React-Native 的BackAndroid

BackHandler or BackAndroid

BackAndroid 已经废弃

这个只有三个static 方法

    static exitApp()     static addEventListener(eventName, handler)     static removeEventListener(eventName, handler)

使用说明

Navigator.initialRoute配置的Component

因为在Navigator配置页面中 this.props.navigator is undefined is not an object 不知道为啥这样????
解决方法

在第一个 页面 中设置 如下

    _onBackEvent() {        const navigator = this.props.navigator;        let count = navigator.getCurrentRoutes();        if (count.length > 1) {            navigator.pop();            return true;        } else {            let timestamp = (new Date()).valueOf();            if (timestamp - firstClick > 2000) {                firstClick = timestamp;                ToastAndroid.show('再按一次退出', ToastAndroid.SHORT);                return true;            }        }        return false;    }    <!--添加到constructor 中this.onBackEvent=this._onBackEvent.bind(this)-->    componentWillMount() {        BackHandler.addEventListener("hardwareBackPress", this.onBackEvent);    }    componentWillUnmount() {        BackHandler.removeEventListener("hardwareBackPress", this.onBackEvent);    }

<span id="jump">解决不能在<Navigator Component />中设置返回和 this.props.navigator is undefined is not an object 错误

</span>

     <Navigaor  ref={component => this.navigator = component}        ...     />     <!--加入 ref={component => this.navigator = component}-->

在_onBackEvent 使用 的this.props.navigator 换成 this.navigator 问题就解决了