react-native-fs实现文件下载、文本存储的示例代码

本文内容：

react-native-fs的简单使用

1. 下载文件(图片、文件、视频、音频)
2. 将文本写入本地 txt
3. 读取txt文件内容
4. 在已有的txt上添加新的文本
5. 删除文件
6. 上传文件 only ios

github链接:

另外还有一个下载的库 ：

安装步骤

第一步：

npm install react-native-fs --save

第二步：

react-native link react-native-fs

ok 即可开始使用(不放心的可以按照github上的对比一下)

简单使用

import rnfs from 'react-native-fs';

下载文件

/*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?imagemogr2/quality/60/format/jpg';

    // 文件
    // const downloaddest = `${rnfs.mainbundlepath}/${((math.random() * 1000) | 0)}.zip`;
    // const formurl = 'http://files.cnblogs.com/zhuqil/uiwebviewdemo.zip';

    // 视频
    // const downloaddest = `${rnfs.mainbundlepath}/${((math.random() * 1000) | 0)}.mp4`;
    // http://gslb.miaopai.com/stream/sny~bbkqbi2ulebmxhxgqnnkqyig9ub8.mp4?vend=miaopai&
    // https://gslb.miaopai.com/stream/bnaeyol-tewsraiybnpdr03ddlfavowd.mp4?vend=miaopai&
    // const formurl = 'https://gslb.miaopai.com/stream/9q5adap2v5nhtqieqt7t461vknpxvc2t.mp4?vend=miaopai&';

    // 音频
    const downloaddest = `${rnfs.mainbundlepath}/${((math.random() * 1000) | 0)}.mp3`;
    // http://wvoice.spriteapp.cn/voice/2015/0902/55e6fc6e4f7b9.mp3
    const formurl = 'http://wvoice.spriteapp.cn/voice/2015/0818/55d2248309b09.mp3';

    const options = {
      fromurl: formurl,
      tofile: downloaddest,
      background: true,
      begin: (res) => {
        console.log('begin', res);
        console.log('contentlength:', res.contentlength / 1024 / 1024, 'm');
      },
      progress: (res) => {

        let pro = res.byteswritten / res.contentlength;

        this.setstate({
          progressnum: pro,
        });
      }
    };
    try {
      const ret = rnfs.downloadfile(options);
      ret.promise.then(res => {
        console.log('success', res);

        console.log('file://' + downloaddest)

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

  }

将文本写入本地 txt

 /*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。