HarmonyOS 鸿蒙Next中如何获取手机里的txt和word文本

通过@kit.FileManagementKit的documentViewPicker接口选择文件，示例代码如下

import { documentViewPicker } from '[@kit](/user/kit).FileManagementKit';

async function selectFile() {
  let picker = new documentViewPicker.DocumentViewPicker();
  let options = {
    types: ['text/plain', 'application/msword'], // 指定需要选择的文件类型
  };
  try {
    let fileList = await picker.select(options);
    if (fileList.length > 0) {
      return fileList.uri; // 获取选中文件的URI
    }
  } catch (error) {
    console.error('选择文件失败:', error);
  }
}

可以参考这个

import { common } from '@kit.AbilityKit';
import { picker } from '@kit.CoreFileKit';
import { BusinessError } from '@kit.BasicServicesKit';
import fs from '@ohos.file.fs';
import { buffer } from '@kit.ArkTS';

@Entry
@Component
struct PagePickerDocument {
  @State message: string = 'Hello World';

  build() {
    RelativeContainer() {
      Text(this.message)
        .id('PagePickerDocumentHelloWorld')
        .fontSize($r('app.float.page_text_font_size'))
        .fontWeight(FontWeight.Bold)
        .alignRules({
          center: { anchor: '__container__', align: VerticalAlign.Center },
          middle: { anchor: '__container__', align: HorizontalAlign.Center }
        })
        .onClick(async () => {
          this.message = 'Welcome';
          let context = this.getUIContext().getHostContext() as common.UIAbilityContext; // 请确保this.getUIContext().getHostContext()返回结果为UIAbilityContext
          let documentPicker = new picker.DocumentViewPicker(context);
          let documentSelectOptions = new picker.DocumentSelectOptions();
          documentSelectOptions.fileSuffixFilters = ['txt']
          documentPicker.select(documentSelectOptions).then((documentSelectResult: Array<string>) => {
            console.info('DocumentViewPicker.select successfully, documentSelectResult uri: ' + JSON.stringify(documentSelectResult));
            let uri: string = documentSelectResult[0];
            // 这里需要注意接口权限参数是fs.OpenMode.READ_ONLY。
            try {
              let file = fs.openSync(uri, fs.OpenMode.READ_ONLY);
              let arrayBuffer = new ArrayBuffer(1024);
              let content = '';
              let readLen = 0;
              do {
                readLen = fs.readSync(file.fd, arrayBuffer);
                content += buffer.from(arrayBuffer, 0, readLen).toString();
              } while (readLen > 0);
              fs.closeSync(file)
              console.info(content)
            } catch (error) {
              // TODO: Implement error handling.
            }
          }).catch((err: BusinessError) => {
            console.error(`DocumentViewPicker.select failed with err, code is: ${err.code}, message is: ${err.message}`);
          });
        })
    }
    .height('100%')
    .width('100%')
  }
}