flutter 清除缓存

import 'dart:io';
import 'package:get/get.dart';
import 'package:oktoast/oktoast.dart';
import 'package:path_provider/path_provider.dart';
import 'package:toptongpin/app/utils/toast_util.dart';

class CacheUtil {
  static dynamic loadCache() async {
    try {
      final _tempDir = await getTemporaryDirectory();
      double value = await _getTotalSizeOfFilesInDir(_tempDir);
      /*tempDir.list(followLinks: false,recursive: true).listen((file){
          //打印每个缓存文件的路径
        print(file.path);
      });*/
      print('临时目录大小: ' + value.toString());
      return _renderSize(value);
    } catch (err) {
      print(err);
    }
  }

  ///递归方式删除目录
  static Future<Null> delDir(FileSystemEntity file) async {
    try {
      if (file is Directory) {
        final List<FileSystemEntity> children = file.listSync();
        for (final FileSystemEntity child in children) {
          await delDir(child);
        }
      }
      await file.delete();
    } catch (e) {
      print(e);
    }
  }

  static Future<double> _getTotalSizeOfFilesInDir(
      final FileSystemEntity file) async {
    try {
      if (file is File) {
        int length = await file.length();
        return double.parse(length.toString());
      }
      if (file is Directory) {
        final List<FileSystemEntity> children = file.listSync();
        double total = 0;
        if (children != null)
          for (final FileSystemEntity child in children)
            total += await _getTotalSizeOfFilesInDir(child);
        return total;
      }
      return 0;
    } catch (e) {
      print(e);
      return 0;
    }
  }

  ///格式化文件大小
  static _renderSize(double value) {
    List<String> unitArr = []
      ..add('B')
      ..add('K')
      ..add('M')
      ..add('G');
    int index = 0;
    while (value > 1024) {
      index++;
      value = value / 1024;
    }
    String size = value.toStringAsFixed(2);
    return size + unitArr[index];
  }

  static Future clearCache() async {
    //此处展示加载loading
    try {
      final _tempDir = await getTemporaryDirectory();
      double value = await _getTotalSizeOfFilesInDir(_tempDir);
      print("$value");
      if (value.toInt() <= 0) {
        ToastUtil.success('暂无缓存',position: ToastPosition.center);
        Get.back();
      } else if (value >= 0) {
        Get.back();
        ToastUtil.success('正在清理中···',position: ToastPosition.center);
        Future.delayed(Duration(seconds: 2), () async {
          //删除缓存目录
          await delDir(_tempDir);
          await loadCache();
          ToastUtil.success('清理缓存成功',position: ToastPosition.center);

        });
      }

    } catch (e) {
      print(e);
      ToastUtil.success('清除缓存失败');

    } finally {}
  }
}