如何从react原生javascript语法切换到es6

如何从react原生javascript语法切换到es6,javascript,reactjs,ecmascript-6,react-native,Javascript,Reactjs,Ecmascript 6,React Native,我正在将一些代码改写为es6语法,但遇到了问题。这是我的第一个react本地项目,所以我对一些事情不熟悉。我从这个演示开始 我添加了带有登录屏幕的导航。当我登录并切换视图时,我在 onLayout() { var me = this, gmap = this.refs.gmap; this.refs.workspace.measure(function(ox, oy, width, height, px, py) { me.setState({ mapHeight: heig

我正在将一些代码改写为es6语法,但遇到了问题。这是我的第一个react本地项目,所以我对一些事情不熟悉。我从这个演示开始 我添加了带有登录屏幕的导航。当我登录并切换视图时,我在

 onLayout() {
var me = this,
  gmap = this.refs.gmap;

this.refs.workspace.measure(function(ox, oy, width, height, px, py) {
  me.setState({
    mapHeight: height,
    mapWidth: width
  });
 });
}
undefined不是对象(正在计算'this.refs')

这是整个文件。如果你需要更多的信息,让我知道!谢谢

Map.js

    class Map extends Component {
  constructor(props) {
    super(props)
    this.state = {
      locationIcon: require("image!green_circle"),
      currentLocation: undefined,
      locationManager: undefined,
      enabled: false,
      isMoving: false,
      odometer: 0,
      paceButtonStyle: commonStyles.disabledButton,
      paceButtonIcon: 'play',
      navigateButtonIcon: 'navigate',
      mapHeight: 300,
      mapWidth: 300,
      // mapbox
      center: {
        lat: 40.7223,
        lng: -73.9878
      },
      zoom: 10,
      markers: []
    }
  }

  componentDidMount() {

    var me = this,
      gmap = this.refs.gmap;

    this.locationManager = this.props.locationManager;

    // location event
    this.locationManager.on("location", function(location) {
      console.log('- location: ', JSON.stringify(location));
      me.setCenter(location);
      gmap.addMarker(me._createMarker(location));

      me.setState({
        odometer: (location.odometer / 1000).toFixed(1)
      });

      // Add a point to our tracking polyline
      if (me.polyline) {
        me.polyline.addPoint(location.coords.latitude, location.coords.longitude);
      }
    });
    // http event
    this.locationManager.on("http", function(response) {
      console.log('- http ' + response.status);
      console.log(response.responseText);
    });
    // geofence event
    this.locationManager.on("geofence", function(geofence) {
      console.log('- onGeofence: ', JSON.stringify(geofence));
    });
    // error event
    this.locationManager.on("error", function(error) {
      console.log('- ERROR: ', JSON.stringify(error));
    });
    // motionchange event
    this.locationManager.on("motionchange", function(event) {
      console.log("- motionchange", JSON.stringify(event));
      me.updatePaceButtonStyle();
    });

    // getGeofences
    this.locationManager.getGeofences(function(rs) {
      console.log('- getGeofences: ', JSON.stringify(rs));
    }, function(error) {
      console.log("- getGeofences ERROR", error);
    });

    SettingsService.getValues(function(values) {
      values.license = "eddbe81bbd86fa030ea466198e778ac78229454c31100295dae4bfc5c4d0f7e2";
      values.orderId = 1;
      values.stopTimeout = 0;
      //values.url = 'http://192.168.11.120:8080/locations';

      me.locationManager.configure(values, function(state) {
        console.log('- configure state: ', state);
        me.setState({
          enabled: state.enabled
        });
        if (state.enabled) {
          me.initializePolyline();
          me.updatePaceButtonStyle()
        }
      });
    });

    this.setState({
      enabled: false,
      isMoving: false
    });
  }
  _createMarker(location) {
    return {
      title: location.timestamp,
      id: location.uuid,
      icon: this.locationIcon,
      anchor: [0.5, 0.5],
      coordinates: {
        lat: location.coords.latitude,
        lng: location.coords.longitude
      }
    };
  }

  initializePolyline() {
    // Create our tracking Polyline
    var me = this;
    Polyline.create({
      points: [],
      geodesic: true,
      color: '#2677FF',
      width: 12
    }, function(polyline) {
      me.polyline = polyline;
    });
  }

  onClickMenu() {
    this.props.drawer.open();
  }

  onClickEnable() {
    var me = this;
    if (!this.state.enabled) {
      this.locationManager.start(function() {
        me.initializePolyline();
      });
    } else {
      this.locationManager.resetOdometer();
      this.locationManager.stop();
      this.setState({
        markers: [{}],
        odometer: 0
      });
      this.setState({
        markers: []
      });
      if (this.polyline) {
        this.polyline.remove(function(result) {
          me.polyline = undefined;
        });
      }
    }

    this.setState({
      enabled: !this.state.enabled
    });
    this.updatePaceButtonStyle();
  }

  onClickPace() {
    if (!this.state.enabled) {
      return;
    }
    var isMoving = !this.state.isMoving;
    this.locationManager.changePace(isMoving);

    this.setState({
      isMoving: isMoving
    });
    this.updatePaceButtonStyle();
  }

  onClickLocate() {
    var me = this;

    this.locationManager.getCurrentPosition({
      timeout: 30
    }, function(location) {
      me.setCenter(location);
      console.log('- current position: ', JSON.stringify(location));
    }, function(error) {
      console.error('ERROR: getCurrentPosition', error);
      me.setState({
        navigateButtonIcon: 'navigate'
      });
    });
  }

  onRegionChange() {
    console.log('onRegionChange');
  }

  setCenter(location) {
    this.setState({
      navigateButtonIcon: 'navigate',
      center: {
        lat: location.coords.latitude,
        lng: location.coords.longitude
      },
      zoom: 16
    });
  }

  onLayout() {
    var me = this,
      gmap = this.refs.gmap;

    this.refs.workspace.measure(function(ox, oy, width, height, px, py) {
      me.setState({
        mapHeight: height,
        mapWidth: width
      });
    });
  }

  updatePaceButtonStyle() {
    var style = commonStyles.disabledButton;
    if (this.state.enabled) {
      style = (this.state.isMoving) ? commonStyles.redButton : commonStyles.greenButton;
    }
    this.setState({
      paceButtonStyle: style,
      paceButtonIcon: (this.state.enabled && this.state.isMoving) ? 'pause' : 'play'
    });
  }

  render() {
    return (
      <View style={commonStyles.container}>
        <View style={commonStyles.topToolbar}>
          <Icon.Button name="android-options" onPress={this.onClickMenu} backgroundColor="transparent" size={30} color="#000" style={styles.btnMenu} underlayColor={"transparent"} />
          <Text style={commonStyles.toolbarTitle}>Background Geolocation</Text>
          <SwitchAndroid onValueChange={this.onClickEnable} value={this.state.enabled} />
        </View>
        <View ref="workspace" style={styles.workspace} onLayout={this.onLayout}>
          <RNGMap
            ref={'gmap'}
            style={{width: this.state.mapWidth, height: this.state.mapHeight}}
            markers={this.state.markers}
            zoomLevel={this.state.zoom}
            onMapChange={(e) => console.log(e)}
            onMapError={(e) => console.log('Map error --> ', e)}
            center={this.state.center} />

        </View>
        <View style={commonStyles.bottomToolbar}>
          <Icon.Button name={this.state.navigateButtonIcon} onPress={this.onClickLocate} size={25} color="#000" underlayColor="#ccc" backgroundColor="transparent" style={styles.btnNavigate} />
          <Text style={{fontWeight: 'bold', fontSize: 18, flex: 1, textAlign: 'center'}}>{this.state.odometer} km</Text>
          <Icon.Button name={this.state.paceButtonIcon} onPress={this.onClickPace} iconStyle={commonStyles.iconButton} style={this.state.paceButtonStyle}><Text>State</Text></Icon.Button>
          <Text>&nbsp;</Text>
        </View>
      </View>
    );
  }
};

module.exports = Map;
类映射扩展组件{
建造师(道具){
超级(道具)
此.state={
位置图标:需要(“图像!绿色圆圈”),
当前位置:未定义,
locationManager:未定义,
启用:false,
伊斯莫温:错,
里程表:0,
paceButtonStyle:commonStyles.disabledButton,
尼康:“玩”,
导航按钮:“导航”,
地图高度:300,
地图宽度:300,
//地图盒
中心:{
纬度:40.7223,
液化天然气:-73.9878
},
缩放:10,
标记:[]
}
}
componentDidMount(){
var me=这个,
gmap=this.refs.gmap;
this.locationManager=this.props.locationManager;
//位置事件
此.locationManager.on(“位置”),函数(位置){
log('-location:',JSON.stringify(location));
me.setCenter(位置);
gmap.addMarker(me._createMarker(位置));
我是塞斯塔({
里程表:(位置.里程表/1000).toFixed(1)
});
//将点添加到跟踪多段线
if(me.多段线){
me.polyline.addPoint(location.coords.lation,location.coords.longitude);
}
});
//http事件
this.locationManager.on(“http”,函数(响应){
log('-http'+response.status);
console.log(response.responseText);
});
//地球围栏活动
此.locationManager.on(“地理围栏”,功能(地理围栏){
log('-onGeofence:',JSON.stringify(geoffence));
});
//错误事件
this.locationManager.on(“错误”,函数(错误){
log('-ERROR:',JSON.stringify(ERROR));
});
//运动变化事件
this.locationManager.on(“motionchange”,函数(事件){
log(“-motionchange”,JSON.stringify(event));
me.updatePaceButtonStyle();
});
//围篱
this.locationManager.getGeofences(函数(rs){
log('-getgeofenses:',JSON.stringify(rs));
},函数(错误){
log(“-getgeofenses ERROR”,ERROR);
});
SettingsService.getValues(函数(值){
values.license=“EDDB81BBD86FA030EA466198E778AC7822945C31100295DAE4BFC5C4D0F7E2”;
values.orderId=1;
values.stopTimeout=0;
//values.url=http://192.168.11.120:8080/locations';
me.locationManager.configure(值、函数(状态){
log('-configure state:',state);
我是塞斯塔({
已启用:state.enabled
});
如果(state.enabled){
me.initializePolyline();
me.updatePaceButtonStyle()
}
});
});
这是我的国家({
启用:false,
伊斯莫温:错
});
}
_createMarker(位置){
返回{
标题:location.timestamp,
id:location.uuid,
图标:this.locationIcon,
锚定:[0.5,0.5],
坐标:{
纬度:位置坐标纬度,
液化天然气:位置.坐标.经度
}
};
}
initializePolyline(){
//创建跟踪多段线
var me=这个;
Polyline.create({
要点:[],
测地线:正确,
颜色:“#2677FF”,
宽度:12
},函数(多段线){
me.polyline=多段线;
});
}
onClickMenu(){
this.props.drawer.open();
}
onClickEnable(){
var me=这个;
如果(!this.state.enabled){
this.locationManager.start(函数(){
me.initializePolyline();
});
}否则{
此.locationManager.reset里程表();
this.locationManager.stop();
这是我的国家({
标记:[{}],
里程表:0
});
这是我的国家({
标记:[]
});
if(此.多段线){
此.polyline.remove(函数(结果){
me.polyline=未定义;
});
}
}
这是我的国家({
已启用:!this.state.enabled
});
this.updatePaceButtonStyle();
}
onclickspace(){
如果(!this.state.enabled){
返回;
}
var isMoving=!this.state.isMoving;
this.locationManager.changePace(isMoving);
这是我的国家({
isMoving:isMoving
});
this.updatePaceButtonStyle();
}
onClickLocate(){
var me=这个;
this.locationManager.getCurrentPosition({
超时时间:30
},功能(位置){
me.setCenter(位置);
log('-current position:',JSON.stringify(location));
},函数(错误){
console.error('error:getCurrentPosition',error);
我是塞斯塔({
导航按钮:“导航”
});
});
}
onRegionChange(){
log('onRegionChange');
}
设置中心(位置){
这是我的国家({
导航按钮:“导航”,
中心:{
纬度:位置坐标纬度,
液化天然气:位置.坐标.经度
},
缩放:16
});
}
网上购物{
var me=这个,
gmap=this.refs.gmap;
此.refs.workspace.measure(函数(ox、oy、宽度、高度、px、py){
我是塞斯塔({
地图高度:高度,
mapWidth:width
});
});
}
updatePaceButtonStyle(){
var style=commonStyles.disabledButton;
if(this.state.enabled){
style=(this.state.isMoving)?commonStyles.redButton:commonStyles.greenButton;
}
这是我的国家({
paceButtonStyle:样式,
paceButtonIcon:(this.state.enabled&&this.state.isMoving)?“暂停”:“播放”
});
}
render(){
返回(
背景地理定位
console.log(e)}
<View ref="workspace" style={styles.workspace} onLayout={this.onLayout.bind(this)}>
onLayout = () => {
...
};