react-native: JavaScript not work in webview

When I use the webview in my project，JavaScript not work in the HTML file，Here my code: `` `

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

    export default class NoteEditor extends Component {
      render() {
        return (
          <WebView 
            style={styles.container} 
            source={require('./editor.html')}
            injectedJavaScript={'function myfunc() { alert(123) };myfunc();'}
            javaScriptEnabled={true}
            startInLoadingState={true}
          />

        );
      }
    };

    const styles = StyleSheet.create({
      container: {
        flex: 1,
      },
    });

`

-I use RN 0.29.2 -in RN 0.27 is ok what should I do? thanks