How to download a file with React Native?

问题

I am building an app with React Native, for Android and iOS. I am trying to let the user download a PDF file when clicking on a button.

react-native-file-download does not support Android
react-native-fs does nothing when I trigger downloadFile (nothing shows up on the notification bar), and I am not able to find the file after that. I added android.permission.WRITE_EXTERNAL_STORAGE to the Android Manifest file. I double-checked that the file I am trying to download exists (when it does not, the library throws an error)

I do not find other solutions for this problem. I have found libraries for viewing a PDF, but I would like to let the user download the PDF.

回答1:

Just implemented the download feature an hour ago :p

Follow these steps:

a) npm install rn-fetch-blob

b) follow the installation instructions.

b2) if you want to manually install the package without using rnpm, go to their wiki.

c) Finally, that's how I made it possible to download files within my app:

const { config, fs } = RNFetchBlob
let PictureDir = fs.dirs.PictureDir // this is the pictures directory. You can check the available directories in the wiki.
let options = {
  fileCache: true,
  addAndroidDownloads : {
    useDownloadManager : true, // setting it to true will use the device's native download manager and will be shown in the notification bar.
    notification : false,
    path:  PictureDir + "/me_"+Math.floor(date.getTime() + date.getSeconds() / 2), // this is the path where your downloaded file will live in
    description : 'Downloading image.'
  }
}
config(options).fetch('GET', "http://www.example.com/example.pdf").then((res) => {
  // do some magic here
})

回答2:

If you're using Expo, react-native-fetch-blob won't work. Use FileSystem.

Here's a working example:

const { uri: localUri } = await FileSystem.downloadAsync(remoteUri, FileSystem.documentDirectory + 'name.ext');

Now you have localUri with the path to the downloaded file. Feel free to set your own filename instead of name.ext.

来源：https://stackoverflow.com/questions/44546199/how-to-download-a-file-with-react-native

标签

react-native

react-native-fs