HarmonyOS 清理app缓存的方法

当前没有清除缓存的接口，推荐下面：查询缓存用storageStatistics.getCurrentBundleStats()接口。

清除文件缓存，需要调用context的cacheDir获取缓存，然后调用系统文件fs接口，判断是文件或者文件夹，再分别消除缓存。

详细用法见下面的链接：

查询：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-file-storage-statistics-V5

import { common } from '@kit.AbilityKit'
import fs from '@ohos.file.fs';
import { BusinessError } from '@kit.BasicServicesKit';

function clearCache(context:common.UIAbilityContext) {
  let cacheDir = context.cacheDir
  fs.listFile(cacheDir).then((filenames) => {
    for (let i = 0;i < filenames.length; i++) {
      let dirPath = cacheDir + filenames[i] // 判断是否文件夹
      let isDirectory: boolean = false
      try {
        isDirectory = fs.statSync(dirPath).isDirectory()
      } catch (e) {
        console.log(e)
      }
      if (isDirectory) {
        fs.rmdirSync(dirPath)
      } else {
        fs.unlink(dirPath).then(() => {
          console.info('remove file succeed');
        }).catch((err: BusinessError) => {
          console.info("remove file failed with error message: " + err.message + ", error code: " + err.code);
        });
      }
    }
  })
}