反应设置状态未定义?

它在navigator object中非常简单您不能访问这个对象,因为它有window object的引用,所以我在promise中使用navigator object,如果navigator给了我纬度和经度,那么我就解析我的promise如果不拒绝promise并返回promise。

在 ComponentDidMount 我使用await调用函数,因为它返回承诺,在我有值之后,我设置状态

getWeather 功能

import React from "react";
import axios from "axios";
// import WeatherGadget from './weather.component'

export default class WeatherApi extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      city: null,
      lat: 0,
      lon: 0,
      wind: 0,
      weather: 0,
      icon: null
    };
  }


  async componentDidMount() {
    const location = await this.location();
    location && this.setState({ lat: location.lat, lon: location.long });
    location && this.getWeather();
  }
  location = () => {
   //return the promise that contain the navigator object
    return new Promise((resolve, reject) => {
      try {
        navigator.geolocation.getCurrentPosition(position => {
          resolve({
            lat: position.coords.latitude,
            long: position.coords.longitude
          });
        });
      } catch (error) {
        let temp = {
          lat: 24.8607,
          long: 67.0011
        };
        reject(temp);
      }
    });
  };
//calling weather api
  getWeather = async () => {
    const url = `https://api.openweathermap.org/data/2.5/onecall?lat=${
      this.state.lat
    }&lon=${this.state.lon}&appid=8821HIDDEN4e9d78`;
    console.log("url", url);
    try {
      const res = await axios.get(url);
      if (res) {
        console.log("res", res.data)
        const weatherObj = res.data;
        console.log("===", weatherObj);
        const currentWeather = weatherObj.current.temp;
        const windSpeed = weatherObj.current.wind_speed;
        const icon = weatherObj.current.weather[0].icon;
        this.setState({ wind: windSpeed, weather: currentWeather, icon: icon });
      }
    } catch (error) {
      console.log("error", error)
    }
  };
  render() {
    return (
      <div>
        {/* <WeatherGadget city={this.state.city}  wind ={this.state.wind} weather={this.state.weather} icon={this.state.icon}/> */}
        <p> Lat: {this.state.lat}</p>
        <p> Lng: {this.state.lon}</p>
        <p> Weather: {this.state.weather}</p>
        <p>Wind: {this.state.wind}</p>

      </div>
    );
  }
}