如何解决文件的中文乱码问题

import { util } from "@kit.ArkTS" 
import { fileIo } from '@kit.CoreFileKit'; 
 
let filePath = getContext(this).filesDir + "/test0.txt"; 
let stream = fileIo.createStreamSync(filePath, "r+"); 
let buffer = new ArrayBuffer(4096); 
let readOut = stream.readSync(buffer); 
let textDecoder = util.TextDecoder.create('utf-8', { ignoreBOM: true }); 
let readString = textDecoder.decodeWithStream(new Uint8Array(buffer), { stream: false }); 
console.log("读取的文件内容：" + readString);

import { util } from '@kit.ArkTS';
import { fileIo } from '@kit.CoreFileKit';

let filePath = getContext(this).filesDir + "/test0.txt";
let file = fileIo.openSync(filePath, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE);

let writeLen = fileIo.writeSync(file.fd, "你好，世界");
fileIo.closeSync(file);
console.info(`GarbledCnCharacters The length of str is: ${writeLen}`);
let stream = fileIo.createStreamSync(filePath, "r+");
let buffer = new ArrayBuffer(4096);
stream.readSync(buffer);

let textDecoder = util.TextDecoder.create('utf-8', { ignoreBOM: true });

let readString = textDecoder.decodeWithStream(new Uint8Array(buffer), { stream: false });
console.info(`GarbledCnCharacters read content is:${readString}`);