HarmonyOS 如何进行文本文件读取？

import { common } from '@kit.AbilityKit'; 
import { BusinessError } from '@ohos.base'; 
import util from '@ohos.util'; 
 
function   certVerification(context: common.UIAbilityContext){ 
  try { 
    context.resourceManager.getRawFileContent("test.txt", (error: BusinessError, value: Uint8Array) => { 
      if (error != null) { 
        console.error("error is " + error); 
      } else { 
        let rawFile = value; 
        const result=util.TextDecoder.create().decodeWithStream(rawFile) 
        console.info('result:'+result) 
      } 
    }); 
  } catch (error) { 
    let code = (error as BusinessError).code; 
    let message = (error as BusinessError).message; 
    console.error(`callback getRawFileContent failed, error code: ${code}, message: ${message}.`); 
  } 
} 
 
 
@Entry 
@Component 
struct Index { 
  private context=getContext(this) as common.UIAbilityContext; 
  build() { 
    Button('测试rawfile') 
      .onClick(()=>{ 
        certVerification(this.context) 
      }) 
  } 
}