HarmonyOS 鸿蒙Next 怎么能取出App写到沙箱环境中的日志文件？

您可通过对文件进行拷贝来获取

let srcPath = pathDir + "/srcDir/test.txt";
let dstPath = pathDir + "/dstDir/test.txt";
fs.copyFileSync(srcPath,dstPath);

或者参考如下代码：

import buffer from '@ohos.buffer';
import fs from '@ohos.file.fs';
import picker from '@ohos.file.picker';
import { BusinessError } from '@ohos.base';

@Entry
@Component

struct Index {
  @State imageBuffer: ArrayBuffer = new ArrayBuffer(96)
  @State audioUrl: string = ""
  @State audioSaveResult: string = ""

  build() {
    Row() {
      Column() {
        Text("写文件")
        .onClick(() => {
          // 写入
        })

        Text("pcmPickerSave")
          .fontSize(30)
          .fontWeight(FontWeight.Bold)
          .onClick(async () => {
            const audioSaveOptions = new picker.AudioSaveOptions(); // 创建文件管理器选项实例
            audioSaveOptions.newFileNames = ['AudioViewPicker.pcm']; // 保存文件名（可选）
            const audioViewPicker = new picker.AudioViewPicker();
            audioViewPicker.save(audioSaveOptions).then((audioSelectResult: Array<string>) => {
              this.audioSaveResult = audioSelectResult[0];
              console.info('audioViewPicker.save to file succeed and uri is:' + this.audioSaveResult);
            }).catch((err: BusinessError) => {
              console.error(`Invoke audioViewPicker.save failed, code is ${err.code}, message is ${err.message}`);
            })
          })

        Text("pcmSave")
          .fontSize(30)
          .fontWeight(FontWeight.Bold)
          .onClick(async () => {
            try {
              this.imageBuffer = buffer.from("hello word").buffer
              //使用读取的buffet保存
              let file2 = fs.openSync(this.audioSaveResult, fs.OpenMode.READ_WRITE);
              let writeLen = await fs.write(file2.fd, this.imageBuffer);
              fs.closeSync(file2);
              console.info("msgXucan [picker] writeOnly writeLen = " + writeLen);
              AlertDialog.show({ message: '已保存至本地!' });
            } catch (error) {
              let err: BusinessError = error as BusinessError;
              console.info("[picker] writeOnly error: " + JSON.stringify(err));
            }
          })
      }.width('100%')
      .height('100%')
    }
    .height('100%')
  }
}

通过filePick的方式写入到公共文件目录，然后通过hdc命令或者ide取出到电脑