检查await _lock.synchronized(() async {if (_isInitialized) return;  // 双重检查await init();});}/// 初始化缓存目录Future<void> init() async {try {final appDir = await getApplicationDocumentsDirectory();final cacheDir = Directory('${appDir.path}/image_cache');if (!await cacheDir.exists()) {await cacheDir.create(recursive: true);}_cacheDir = cacheDir;_isInitialized = true;if (EnvConfig.isDevelopment) {ImageLogger.logCacheInfo('缓存系统初始化完成: ${_cacheDir!.path}');}} catch (e) {ImageLogger.logCacheError('缓存系统初始化失败', error: e);rethrow;}}/// 3异步获取缓存图片/// 参数:///   url: 图片的网络地址/// 返回:///   Uint8List?: 图片的二进制数据，不存在时返回null/// 流程:///   1. 根据URL生成缓存键///   2. 查找本地缓存文件///   3. 返回缓存数据或nullFuture<Uint8List?> huoquTupian(String url) async {await _ensureInitialized();try {final cacheKey = _shengchengKey(url);final cacheFile = File('${_cacheDir!.path}/$cacheKey');if (await cacheFile.exists()) {ImageLogger.logCacheDebug('从缓存加载图片', {'url': url});return await cacheFile.readAsBytes();}return null;} catch (e) {ImageLogger.logCacheError('读取缓存图片失败', error: e);return null;}}/// 异步保存图片到缓存/// [url] 图片URL/// [imageBytes] 图片二进制数据Future<void> baocunTupian(String url, Uint8List imageBytes) async {await _ensureInitialized();final cacheKey = _shengchengKey(url);final cacheFile = File('${_cacheDir!.path}/$cacheKey');await cacheFile.writeAsBytes(imageBytes);await _baocunURLyingshe(url, cacheKey);}/// 生成缓存键/// 使用MD5加密URL生成唯一标识String _shengchengKey(String url) {final bytes = utf8.encode(url);final digest = md5.convert(bytes);return digest.toString();}/// 4. URL 映射管理：/// 保存URL映射关系/// 实现:///   1. 获取SharedPreferences实例///   2. 读取现有映射///   3. 更新映射关系///   4. 序列化并保存///   使用 SharedPreferences 持久化存储 URL 映射关系///   JSON 序列化保存映射数据///   异步操作避免阻塞主线程/// 保存URL映射关系Future<void> _baocunURLyingshe(String url, String cacheKey) async {final prefs = await SharedPreferences.getInstance();final Map<String, String> urlMap = await _huoquURLyingshe();urlMap[url] = cacheKey;await prefs.setString(_prefKey, jsonEncode(urlMap));}/// 获取URL映射关系Future<Map<String, String>> _huoquURLyingshe() async {final prefs = await SharedPreferences.getInstance();final String? mapJson = prefs.getString(_prefKey);if (mapJson != null) {return Map<String, String>.from(jsonDecode(mapJson));}return {};}/// 5.缓存清理功能：/// 清除所有缓存/// 使用场景:///   1. 应用清理存储空间///   2. 图片资源更新///   3. 缓存出现问题时重置/// 递归删除缓存目录/// 清除 URL 映射数据/// 清除所有缓存Future<void> qingchuHuancun() async {await _cacheDir!.delete(recursive: true);await _cacheDir!.create();final prefs = await SharedPreferences.getInstance();await prefs.remove(_prefKey);}///6 .缓存大小计算：///- 异步遍历缓存目录/// 累计所有文件大小/// 使用 Stream 处理大目录/// 获取缓存大小（字节）Future<int> huoquHuancunDaxiao() async {int size = 0;await for (final file in _cacheDir!.list()) {if (file is File) {size += await file.length();}}return size;}
}

D:\F\luichun\lib\utils\get_images\logger.dart

import 'package:logger/logger.dart';/// 图片加载系统的日志管理器
class ImageLogger {static final Logger _logger = Logger(printer: PrettyPrinter(methodCount: 0,errorMethodCount: 8,lineLength: 120,colors: true,printEmojis: true,dateTimeFormat: DateTimeFormat.onlyTimeAndSinceStart,),);// 缓存系统日志static void logCacheInfo(String message) {_logger.i('📦 $message');}static void logCacheError(String message, {dynamic error}) {_logger.e('📦 $message', error: error);}static void logCacheDebug(String message, [Map<String, dynamic>? data]) {if (data != null) {_logger.d('📦 $message\n${_formatData(data)}');} else {_logger.d('📦 $message');}}// 图片加载日志static void logImageInfo(String message) {_logger.i('🖼️ $message');}static void logImageError(String message, {dynamic error}) {_logger.e('🖼️ $message', error: error);}static void logImageDebug(String message, [Map<String, dynamic>? data]) {if (data != null) {_logger.d('🖼️ $message\n${_formatData(data)}');} else {_logger.d('🖼️ $message');}}static void logImageWarning(String message, [Map<String, dynamic>? data]) {if (data != null) {_logger.w('🖼️ $message\n${_formatData(data)}');} else {_logger.w('🖼️ $message');}}// 格式化数据为字符串static String _formatData(Map<String, dynamic> data) {return data.entries.map((e) => '  ${e.key}: ${e.value}').join('\n');}
}

D:\F\luichun\lib\utils\get_images\qinglihuancun.dart

// import 'package:flutter/material.dart';
import 'huancunguanli.dart';
import 'logger.dart';/// 缓存清理管理器
class QingLiHuanCun {static final HuanCunGuanLi _huancun = HuanCunGuanLi();/// 清理所有缓存static Future<void> qingliSuoyou() async {try {await _huancun.qingchuHuancun();ImageLogger.logCacheInfo('缓存清理完成');} catch (e) {ImageLogger.logCacheError('缓存清理失败', error: e);}}/// 获取当前缓存大小static Future<String> huoquDaxiao() async {try {final size = await _huancun.huoquHuancunDaxiao();// 转换为合适的单位if (size < 1024) return '$size B';if (size < 1024 * 1024) return '${(size / 1024).toStringAsFixed(2)} KB';return '${(size / (1024 * 1024)).toStringAsFixed(2)} MB';} catch (e) {ImageLogger.logCacheError('获取缓存大小失败', error: e);return '未知';}}/// 检查缓存大小并在超过阈值时清理static Future<void> jianchaHeQingli() async {try {final size = await _huancun.huoquHuancunDaxiao();// 如果缓存超过550MB，则清理if (size > 550 * 1024 * 1024) {await qingliSuoyou();}} catch (e) {ImageLogger.logCacheError('缓存检查失败', error: e);}}
}

D:\F\luichun\lib\utils\get_images\qinglihuancundeanniu.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'dart:async';
import 'qinglihuancun.dart';/// 缓存配置
class CacheConfig {// 警告阈值  (当缓存超过500MB时显示警告)static const double warningThresholdMB = 500.0;// 自动清理阈值static const double autoCleanThresholdMB = 550.0;// 动画时长static const Duration animationDuration = Duration(milliseconds: 300);// 提示显示时长static const Duration snackBarDuration = Duration(seconds: 3);// 刷新动画时长static const Duration refreshAnimationDuration = Duration(milliseconds: 200);
}/// 清理完成回调
typedef OnCleanComplete = void Function(bool success);/// 缓存监听器
class CacheListener {static final List<VoidCallback> _listeners = [];static void addListener(VoidCallback listener) {_listeners.add(listener);}static void removeListener(VoidCallback listener) {_listeners.remove(listener);}static void notifyListeners() {for (var listener in _listeners) {listener();}}
}/// 自动清理调度器
class AutoCleanScheduler {static Timer? _timer;// 每24小时自动检查一次static void startSchedule() {_timer?.cancel();_timer = Timer.periodic(const Duration(hours: 24),(_) => QingLiHuanCun.jianchaHeQingli(),);}static void stopSchedule() {_timer?.cancel();_timer = null;}
}/// 缓存管理页面
class CacheManagementScreen extends StatelessWidget {const CacheManagementScreen({super.key});@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: const Text('缓存管理'),elevation: 0,),body: const SingleChildScrollView(child: QingLiHuanCunAnNiu(),),);}
}/// 缓存清理按钮组件
class QingLiHuanCunAnNiu extends StatefulWidget {final OnCleanComplete? onCleanComplete;const QingLiHuanCunAnNiu({super.key,this.onCleanComplete,});@overrideState<QingLiHuanCunAnNiu> createState() => _QingLiHuanCunAnNiuState();
}class _QingLiHuanCunAnNiuState extends State<QingLiHuanCunAnNiu> {String _cacheSize = '计算中...';bool _isClearing = false;Timer? _autoCheckTimer;DateTime? _lastClickTime;bool _isDoubleClick = false;@overridevoid initState() {super.initState();_initializeCache();}@overridevoid dispose() {_autoCheckTimer?.cancel();AutoCleanScheduler.stopSchedule();super.dispose();}// 初始化缓存Future<void> _initializeCache() async {await _huoquDaxiao();_startAutoCheck();AutoCleanScheduler.startSchedule();}// 启动自动检查// 每30分钟检查一次缓存大小void _startAutoCheck() {_autoCheckTimer?.cancel();_autoCheckTimer = Timer.periodic(const Duration(minutes: 30),(_) => _huoquDaxiao(),);}// 显示错误信息void _showError(String message) {if (!mounted) return;ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Row(children: [const Icon(Icons.error_outline, color: Colors.white),const SizedBox(width: 12),Expanded(child: Text(message)),],),backgroundColor: Colors.red,behavior: SnackBarBehavior.floating,duration: CacheConfig.snackBarDuration,shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8),),),);}// 显示警告信息void _showWarning() {if (!mounted) return;ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Row(children: [const Icon(Icons.warning_amber_rounded, color: Colors.white),const SizedBox(width: 12),const Expanded(child: Text('缓存较大，建议清理')),],),backgroundColor: Colors.orange,duration: CacheConfig.snackBarDuration,behavior: SnackBarBehavior.floating,shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8),),),);}// 获取缓存大小并检查Future<void> _huoquDaxiao() async {try {final size = await QingLiHuanCun.huoquDaxiao();if (!mounted) return;setState(() => _cacheSize = size);_checkCacheWarning(size);CacheListener.notifyListeners();} catch (e) {_showError('获取缓存大小失败: $e');}}// 检查缓存大小并显示警告void _checkCacheWarning(String size) {if (!size.contains('MB')) return;try {final double sizeInMB = double.parse(size.split(' ')[0]);if (sizeInMB > CacheConfig.warningThresholdMB) {_showWarning();}} catch (e) {// 解析错误处理}}// 显示清理进度void _showCleaningProgress() {if (!mounted) return;ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Row(children: [const SizedBox(width: 20,height: 20,child: CircularProgressIndicator(strokeWidth: 2,valueColor: AlwaysStoppedAnimation<Color>(Colors.white),),),const SizedBox(width: 16),const Text('正在清理缓存...'),],),duration: const Duration(seconds: 1),behavior: SnackBarBehavior.floating,shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8),),),);}// 检查是否是快速双击bool _checkDoubleClick() {final now = DateTime.now();if (_lastClickTime != null) {final difference = now.difference(_lastClickTime!);if (difference.inMilliseconds <= 1000) {  // 1秒内的双击_isDoubleClick = true;return true;}}_lastClickTime = now;_isDoubleClick = false;return false;}// 修改确认对话框逻辑Future<bool> _showConfirmDialog() async {if (_isClearing) return false;  // 防止重复清理// 检查是否是快速双击final isDoubleClick = _checkDoubleClick();// 如果不是双击，且缓存小于100MB，显示无需清理提示if (!isDoubleClick && _cacheSize.contains('MB')) {try {final double sizeInMB = double.parse(_cacheSize.split(' ')[0]);if (sizeInMB < 100.0) {// 显示缓存较小的提示if (mounted) {ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Row(children: [const Icon(Icons.info_outline, color: Colors.white),const SizedBox(width: 12),const Expanded(child: Text('缓存小于100MB，暂无需清理\n(快速双击可强制清理)'),),],),backgroundColor: Colors.blue,behavior: SnackBarBehavior.floating,duration: const Duration(seconds: 2),shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8),),),);}return false;}} catch (e) {// 解析错误处理}}// 原有的确认对话框逻辑HapticFeedback.mediumImpact();final bool? confirm = await showDialog<bool>(context: context,builder: (context) => AlertDialog(title: Row(children: [const Icon(Icons.delete_outline, color: Colors.red),const SizedBox(width: 12),Text(_isDoubleClick ? '强制清理' : '确认清理'),],),content: Column(mainAxisSize: MainAxisSize.min,crossAxisAlignment: CrossAxisAlignment.start,children: [Text('当前缓存大小: $_cacheSize'),const SizedBox(height: 8),Text(_isDoubleClick ? '您选择了强制清理，确定要清理所有缓存吗？': '清理后将需要重新下载图片，确定要清理吗？'),],),actions: [TextButton(onPressed: () {HapticFeedback.lightImpact();Navigator.pop(context, false);},child: const Text('取消'),),TextButton(onPressed: () {HapticFeedback.lightImpact();Navigator.pop(context, true);},style: TextButton.styleFrom(foregroundColor: Colors.red,),child: Text(_isDoubleClick ? '强制清理' : '清理'),),],),);return confirm ?? false;}// 清理缓存Future<void> _qingliHuancun() async {final bool confirmed = await _showConfirmDialog();if (!confirmed) return;setState(() => _isClearing = true);try {_showCleaningProgress();await QingLiHuanCun.qingliSuoyou();if (mounted) {ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Row(children: [const Icon(Icons.check_circle_outline, color: Colors.white),const SizedBox(width: 12),const Text('缓存清理完成'),],),backgroundColor: Colors.green,behavior: SnackBarBehavior.floating,shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8),),),);await _huoquDaxiao();widget.onCleanComplete?.call(true);}} catch (e) {if (mounted) {_showError('清理失败: $e');widget.onCleanComplete?.call(false);}} finally {if (mounted) {setState(() => _isClearing = false);}}}@overrideWidget build(BuildContext context) {return Padding(padding: const EdgeInsets.all(16.0),child: Column(crossAxisAlignment: CrossAxisAlignment.stretch,children: [// 显示缓存大小Card(elevation: 0,shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12),side: BorderSide(color: Colors.grey.withOpacity(0.2),),),child: Padding(padding: const EdgeInsets.all(16.0),child: Column(crossAxisAlignment: CrossAxisAlignment.start,children: [const Text('缓存大小',style: TextStyle(fontSize: 16,fontWeight: FontWeight.bold,),),const SizedBox(height: 8),Row(mainAxisAlignment: MainAxisAlignment.spaceBetween,children: [Text(_cacheSize,style: const TextStyle(fontSize: 24,fontWeight: FontWeight.bold,),),IconButton(icon: AnimatedRotation(duration: CacheConfig.refreshAnimationDuration,turns: _isClearing ? 1 : 0,child: const Icon(Icons.refresh),),onPressed: _isClearing ? null : () async {try {setState(() => _isClearing = true);HapticFeedback.lightImpact();// 显示刷新提示ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Row(children: [SizedBox(width: 16,height: 16,child: CircularProgressIndicator(strokeWidth: 2,valueColor: AlwaysStoppedAnimation<Color>(Colors.white),),),SizedBox(width: 12),Text('正在刷新...'),],),duration: Duration(milliseconds: 200),behavior: SnackBarBehavior.floating,),);await _huoquDaxiao();} finally {if (mounted) {setState(() => _isClearing = false);}}},),],),],),),),const SizedBox(height: 16),// 清理按钮AnimatedContainer(duration: CacheConfig.animationDuration,transform: Matrix4.translationValues(0, _isClearing ? 4 : 0, 0,),child: ElevatedButton(onPressed: _isClearing ? null : () {HapticFeedback.mediumImpact();_qingliHuancun();},style: ElevatedButton.styleFrom(padding: const EdgeInsets.symmetric(vertical: 16),shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12),),),child: _isClearing? const SizedBox(width: 20,height: 20,child: CircularProgressIndicator(strokeWidth: 2),): const Text('清理缓存',style: TextStyle(fontSize: 16),),),),const SizedBox(height: 16),// 自动清理设置Card(elevation: 0,shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12),side: BorderSide(color: Colors.grey.withOpacity(0.2),),),child: ListTile(leading: const Icon(Icons.auto_delete),title: const Text('自动清理'),subtitle: Text('当缓存超过${CacheConfig.autoCleanThresholdMB}MB时自动清理'),trailing: const Icon(Icons.chevron_right),onTap: _isClearing ? null : () async {HapticFeedback.lightImpact();await QingLiHuanCun.jianchaHeQingli();await _huoquDaxiao();},),),],),);}
}

D:\F\luichun\lib\utils\get_images\tupianjiazai.dart

import 'package:flutter/material.dart';
import 'package:dio/dio.dart';
import 'dart:typed_data';
import 'huancunguanli.dart';
import '../env_config.dart';
import 'dart:isolate';
import 'logger.dart';/// 图片加载器类
/// 功能：处理异步图片加载、缓存和显示
/// 工作流程：
///   1. 接收图片URL请求
///   2. 检查本地缓存
///   3. 如无缓存，则在独立isolate中下载
///   4. 下载完成后保存到缓存
///   5. 返回图片数据用于显示
class TuPianJiaZai {static final HuanCunGuanLi _huancun = HuanCunGuanLi();static bool _initialized = false;/// 内部初始化方法/// 确保只初始化一次static Future<void> _ensureInitialized() async {if (!_initialized) {await _huancun.init();_initialized = true;ImageLogger.logCacheInfo('图片加载系统初始化完成');}}/// 网络请求客户端配置/// 功能：配置网络请求的基本参数/// 参数说明：///   - connectTimeout: 连接超时时间///   - receiveTimeout: 接收超时时间///   - headers: 请求头配置///   - followRedirects: 是否跟随重定向///   - maxRedirects: 最大重定向次数///   - validateStatus: 状态验证函数static final Dio _dio = Dio(BaseOptions(connectTimeout: const Duration(seconds: 30),receiveTimeout: const Duration(seconds: 60),sendTimeout: const Duration(seconds: 30),headers: {'Accept': 'image/webp,image/apng,image/*,*/*;q=0.8','Accept-Encoding': 'gzip, deflate','Connection': 'keep-alive',},followRedirects: true,maxRedirects: 5,validateStatus: (status) => status != null && status < 500,responseType: ResponseType.bytes,receiveDataWhenStatusError: true,));/// 在独立isolate中加载图片/// 功能：创建新的isolate来处理图片下载，避免阻塞主线程/// 参数：///   url: 图片的网络地址/// 返回：///   Uint8List?: 图片的二进制数据，下载失败返回null/// 工作流程：///   1. 创建ReceivePort接收数据///   2. 启动新isolate处理下载///   3. 等待结果返回static Future<Uint8List?> _loadInIsolate(String url) async {final receivePort = ReceivePort();await Isolate.spawn(_isolateFunction, {'url': url,'sendPort': receivePort.sendPort,});final result = await receivePort.first;return result as Uint8List?;}/// Isolate工作函数/// 功能：在独立isolate中执行图片下载/// 参数：///   data: 包含url和sendPort的Map/// 工作流程：///   1. 解析传入参数///   2. 执行图片下载///   3. 通过sendPort返回结果static void _isolateFunction(Map<String, dynamic> data) async {final String url = data['url'];final SendPort sendPort = data['sendPort'];try {ImageLogger.logImageDebug('开始下载图片', {'url': url});int retryCount = 3;Response<List<int>>? response;while (retryCount > 0) {try {response = await _dio.get<List<int>>(EnvConfig.getImageUrl(url),options: Options(responseType: ResponseType.bytes,headers: {'Range': 'bytes=0-','Connection': 'keep-alive',},),onReceiveProgress: (received, total) {if (EnvConfig.isDevelopment) {ImageLogger.logImageDebug('下载进度', {'received': received, 'total': total});}},);break;} catch (e) {retryCount--;if (retryCount > 0) {ImageLogger.logImageWarning('图片下载失败，准备重试', {'url': url,'remainingRetries': retryCount,'error': e.toString()});await Future.delayed(Duration(seconds: 2));} else {rethrow;}}}if (response != null && (response.statusCode == 200 || response.statusCode == 206) && response.data != null) {final imageBytes = Uint8List.fromList(response.data!);sendPort.send(imageBytes);} else {ImageLogger.logImageWarning('图片下载失败', {'statusCode': response?.statusCode,'message': response?.statusMessage});sendPort.send(null);}} catch (e) {ImageLogger.logImageError('图片下载异常', error: e);sendPort.send(null);}}/// 加载网络图片的Widget/// 功能：提供图片加载的Widget封装/// 参数：///   imageUrl: 图片URL///   width: 显示宽度///   height: 显示高度///   fit: 图片填充方式///   placeholder: 加载占位Widget///   errorWidget: 错误显示Widget///   cacheWidth: 缓存宽度///   cacheHeight: 缓存高度/// 工作流程：///   1. 检查URL是否有效///   2. 使用FutureBuilder处理异步加载///   3. 根据不同状态显示不同Widgetstatic Widget jiazaiTupian({required String? imageUrl,double? width,double? height,BoxFit fit = BoxFit.cover,Widget? placeholder,Widget? errorWidget,int? cacheWidth,int? cacheHeight,}) {// 在实际使用时自动初始化_ensureInitialized();if (imageUrl == null) {return const SizedBox.shrink();}return FutureBuilder<Uint8List?>(future: _jiazaiTupianShuju(imageUrl),builder: (context, snapshot) {if (snapshot.connectionState == ConnectionState.waiting) {return placeholder ?? SizedBox(width: width,height: height,child: const Center(child: CircularProgressIndicator()),);}if (snapshot.hasError || snapshot.data == null) {if (EnvConfig.isDevelopment) {print('图片加载失败: ${snapshot.error}');print('URL: $imageUrl');}return errorWidget ?? SizedBox(width: width,height: height,child: const Center(child: Column(mainAxisAlignment: MainAxisAlignment.center,children: [Icon(Icons.broken_image),Text('图片加载失败，请稍后重试'),],),),);}return Image.memory(snapshot.data!,key: ValueKey(imageUrl),width: width,height: height,fit: fit,cacheWidth: cacheWidth ?? (width?.toInt()),cacheHeight: cacheHeight ?? (height?.toInt()),gaplessPlayback: true,);},);}/// 加载图片数据/// 功能：处理图片加载的核心逻辑/// 参数：///   url: 图片URL/// 返回：///   Uint8List?: 图片二进制数据/// 工作流程：///   1. 检查本地缓存///   2. 如有缓存直接返回///   3. 无缓存则下载并保存static Future<Uint8List?> _jiazaiTupianShuju(String url) async {// 在实际使用时自动初始化await _ensureInitialized();final huancun = HuanCunGuanLi();// 先从缓存获取final cachedImage = await huancun.huoquTupian(url);if (cachedImage != null) {if (EnvConfig.isDevelopment) {print('从缓存加载图片: $url');}return cachedImage;}// 在独立isolate中加载图片final imageBytes = await _loadInIsolate(url);if (imageBytes != null) {// 保存到缓存await huancun.baocunTupian(url, imageBytes);}return imageBytes;}
}