某个页面禁用物理返回键

1、引入组件
import{
BackHandler,
}from’react-native’;
2、增加监听
componentDidMount():void{
BackHandler.addEventListener(‘hardwareBackPress’,this.onBackButtonPressAndroid);
}
3、监听方法
onBackButtonPressAndroid=()=>{if(this.props.navigation.isFocused()){if(this.lastBackPressed&&this.lastBackPressed+2000>=Date.now()){//最近2秒内按过back键，能够退出使用。returnfalse;
}this.lastBackPressed=Date.now();
ToastAndroid.show(‘再按一次退出使用’,ToastAndroid.SHORT);returntrue;
}
}
4、删除监听
componentWillUnmount():void{
BackHandler.removeEventListener(‘hardwareBackPress’,this.onBackButtonPressAndroid);
}