BarCodeScanner can't scan

when i use BarCodeScanner ,the camera work ,but can’t scan info from qrcode.(ios can scan,android can’t) ,what happend?
my phone is Mi 5X

package.json and app.js as follow:

  "name": "ex1",
  "version": "0.1.0",
  "private": true,
  "devDependencies": {
    "react-native-scripts": "1.13.2",
    "jest-expo": "26.0.0",
    "react-test-renderer": "16.3.0-alpha.1"
  "main": "./node_modules/react-native-scripts/build/bin/crna-entry.js",
  "scripts": {
    "start": "react-native-scripts start",
    "eject": "react-native-scripts eject",
    "android": "react-native-scripts android",
    "ios": "react-native-scripts ios",
    "test": "jest"
  "jest": {
    "preset": "jest-expo"
  "dependencies": {
    "expo": "26.0.0",
    "react": "16.3.0",
    "react-native": ""
export default class BarcodeScannerExample extends React.Component {
  state = {
    hasCameraPermission: null,

  async componentWillMount() {
    const { status } = await Permissions.askAsync(Permissions.CAMERA);
    this.setState({hasCameraPermission: status === 'granted'});

  render() {
    const { hasCameraPermission } = this.state;

    if (hasCameraPermission === null) {
      return <Text>Requesting for camera permission</Text>;
    } else if (hasCameraPermission === false) {
      return <Text>No access to camera</Text>;
    } else {
      return (
        <View style={{ flex: 1 }}>

  _handleBarCodeRead = ({ type, data }) => {
    alert('Bar code with type ${type} and data ${data} has been scanned!');

Hey @songsong2. What QR code are you trying to scan? The BarCodeScanner is working on SDK 26 for me.

I try to scan a url and a string,but i can’t get the result. my sdk version is 26.

I have the same problem.

  • iPhones work well
  • Most Androids work well
  • Samsung A3, Android 7.0 will not trigger any code recognition
    • Neither Expo Client nor standalone APK’s trigger any recognition
    • However, the same phone does scan QR’s with other apps

Is anyone having the same problem?
Thank you

Sorry,I did not visit this site recently.
Android 7.1.2 will not trigger any code recognition.I solve the problem with using sdk22.
Thank you.

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