npm install react-native-fs --save

react-native link react-native-fs

import RNFS from 'react-native-fs';

/*下载文件*/
  downloadFile() {
    // On Android, use "RNFS.DocumentDirectoryPath" (MainBundlePath is not defined)

    // 图片
    // const downloadDest = `${RNFS.MainBundlePath}/${((Math.random() * 1000) | 0)}.jpg`;
    // const formUrl = 'http://img.kaiyanapp.com/c7b46c492261a7c19fa880802afe93b3.png"htmlcode">

 /*将文本写入本地 txt*/
  writeFile() {
    // create a path you want to write to
    const path = RNFS.MainBundlePath + '/test.txt';

    // write the file
    RNFS.writeFile(path, '这是一段文本，YES', 'utf8')
      .then((success) => {
        console.log('path', path);
      })
      .catch((err) => {
        console.log(err.message);
      });
  }




读取txt文件内容


/*读取txt文件内容*/
  readFile() {
    // create a path you want to delete
    const path = RNFS.MainBundlePath + '/test.txt';

    return RNFS.readFile(path)
      .then((result) => {
        console.log(result);

        this.setState({
          readTxtResult: result,
        })
      })
      .catch((err) => {
        console.log(err.message);

      });
  }




在已有的txt上添加新的文本


/*在已有的txt上添加新的文本*/
  appendFile() {
    const path = RNFS.MainBundlePath + '/test.txt';

    return RNFS.appendFile(path, '新添加的文本', 'utf8')
      .then((success) => {
        console.log('success');
      })
      .catch((err) => {
        console.log(err.message);

      });
  }




删除文件


  /*删除文件*/
  deleteFile() {
    // create a path you want to delete
    const path = RNFS.MainBundlePath + '/test.txt';

    return RNFS.unlink(path)
      .then(() => {
        console.log('FILE DELETED');
      })
      // `unlink` will throw an error, if the item to unlink does not exist
      .catch((err) => {
        console.log(err.message);
      });
  }



上传文件 only iOS


 /*上传文件 only iOS*/
  uploadFile() {
    const uploadSrc = `${RNFS.MainBundlePath}/test.txt`;

    const uploadUrl = 'http://buz.co/rnfs/upload-tester.php';

    const options = {
      toUrl: uploadUrl,
      files: [{name: 'myfile', filename: 'test.txt', filepath: uploadSrc, filetype: 'text/plain'}],
      background: true,
      method: 'POST', // PUT
      begin: (res) => {
        console.log('begin', res);
      },
      progress: (res) => {
        console.log('progress', res);
      }
    };

    const ret = RNFS.uploadFiles(options);

    return ret.promise.then(res => {
      const response = JSON.parse(res.body);
      console.log(response);

    })
      .catch(err => {
        console.log('err', err);
      });
  }




demo:https://github.com/chjwrr/RN-react-native-fs
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。