为什么传单地图不会在反应应用程序上呈现

Question

I included leaflet map with js implementation instead of jsx implementation but I have a problem as it overflows its scope.

this is how I imported leaflet:

import L from 'leaflet';

and implemented:

componentDidMount() {
    // create map
    this.map = L.map('map', {
      center: [49.8419, 24.0315],
      zoom: 16,
      layers: [
        L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
          attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
        }),
      ]
    });
  }

and usage:

<div id={"map"} > 

and this is what i got

Answer 1

You have not added the leaflet css file in your index.html .

For leaflet version 1.3.4 , add the following to index.html

<link rel="stylesheet" href="https://unpkg.com/leaflet@1.3.4/dist/leaflet.css"
   integrity="sha512-puBpdR0798OZvTTbP4A8Ix/l+A4dHDD0DGqYW6RQ+9jxkRFclaxxQb/SJAWZfWAkuyeQUytO7+7N4QKrDh+drA=="
   crossorigin=""/>  

In your map component css file, override the leaflet-container class with desired height and width.

.leaflet-container {
  height: 600px;
  width: 100%;
}

Once you have added that, use Map and TileLayer Components of react-leaflet to render map.

import React, { Component } from "react";
import ReactDOM from "react-dom";
import { Map, TileLayer } from "react-leaflet";
import "./styles.css";

class App extends Component {
  state = {
    center: [51.505, -0.091],
    zoom: 13
  };

  render() {
    return (
      <div>
        <Map center={this.state.center} zoom={this.state.zoom}>
          <TileLayer
            attribution='&amp;copy <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
            url="https://{s}.tile.osm.org/{z}/{x}/{y}.png"
          />
        </Map>
      </div>
    );
  }
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);  

You can find working code here. https://codesandbox.io/s/2wnv7o1mlr

Answer 2

Yeah you're missing the css file.

incidentally this is not how you should be using react-leaflet . componentDidMount is not the place for doing what you're doing. Put that in the render like

import { Map, TileLayer } from 'react-leaflet'; 
<Map>
      <TileLayer url="'http://{s}.tile.osm.org/{z}/{x}/{y}.png'" />
</Map>