HarmonyOS 如何获取信号强度等信息

import radio from '@ohos.telephony.radio' 
import observer from '@ohos.telephony.observer'; 
 
// 以获取卡1的信号强度为例 
let slotId = 0; 
radio.getSignalInformation(slotId, (err, data) => { 
 if (!err) { 
  console.log("get signal information success."); 
  // 遍历数组，输出不同网络制式下的信号强度 
  for (let j = 0; j < data.length; j++) { 
   console.log("type:" + data[j].signalType + ", level:" + data[j].signalLevel); 
  } 
 } else { 
  console.log("get signal information fail, err is:" + JSON.stringify(err)); 
 } 
}); 
// 订阅蜂窝网络信号变化（可选） 
observer.on("signalInfoChange", (data) => { 
 console.log("signal info change, data is:" + JSON.stringify(data)); 
});