react-native-maps fitToSuppliedMarker/fitToCorodinates不会显示所有标记

Question

我正在尝试使用简单的MapView和显示2个标记。

它们都正确地显示在地图视图上，但同时在屏幕上不可见(默认情况下渲染为Image1)

我必须执行手动拖动操作，才能在屏幕上看到这两个标记。(手动拖动地图后执行Image2，以便在屏幕上可以看到它们)

我尝试使用fitToSuppliedMarkers/ but，但似乎都不起作用。

export default class FavItemMapView extends Component{

constructor(props){
    super(props)
    this.state={
        position:{
            latitude:1.286353,
            longitude:103.853067,
            latitudeDelta: 0,
            longitudeDelta: 0,
        },
        error:null
    }
    this.mapRef = null;
}

componentWillMount(){

    const favPlaceLatitude = parseFloat(this.props.navigation.state.params.latitude)
    const favPlaceLongitude = parseFloat(this.props.navigation.state.params.longitude)
    markers.push({latitude:favPlaceLatitude,longitude:favPlaceLongitude});
    navigator.geolocation.getCurrentPosition(
        (position) => {
          console.log("wokeeey" + width + height);
          console.log(position);
          var lat = parseFloat(position.coords.latitude)
          var long = parseFloat(position.coords.longitude)

          var initialRegion = {
            latitude: lat,
            longitude: long,
            latitudeDelta: LATITUDE_DELTA,
            longitudeDelta: LONGITUDE_DELTA,
          }

          this.onRegionChange(initialRegion)
        },
        (error) => this.setState({ error: error.message }),
        { enableHighAccuracy: false, timeout: 200000, maximumAge: 1000 },
      );
}

onRegionChange(region) {
    this.setState({ position:region })
}

componentDidMount(){
    //this.mapRef.fitToSuppliedMarkers(markerIDs,true);
    const favPlaceLatitude = parseFloat(this.props.navigation.state.params.latitude)
    const favPlaceLongitude = parseFloat(this.props.navigation.state.params.longitude)
    this.mapRef.fitToCoordinates([{latitude:favPlaceLatitude,longitude:favPlaceLongitude}], {
        edgePadding: {
          bottom: 200, right: 50, top: 150, left: 50,
        },
        animated: true,
    });
}

render(){

    const { navigation } = this.props;
    const favPlaceLatitude = parseFloat(navigation.state.params.latitude)
    const favPlaceLongitude = parseFloat(navigation.state.params.longitude)

    return(
        <View style={styles.container}>
            <MapView provider={MapView.PROVIDER_GOOGLE} ref={ref => {this.mapRef = ref;}} style={styles.map} region={this.state.position}>
                {this.state.position.latitude &&
                    <MapView.Marker identifier="Marker2" coordinate={{latitude:this.state.position.latitude,longitude:this.state.position.longitude}} pinColor="red"/>
                }
                {this.state.position.longitude &&
                    <MapView.Marker identifier="Marker1" coordinate={{latitude:favPlaceLatitude,longitude:favPlaceLongitude}} pinColor="green"/>
                }
            </MapView>
        </View>
    );
  }
}

const styles={
  container:{
    ...StyleSheet.absoluteFillObject,
    justifyContent: 'flex-end',
    alignItems: 'center',
  },
  map:{
    padding:100,
    ...StyleSheet.absoluteFillObject
  }
}

你能告诉我哪里出了问题吗？附加模拟器图像以供参考。

​

Answer 1

<MapView
    provider={MapView.PROVIDER_GOOGLE}
    ref={map => {this.map = map}}
    style={{ flex: 1 }}
    initialRegion={{latitude:this.state.request.latitude,
      longitude:this.state.request.longitude,
      latitudeDelta: 0.0922,
      longitudeDelta: 0.0421,}}
    onMapReady={() => {this.map.fitToSuppliedMarkers(['mk1','mk2'],{ edgePadding: 
      {top: 50,
        right: 50,
        bottom: 50,
        left: 50}

    })}}
    >
    <Marker
    image={require('../../../assets/pin.png')}
    coordinate={{latitude:this.state.request.latitude,longitude:this.state.request.longitude}} 
    title='Punto de partida'
    identifier={'mk1'}
    >

    </Marker>

    <Marker
    image={require('../../../assets/pin_final.png')}
    coordinate={{latitude:this.state.request.latitude_destinity,longitude:this.state.request.longitude_destinity}} 
    title='Punto de destino'
    identifier={'mk2'}
>

Answer 2

因此，从我使用这个库的经验来看，我发现最好的体验是在MapView组件上使用onMapReady属性。

https://github.com/react-native-community/react-native-maps/blob/master/docs/mapview.md#events

<MapView
  ...
  onMapReady{() => {
    this.mapRef.fitToCoordinates(...)
  }}
/>

或

<MapView
  ...
  onMapReady{() => {
    this.mapRef.fitToSuppliedMarkers(...)
  }}
/>

让我知道这是否有帮助，我仍在学习它，但这种方法假设您已经准备好要传递到Map组件中渲染的标记。

Answer 3

在我看来，最好的方法是在iOS中使用fitToElements，在安卓中使用fitToSuppliedMarkers (或fitToCoordinates)。我得到的代码最终是这样的：

import React, { useRef, useCallback } from 'react';
import { Platform } from 'react-native';
import MapView, { PROVIDER_GOOGLE, LatLng, Marker } from 'react-native-maps';

type Props = {
  origin: LatLng;
  destination: LatLng;
}

export default function ({ origin, destination }: Props) {
    const ref = useRef<MapView>(null);

    // effects
    const onMapReadyHandler = useCallback(() => {
      if (Platform.OS === 'ios') {
        ref?.current?.fitToElements(false);
      } else {
        ref?.current?.fitToCoordinates([origin, destination], {
          animated: true,
          edgePadding: {
            top: 150,
            right: 50,
            bottom: 50,
            left: 50,
          },
        });
      }
    }, [ref]);

    // UI
    return (
      <MapView
        style={{ width: '100%', height: '100%' }}
        ref={ref}
        provider={PROVIDER_GOOGLE}
        onMapReady={onMapReadyHandler}
      >
        <Marker coordinate={origin} identifier="origin" />
        <Marker coordinate={destination} identifier="destination" />
      </MapView>
    );
  }
);