React Native save base64 image to Album

Remove data:image/png;base64, in your base64 string

var Base64Code = base64Image.split("data:image/png;base64,"); //base64Image is my image base64 string

const dirs = RNFetchBlob.fs.dirs;

var path = dirs.DCIMDir + "/image.png";

RNFetchBlob.fs.writeFile(path, Base64Code[1], 'base64')
.then((res) => {console.log("File : ", res)});

And then I solved my problem.

I solve the problem,
turn out I forgot data:image/png;base64, at beginning of the string.

I remove it with following code

  // json.qr is base64 string
  var image_data = json.qr.split('data:image/png;base64,');
  image_data = image_data[1];

and then save the image file

  import fetch_blob from 'react-native-fetch-blob';
  import RNFS from 'react-native-fs';

  const fs = fetch_blob.fs
  const dirs = fetch_blob.fs.dirs      
  const file_path = dirs.DCIMDir + "/bigjpg.png"

  // json.qr is base64 string "data:image/png;base64,..."

  var image_data = json.qr.split('data:image/png;base64,');
  image_data = image_data[1];

  RNFS.writeFile(file_path, image_data, 'base64')
  .catch((error) => {
    alert(JSON.stringify(error));
  });

I wrote a blog about this

http://1c7.me/react-native-save-base64-image-to-album/