react native踩坑日记（1）：react-native中集成二维码扫描，识别相册二维码

声明：写这篇文章的时候安卓手机未测试，苹果手机可正常使用，如果有后续结果，会在更新，但是理论上是适配ios和安卓
首先选择如下三个npm包

import {RNCamera} from 'react-native-camera';
import ImagePicker from 'react-native-image-picker';
import {QRreader} from 'react-native-qr-scanner';

安装方法

yarn add react-native-camera
yarn add react-native-image-picker

其中重点说明一下，识别选择相册中的二维码，在百度的过程中有一个npm包出现的次数最多eact-native-local-barcode-recognizer，这个有人使用，你也可以试试。但是我安装的时候出现了点问题报错如下：

无奈解决不掉这个问题，就换成了react-native-qr-scanner，请使用以下两种方式安装，详细地址

yarn add git+https://github.com/ihor-linovitsky/react-native-qr-scanner.git
or 
npm install git+https://github.com/ihor-linovitsky/react-native-qr-scanner.git

具体使用方法可点击详细地址查看。

还遗留一个问题，大佬能够解决的话麻烦在评论里回复一下：

1. 写了个扫描动画，想要实现扫描成功动画就停止。

上面两个正常安装即可，react-native-camera、react-native-image-picker，使用方法去github或者npm官网查阅，附上我的代码。扫描成功的后的结果都会通过alert弹出，没做任何处理，方便自己做其他操作

提示：安装完插件记得 cd ios -> pod install，可能有的不需要，虽然0.6以后不需要手动link，但是还是需要运行，以防万一，RN的报错贼难处理

import React, {Component} from 'react';
import {
  Dimensions,
  StyleSheet,
  View,
  Animated,
  Easing,
  Text,
  Button,
  Alert,
} from 'react-native';
import {RNCamera} from 'react-native-camera';
import ImagePicker from 'react-native-image-picker';
import {QRreader} from 'react-native-qr-scanner';
import {Modal, Provider} from '@ant-design/react-native';

const options = {
  title: '请选择',
  quality: 0.8,
  cancelButtonTitle: '取消',
  takePhotoButtonTitle: null,
  chooseFromLibraryButtonTitle: '选择相册',
  customButtons: [{name: 'hangge', title: '输入编码'}],
  allowsEditing: true,
  noData: false,
  storageOptions: {
    skipBackup: true,
    path: 'images',
  },
};

export default class App extends Component {
  static navigationOptions = ({navigation}) => {
    return {
      title: '扫一扫',
      headerRight: () => (
        
           navigation.state.params.onchangeTorchState()}
          />
           navigation.state.params.choosePicker()}
          />
        
      ),
    };
  };

  //构造函数
  constructor(props) {
    super(props);
    this.state = {
      torchState: 'off',
      qrCode: null,
    };
    this.moveAnim = new Animated.Value(0);
  }

  componentDidMount() {
    this.startAnimation();
    this.props.navigation.setParams({
      choosePicker: this.choosePicker,
      onchangeTorchState: this.onchangeTorchState,
      torchState: this.state.torchState,
    });
  }

  _onBarCodeRead = (value) => {
    const {qrCode} = this.state;
    if (qrCode) {
      return;
    }
    this.setState(
      {
        qrCode: value,
      },
      () => {
        alert(this.state.qrCode.data);   // 打印出扫描后的数据
      },
    );
  };

  // 扫描动画
  startAnimation = () => {
    this.moveAnim.setValue(0);
    Animated.timing(this.moveAnim, {
      toValue: 1,
      duration: 1500,
      easing: Easing.linear,
      useNativeDriver: true,
    }).start(() => this.startAnimation());
  };

  // 修改torchState 状态
  onchangeTorchState = () => {
    const {torchState} = this.state;
    this.setState(
      {
        torchState: torchState === 'off' ? 'ON' : 'off',
      },
      () => {
        this.props.navigation.setParams({torchState: this.state.torchState});
      },
    );
  };

// 从相册获取二维码并扫描返回结果
  choosePicker = () => {
    ImagePicker.showImagePicker(options, (response) => {
      console.log('Response = ', response);
      if (response.didCancel) {
        console.log('User cancelled image picker');
      } else if (response.error) {
        console.log('ImagePicker Error: ', response.error);
      } else if (response.customButton) {
        this.onClickModal();
      } else {
        if (response.uri) {
          var path = response.path;
          if (!path) {
            path = response.uri;
          }
          QRreader(path)
            .then((data) => {
              Alert.alert(data);
            })
            .catch((err) => {
              Alert.alert('识别失败');
            });
        }
      }
    });
  };

  onClickModal = () => {
    Modal.prompt(
      '请输入编码',
      null,
      (code) => console.log(`code: ${code}`),
      'code-password',
      null,
      ['请输入编码'],
    );
  };

  //渲染
  render() {
    const winWidth = Dimensions.get('window').width;
    const winHeight = Dimensions.get('window').height;
    return (
      
        
          
            
              
              
              
                将二维码放入框内，即可自动扫描
              
            
          
        
      
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    flexDirection: 'column',
  },
  preview: {
    flex: 1,
    justifyContent: 'flex-end',
    alignItems: 'center',
  },
  btnText: {color: 'white', fontSize: 16},
  rectangleContainer: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    backgroundColor: 'transparent',
  },
  rectangle: {
    height: 200,
    width: 200,
    borderWidth: 1,
    borderColor: '#00FF00',
    backgroundColor: 'transparent',
  },
  rectangleText: {
    flex: 0,
    color: '#fff',
    marginTop: 10,
  },
  border: {
    flex: 0,
    width: 200,
    height: 2,
    backgroundColor: '#00FF00',
  },
  rightBtn: {
    flex: 1,
    flexDirection: 'row',
    alignItems: 'flex-end',
  },
});