Javascript 将地图视图调整为带有挂钩的本地地图,函数
所以我有mapview:Javascript 将地图视图调整为带有挂钩的本地地图,函数,javascript,react-native,google-maps,google-maps-markers,react-native-maps,Javascript,React Native,Google Maps,Google Maps Markers,React Native Maps,所以我有mapview: import * as React from 'react'; import { StyleSheet, View, Text, ScrollView, Animated, Dimensions, Image, } from "react-native"; import MapView, {Callout, Marker, PROVIDER_GOOGLE} from "react-na
import * as React from 'react';
import {
StyleSheet,
View,
Text,
ScrollView,
Animated,
Dimensions,
Image,
} from "react-native";
import MapView, {Callout, Marker, PROVIDER_GOOGLE} from "react-native-maps";
import * as Location from 'expo-location';
QueryResult from '../../assets/Data.json'; //JSON FILE in desc
import {AppLoading} from "expo";
const styles = StyleSheet.create({
page: {
flex: 1,
justifyContent: "center",
alignItems: "center",
backgroundColor: "#F5FCFF"
},
container: {
flex:1,
backgroundColor: "tomato"
},
map: {
flex: 1
},
bubble:{
backgroundColor: Colors.WHITE1,
borderRadius: 20,
flexDirection: "column",
},
name:{
},
icon:{
width: 30,
height:30,
},
});
const { width, height } = Dimensions.get("window");
function GoogleMapItem() {
const initialRegion = {
latitude: 53.3661,
longitude: 14.5943,
}
const navigation = useNavigation();
const [location, setLocation] = React.useState(initialRegion);
const [errorMsg, setErrorMsg] = React.useState(null);
const mapRef = React.useRef()
const [QueryResult, SetQueryResult] = React.useState(null);
let iz ={
latDelta: 0.015,
longDelta: 0.08,
}
let ZOOMS = {
_latitudeDeltaZOOM_OUT1 : iz.latDelta,
_longitudeDeltaZOOM_OUT1: iz.longDelta,
_latitudeDeltaZOOM_INITIAL : iz.latDelta*0.2,
_longitudeDeltaZOOM_INITIAL: iz.longDelta*0.2,
_latitudeDeltaZOOM_IN1 : iz.latDelta*0.1,
_longitudeDeltaZOOM_IN1: iz.longDelta*0.1,
}
React.useEffect(() => {
(async () => {
let { status } = await Location.requestPermissionsAsync();
if (status !== 'granted') {
setErrorMsg('Permission to access location was denied');
}
let location = await Location.getCurrentPositionAsync({});
const {longitude, latitude} = location.coords
setLocation({
...location,
longitude: longitude,
latitude: latitude,
})
})();
}, []);
return(
<View style={styles.map}>
<MapView style={styles.map}
provider={PROVIDER_GOOGLE}
loadingEnabled={true}
region={{
latitude: location.latitude,
longitude: location.longitude,
latitudeDelta: ZOOMS._latitudeDeltaZOOM_OUT1,
longitudeDelta: ZOOMS._latitudeDeltaZOOM_OUT1,
}}
showsUserLocation
followsUserLocation
userLocationUpdateInterval
ref={mapRef}
>
{QueryResult.results.map((element,index)=>
<Marker key={index} identifier={element.place_id} coordinate={{
latitude: element.geometry.location.lat,
longitude: element.geometry.location.lng,
}}
>
<View>
<Image source={{uri: element.icon}} style={{width:25,height:25,}}></Image>
</View>
</Marker>
)}
</MapView>
</View>
)
}
export default React.memo(GoogleMapItem)
此视图正在从查询中呈现标记(包含餐厅或其他对象的视图)
我想调整mapview以查看所有可能的标记
用钩子可以吗?(几乎所有互联网解决方案都使用:
{mapRef=>this.mapRef=mapRef}
所以它需要类组件
尝试了不同的方法,例如:
OnMapReady or onLayout={ mapRef.current.fitToSuppliedMarkers(markerArray)}
OnMapReady or onLayout={ mapRef.current.fitToElements(true)}
将所有标记Lat、Lng添加到阵列中,然后:
OnMapReady or onLayout={ mapRef.current.fitToCoordinates(markerArrayLatLng}
在useEffect中也尝试了使用这些方法,但根本看不到mapRef(mapRef未定义)
但是什么也没有发生,我认为错误在于,在第一次初始渲染时,这些方法没有看到ref to map。
因为当我使用按钮调用方法时,它工作得很好
<Button title={"test"} onPress={mapRef.current.fitToElements(true)}/>
这在带有钩子的函数中是可能的,还是我需要将整个函数重新设置为类组件?
抱歉,我的语言出现了错误。followUserLocation正在自动缩放到用户位置(速度太快),FittoElement和其他元素无法工作(它们可以工作,但会立即缩放)。 所以我在下面设置了超时
<Button title={"test"} onPress={mapRef.current.fitToElements(true)}/>