【React Native 實戰】二維碼掃描

1.前言
今天介紹React Native來實現二維碼掃描的功能。首先我們要借助第三方插件react-native-barcode-scanner-universal來實現跨平台二維碼掃描。

2.介紹

react-native-barcode-scanner-universal

react-native-barcode-scanner-universal是react-native-barcodescanner和react-native-camera的結合，react-native-barcodescanner應用於android平台，react-native-camera應用於iOS平台。

3.使用實例

1）安裝：npm install  react-native-barcode-scanner-universal --save

2) 關聯native庫：react-native-barcodescanner 和 react-native-camera

which rnpm || npm install -g rnpm
rnpm link react-native-camera
rnpm link react-native-barcodescanner

3）可以手動關聯，建議用第2步自動關聯。手動關聯參考：

https://github.com/lwansbrough/react-native-camera#manual-install
https://github.com/ideacreation/react-native-barcodescanner#installation

4）關聯成功后，需要修改Android工程下的MainApplication.java代碼

import com.eguma.barcodescanner.BarcodeScannerPackage;//導入

public class MainApplication extends Application implements ReactApplication {
    // (...)

    @Override
    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
        new MainReactPackage(),
        new BarcodeScannerPackage() // add this statement
      );
    }
}

5) react native中使用

import React, { Component } from 'react';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View
} from 'react-native';

import BarcodeScanner from 'react-native-barcode-scanner-universal'

export default class qrcode extends Component {
　//解析數據
  parseData(pdata){
      var ptype = pdata.type;
      var data = pdata.data;

      fetch(data)
          .then((response) => response.json())
          .then((responseJson) => {
              console.log(responseJson);
          })
          .catch((error) => {
              console.error(error);
          });
  }

  render() {
    let scanArea = null
    scanArea = (
        <View style={styles.rectangleContainer}>
          <View style={styles.rectangle} />
        </View>
    )

    return (
      <BarcodeScanner
        onBarCodeRead={  this.parseData.bind(this)  }
        style={styles.camera}
      >
        {scanArea}
      </BarcodeScanner>
    );
  }
}

const styles = StyleSheet.create({
    camera: {
    flex: 1
  },
    rectangleContainer: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    backgroundColor: 'transparent'
  },
    rectangle: {
    height: 250,
    width: 250,
    borderWidth: 2,
    borderColor: '#00FF00',
    backgroundColor: 'transparent'
  }
});

4.效果

掃描成功后打印的數據