undefined is not an object (evaluating 'this.props.navigator.push')

在通过navigator 进行页面跳转的过程中  一直报 这样的错误

先看程序入口文件index.android.js

import React, { Component } from 'react';

import {

  AppRegistry,

  StyleSheet,

  Text,

  TouchableHighlight,  

  Navigator,

} from 'react-native';

import Welcome from './Welcome';

 class MyProject extends Component {

  render() {

       var defaultName = 'Welcome';

     var defaultComponent = Welcome;

    return (

    

    <Navigator

          //指定了默认的页面，也就是启动app之后会看到的第一屏，需要两个参数，name跟component

          initialRoute={{ name: defaultName, component: defaultComponent }}

          configureScene={(route) => {

            //跳转的动画

            return Navigator.SceneConfigs.FadeAndroid;

          }}

          renderScene={(route, navigator) => {

            let Component = route.component;

            if(route.component){

                return <Component {...route.params} navigator={navigator} />

            }

          }} />

    );

  }

}

AppRegistry.registerComponent('MyProject', () => MyProject);

再看 第一个页面 欢迎页面：Welcome.js

import React, { Component } from 'react';

import {

  Text,

  View,

  Navigator,

  TouchableHighlight

} from 'react-native';

import Login from "./Login";

export default class Welcome extends Component {

   

 

  constructor(props){

        super(props);

        this.state = {};

    }

  _onPress(){

       let navigator = this.props.navigator;

        Alert.alert('Button has been pressed!'+navigator);

        if (navigator) {

          navigator.push({

                name:'Login',

                component:Login

        });

        }

    }

  render() {

     return (

            <View>

              <TouchableHighlight  onPress={this._onPress.bind(this)}>   

              <TouchableHighlight  onPress={this._onPress}>   

<Text >此为欢迎页面 点击进入登录页面</Text> </TouchableHighlight> </View> ); }}

红色的代替蓝色的就可以解决此问题了