如何在React Native cli中扫描二维码？

Question

是否有人有如何在 React Native cli 中读取二维码的教程或代码，并且可以在当前的 React Native 版本中实际工作？我尝试了很多教程和文档，但没有任何效果。如果它能在 tsx 运行就好了。

Answer 1

使用React Native中的react-native-qrcode-scanner包来扫描二维码。以下是如何使用它的说明：

import QRCodeScanner from 'react-native-qrcode-scanner';

const MyQRCodeScanner = () => {
  const onSuccess = (e) => {
    console.log(e.data);
    // e.data contains the QR code data
  };

  return (
    <QRCodeScanner onRead={onSuccess} />
  );
};

Answer 2

最好的解决方案是使用https://github.com/mrousavy/react-native-vision-camera，因为它基于ML Kit为该相机使用JSI和帧处理器 https://github.com/rodgomesc/vision-camera-code-scanner

import * as React from 'react';

import { StyleSheet, Text } from 'react-native';
import { Camera, useCameraDevices } from 'react-native-vision-camera';
import { useScanBarcodes, BarcodeFormat } from 'vision-camera-code-scanner';

export default function App() {
  const [hasPermission, setHasPermission] = React.useState(false);
  const devices = useCameraDevices();
  const device = devices.back;

  const [frameProcessor, barcodes] = useScanBarcodes([BarcodeFormat.QR_CODE], {
    checkInverted: true,
  });

  // Alternatively you can use the underlying function:
  //
  // const frameProcessor = useFrameProcessor((frame) => {
  //   'worklet';
  //   const detectedBarcodes = scanBarcodes(frame, [BarcodeFormat.QR_CODE], { checkInverted: true });
  //   runOnJS(setBarcodes)(detectedBarcodes);
  // }, []);

  React.useEffect(() => {
    (async () => {
      const status = await Camera.requestCameraPermission();
      setHasPermission(status === 'authorized');
    })();
  }, []);

  return (
    device != null &&
    hasPermission && (
      <>
        <Camera
          style={StyleSheet.absoluteFill}
          device={device}
          isActive={true}
          frameProcessor={frameProcessor}
          frameProcessorFps={5}
        />
        {barcodes.map((barcode, idx) => (
          <Text key={idx} style={styles.barcodeTextURL}>
            {barcode.displayValue}
          </Text>
        ))}
      </>
    )
  );
}

const styles = StyleSheet.create({
  barcodeTextURL: {
    fontSize: 20,
    color: 'white',
    fontWeight: 'bold',
  },
});

Answer 3

您可以使用两个库进行二维码扫描 然后添加所有权限

react-native-qrcode-scanner 
react-native-camera

代码：

const [barcode, setBarcode] = useState(null);


<View style={styles.screen}>
        <View style={styles.caption}>
          <Text style={styles.captionTitleText}>QR Code</Text>
        </View>

        {barcode ? (
          <View style={{alignContent: 'center', alignItems: 'center'}}>
            <TouchableOpacity
              style={{
                backgroundColor: 'navy',
                borderRadius: 10,
                paddingHorizontal: 15,
              }}
              onPress={() =>
                navigation.navigate('Your next screen')
              }>
              <Text style={styles.rmCameraResultText2}>
                Scan Successfully. Tap to fill the Audit.
              </Text>
            </TouchableOpacity>
          </View>
        ) : (
          <RNCamera style={styles.rnCamera} onBarCodeRead={setBarcode} />
        )}

        <View style={styles.cameraControl}>
          <TouchableOpacity style={styles.btn} onPress={() => setBarcode(null)}>
            <Text style={styles.btnText}>New QR Scan</Text>
          </TouchableOpacity>
        </View>
      </View>


const styles = StyleSheet.create({
  screen: {
    flex: 1,
    backgroundColor: '#F2F2FC',
  },
  saveArea: {
    backgroundColor: '#62d1bc',
  },
  topBar: {
    height: 50,
    backgroundColor: '#62d1bc',
    alignItems: 'center',
    justifyContent: 'center',
  },
  topBarTitleText: {
    color: '#ffffff',
    fontSize: 20,
  },
  caption: {
    height: 120,
    justifyContent: 'center',
    alignItems: 'center',
  },
  captionTitleText: {
    color: '#121B0D',
    fontSize: 16,
    fontWeight: '600',
  },
  btn: {
    width: 240,
    borderRadius: 4,
    backgroundColor: '#326A81',
    paddingHorizontal: 20,
    paddingVertical: 10,
    marginVertical: 8,
  },
  btnText: {
    fontSize: 18,
    color: '#ffffff',
    textAlign: 'center',
  },
  rnCamera: {
    flex: 1,
    width: '94%',
    alignSelf: 'center',
  },
  rmCameraResult: {
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#eeeeee',
  },

  rmCameraResultText: {
    fontSize: 15,
    color: '#326A81',
  },
  rmCameraResultText2: {
    fontSize: 20,
    color: 'white',
  },
  cameraControl: {
    height: 180,
    justifyContent: 'center',
    alignItems: 'center',
  },

Answer 4

一种方法是使用 vision-camera-dynamsoft-barcode-reader。

1. 使用react-native-vision-camera进行实时扫描（用作其帧处理器）。

   import { decode } from 'vision-camera-dynamsoft-barcode-reader';
   
   const frameProcessor = useFrameProcessor((frame) => {
     'worklet';
     const barcodes = decode(frame);
   }, []);
   

2. 从 Base64 编码的静态图像中读取条形码。

   let results = await decodeBase64(base64);