React Native TypeError：无法读取未定义的属性“createClient”

Question

我是 React 本机框架的新手。我使用“create-react-native-app AwesomeProject”创建了应用程序。我想在我的项目中使用 BLE，因此我安装了“react-native-ble-plx”模块，但是当我创建 BleManager 实例时，它会抛出错误 TypeError: Cannot read property 'createClient' of undefined。为什么会抛出这个错误？我的 App.js 是：

import React from "react";
import { StyleSheet, Button, Text, View, Alert } from "react-native";
import { BleManager } from 'react-native-ble-plx';
export default class App extends React.Component {

 constructor() {
    super();
    this.manager = new BleManager();
 }

 TestFunction() {   
    Alert.alert('Button Pressed !!!')   
 }

render() {
  return (
    <View style={styles.container}>
      <Button onPress={ this.TestFunction } title="Learn 
          More"color="#841584" /> 
    </View>
  );
  }
 } 

const styles = StyleSheet.create({
container: {
  flex: 1,
  backgroundColor: "#fff",
  alignItems: "center",
  justifyContent: "center"
}
});

Answer 1

添加this.manager = new BleManager();到 componentDidMount()