为什么要在标记点击事件上重新渲染地图？

Question

我有 google 带有集群的多个标记的地图。单击标记后，我会显示信息 window，但是当我单击标记时，整个地图标记和集群都会重新呈现，这会使页面变慢且烦人。

以下是我的代码：

import React, { Component } from "react";
import axios from "axios";
import { compose, withProps, withHandlers, withStateHandlers } from "recompose";
import {
  withScriptjs,
  withGoogleMap,
  GoogleMap,
  Marker,
  InfoWindow
} from "react-google-maps";
const {
  MarkerClusterer
} = require("react-google-maps/lib/components/addons/MarkerClusterer");

const MapWithAMarkerClusterer = compose(
  withProps({
    googleMapURL:
      "https://maps.googleapis.com/maps/api/js?key=API&v=3.exp&libraries=geometry,drawing,places",
    loadingElement: <div style={{ height: `100%` }} />,
    containerElement: <div style={{ height: `90vh` }} />,
    mapElement: <div style={{ height: `100%` }} />
  }),
  withStateHandlers(
    { InfoWindowobject: null },
    {
      setInfoWindow: () => value => ({ InfoWindowobject: value })
    }
  ),
  withStateHandlers(
    { isOpen: false },
    {
      onToggleOpen: ({ isOpen }) => () => ({
        isOpen: !isOpen
      })
    }
  ),
  withHandlers({
    onMarkerClustererClick: () => markerClusterer => {
      const clickedMarkers = markerClusterer.getMarkers();
    },
    onMarkerClick: props => markerss => {
      const { setInfoWindow, onToggleOpen } = props;

      axios({
        url: "API",
        method: "POST",

      }).then(res => {

        setInfoWindow(res.data);
        onToggleOpen();
      });
    }
  }),
  withScriptjs,
  withGoogleMap
)(props => (
  <GoogleMap
    defaultZoom={5}
    defaultCenter={{ lat: 22.845625996700075, lng: 78.9629 }}
  >
    <MarkerClusterer
      onClick={props.onMarkerClustererClick}
      minimumClusterSize={10}
      averageCenter
      styles={[
        {
          textColor: "white",
          url: imgmapcluster,
          height: 68,
          lineHeight: 3,
          width: 70
        }
      ]}
      enableRetinaIcons
      gridSize={60}
    >
      {props.markers.map((marker, index) => (
        <Marker
          key={index}
          icon={user}
          onClick={props.onMarkerClick.bind(props, marker)}
          position={{ lat: marker.latitude, lng: marker.longitude }}
        />
      ))}
      {props.isOpen && props.InfoWindowobject !== null && (
        <InfoWindow
          position={{
            lat: props.InfoWindowobject.latitude,
            lng: props.InfoWindowobject.longitude
          }}
          onCloseClick={props.onToggleOpen}
        >
          {props.InfoWindowobject !== null && (
            <div className="infobox clearfix" style={{ fontFamily: "Gotham" }}>
              <div className="header clearfix">
                <h3>
                  {props.InfoWindowobject.name},{" "}
                  <small>{props.InfoWindowobject.contactNo}</small>
                </h3>
              </div>

            </div>
          )}
        </InfoWindow>
      )}
    </MarkerClusterer>
  </GoogleMap>
));

class DemoApp extends React.PureComponent {
  componentWillMount() {
    this.setState({ markers: [], isOpen: false, InfoWindowobject: {} });
  }

  componentDidMount() {
    axios({
      url: "API",

    }).then(res => {
      this.setState({ markers: res.data.data.list });
    });
  }

  render() {
    return (
      <MapWithAMarkerClusterer
        markers={this.state.markers}
        isOpen={this.state.isOpen}
        InfoWindowobject={this.state.InfoWindowobject}
      />
    );
  }
}

参考： https://tomchentw.github.io/react-google-maps/#markerclusterer

Answer 1

onMarkerClick 调用 API 和（获取后）两个处理程序：setInfoWindow()、'onToggleOpen`。

两个处理程序都调用带有状态更改的结果并强制重新呈现嵌入式组件 (<GoogleMap/>)。

您应该将 <MarkerClusterer/> 与处理程序一起嵌入，并将此增强组件作为子组件传递给 <GoogleMap/> 组件（或仅在内部渲染）。

Answer 2

这是预期的行为，因为 re-render 会在每次状态更改时发生。为了 prevent re-render 你可以考虑用 shouldUpdate higher-order component 包装 MarkerClusterer 组件来让 React 知道组件是否应该受到改变状态的影响演示如下：

const MyMarkerClusterer = shouldUpdate(checkPropsChange)(props => {
  const {onMarkerClick,markers,...clusterProps}  = props;
  return (
    <MarkerClusterer 
    {...clusterProps}      
    >
      {markers.map(marker => (
        <Marker
          key={marker.photo_id}
          position={{ lat: marker.latitude, lng: marker.longitude }}
          onClick={onMarkerClick.bind(this, marker)}
        />
      ))}
    </MarkerClusterer>
  );
});

哪里

const checkPropsChange = (props, nextProps) => {
  return nextProps.markers.length !== props.markers.length; //re-render only if markers prop changed 
};

Here is a demo

为什么要在标记点击事件上重新渲染地图？

Why map re rendering on marker click event?

javascript

google-maps

reactjs

recompose

react-google-maps