HarmonyOS申请ohos.permission.READ_WRITE_DOWNLOAD_DIRECTORY权限没有弹窗

let atManager:abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager(); 
let state:boolean = false; 
// requestPermissionsFromUser会判断权限的授权状态来决定是否唤起弹窗 
atManager.requestPermissionsFromUser(context, 'ohos.permission.READ_WRITE_DOWNLOAD_DIRECTORY').then((data) => { 
  let grantStatus: Array<number> = data.authResults; 
  let length: number = grantStatus.length; 
  for (let i = 0; i < length; i++) { 
    if(grantStatus[i] == 0){ 
      state = true; 
    }else { 
      // 用户拒绝授权，提示用户必须授权才能访问当前页面的功能，并引导用户到系统设置中打开相应的权限 
      state = false; 
      return; 
    } 
  } 
}).catch((err: BusinessError)=>{ 
  state = false; 
  console.error(`requestPermissionsFromUser failed, code is ${err.code}, message is ${err.message}`); 
})