<p style="text-align:center"><img src="https://simg.open-open.com/show/a0013026d23b2828abda6f5317b52a37.jpg"></p>    <p>实现功能：打开网页时显示用户所在城市的天气状况，在输入框输入城市可查询其它城市。</p>    <p>实现过程：先调用百度地图的API来获取用户所在的城市，随后调用聚合数据的天气API将数据放在页面上。由于ajax不支持跨域，所以采用了jsonp的方式来调用数据。</p>    <p> </p>    <pre>  <code class="language-javascript">//调用jsonp函数请求当前所在城市  jsonp('https://api.map.baidu.com/api?v=2.0&ak=Dv1NMU23dh1sGS9n2tUouDEYY96Dfzh3&s=1&callback=getCity');  window.onload=function(){      //请求天气车数据      btn.onclick=function (){          jsonp(createUrl());      }  };  function getCity(){      function city(result){          jsonp(createUrl(result.name));      }      var cityName = new BMap.LocalCity();      cityName.get(city);  }  // 数据请求函数  function jsonp(url){      var script = document.createElement('script');      script.src = url;      document.body.insertBefore(script, document.body.firstChild);      document.body.removeChild(script);  }  //数据请求成功回调函数，用于将获取到的数据放入页面相应位置  function getWeather(response) {      var oSpan = document.getElementsByClassName('info');      var data = response.result.data;      oSpan[0].innerHTML=data.realtime.city_name;      oSpan[1].innerHTML=data.realtime.date;      oSpan[2].innerHTML='星期'+data.weather[0].week;      oSpan[3].innerHTML=data.realtime.weather.info;      oSpan[4].innerHTML=data.realtime.weather.temperature+'℃';      oSpan[5].innerHTML=data.realtime.wind.direct;      oSpan[6].innerHTML=data.realtime.weather.humidity+'%';      oSpan[7].innerHTML=data.realtime.time;      oSpan[8].innerHTML=data.life.info.ziwaixian[0];      oSpan[9].innerHTML=data.life.info.xiche[0];      oSpan[10].innerHTML=data.life.info.kongtiao[0];      oSpan[11].innerHTML=data.life.info.chuanyi[0];        var aDiv = document.getElementsByClassName('future_box');      for(var i=0; i<aDiv.length; i++){          var aSpan = aDiv[i].getElementsByClassName('future_info');          aSpan[0].innerHTML = data.weather[i].date;          aSpan[1].innerHTML = '星期'+data.weather[i].week;          aSpan[2].innerHTML =data.weather[i].info.day[1];          aSpan[3].innerHTML = data.weather[i].info.day[2]+'℃';      }      changeImg(response);  }  //根据获取到的数据更改页面中相应的图片  function changeImg(data){      var firstImg = document.getElementsByTagName("img")[0];      var firstWeatherId=data.result.data.realtime.weather.img;      chooseImg(firstWeatherId,firstImg);        var aImg = document.getElementById('future_container').getElementsByTagName('img');      for(var j=0; j<aImg.length; j++){          var weatherId = data.result.data.weather[j].info.day[0];          chooseImg(weatherId,aImg[j]);      }  }  //选择图片  function chooseImg(id,index){      switch(id){          case '0':              index.src='images/weather_icon/1.png';              break;          case '1':              index.src='images/weather_icon/2.png';              break;          case '2':              index.src='images/weather_icon/3.png';              break;          case '3':          case '7':          case '8':              index.src='images/weather_icon/4.png';              break;          case '6':              index.src='images/weather_icon/6.png';              break;          case '13':          case '14':          case '15':          case '16':              index.src='images/weather_icon/5.png';              break;          case '33':              index.src='images/weather_icon/7.png';              break;          default:              index.src='images/weather_icon/8.png';      }  }  //根据城市名创建请求数据及url  function createUrl(){      var cityName = '';      if(arguments.length == 0) {          cityName = document.getElementById('text').value;      }else{          cityName = arguments[0];      }      var url = 'https://op.juhe.cn/onebox/weather/query?cityname=' + encodeURI(cityName) + '&key=1053d001421b886dcecf81a38422a1a2&callback=getWeather';      return url;  }  </code></pre>    <p> </p>    <p> </p>    <p> </p>