const map = new Map({
target: 'map',
layers: [
new TileLayer({
source: new XYZ({
url: 'http://cache1./arcgis/rest/services/ChinaOnline' +
'StreetPurplishBlue/MapServer/tile/{z}/{y}/{x}'
})
})
],
view: new View({
center: [113.53450137499999, 34.44104525],
projection: 'EPSG:4326',
zoom: 6
})
});

function getJSON (url, callback) {
const xhr = new XMLHttpRequest();
xhr.responseType = 'json';
xhr.open('get', url, true);
xhr.onload = function () {
if (xhr.status >= 200 && xhr.status < 300) {
callback(xhr.response);
} else {
throw new Error(xhr.statusText);
}
};
xhr.send();
}
 
getJSON('data.json', function (res) {
if (res) {
var data = res.locations;
var geoCoordMap = res.coordinates;
var convertData = function (data) {
var res = [];
for (var i = 0; i < data.length; i++) {
var geoCoord = geoCoordMap[data[i].name];
if (geoCoord) {
res.push({
name: data[i].name,
value: geoCoord.concat(data[i].value)
});
}
}
return res;
};
var option = {
title: {
text: '全國(guó)主要城市空氣質(zhì)量',
subtext: '',
sublink: '',
left: 'center',
textStyle: {
color: '#fff'
}
},
tooltip: {
trigger: 'item'
},
openlayers: {},
legend: {
orient: 'vertical',
y: 'top',
x: 'right',
data: ['pm2.5'],
textStyle: {
color: '#fff'
}
},
series: [
{
name: 'pm2.5',
type: 'scatter',
data: convertData(data),
symbolSize: function (val) {
return val[2] / 10;
},
label: {
normal: {
formatter: '',
position: 'right',
show: false
},
emphasis: {
show: true
}
},
itemStyle: {
normal: {
color: '#ddb926'
}
}
},
{
name: 'Top 5',
type: 'effectScatter',
data: convertData(data.sort(function (a, b) {
return b.value - a.value;
}).slice(0, 6)),
symbolSize: function (val) {
return val[2] / 10;
},
showEffectOn: 'render',
rippleEffect: {
brushType: 'stroke'
},
hoverAnimation: true,
label: {
normal: {
formatter: '',
position: 'right',
show: true
}
},
itemStyle: {
normal: {
color: '#f4e925',
shadowBlur: 10,
shadowColor: '#333'
}
},
zlevel: 1
}]
};
}
});