ol-地图上添加图标

先总结：用到的核心知识

添加图标，首先要创建一个图层，然后把图层添加到地图上

vecSource = new ol.source.Vector({

    features: []

});

vecLayer = new ol.layer.Vector({

    renderMode: 'image',

    source: vecSource,

    style: function(feat) {

        return styleFunction(feat, map);

    },

    zIndex: 10

});

map.addLayer(vecLayer);

styleFunction对图标进行一些样式处理

function styleFunction(feat, map) {

    const zoom = map.getView().getZoom();

    let scale = zoom / 5;

    if (scale > 1.2) scale = 1.2;

    let icon = '';

    let zIndex = 1;

    icon = './static/img/ship-default.svg';



    let styles = [];

    // 告警船是系统船时不显示

    styles.push(

        new ol.style.Style({

            image: new ol.style.Icon({

                anchor: [0.5, 0.5], // 锚点 默认值是图标中心

                src: icon, // 图片路径

                scale: scale,

                rotation: (Math.PI / 180) * 20

            }),



            zIndex: zIndex

        })

    );

    return styles;

}

获取数据后，拿到经纬度，然后在地图上添加这些图标点，可以给点添加一些feature，方便后续操作图标的时候获取当前图标的信息。feature就是styleFunction函数中拿到的feat
 

function addWarnMapFeatures() {

    let features = [];

    let coords = [];

    for (let i = 0; i < shipList.length; i++) {

        const r = shipList[i];

        shipList[i].flag = 'LS';

        let lonlat = [r.lon, r.lat];

        let coord = ol.proj.transform(lonlat, 'EPSG:4326', 'EPSG:3857');

        features.push(

            new ol.Feature({

                geometry: new ol.geom.Point(coord),

                rotation: r.sog,

                mmsi: r.mmsi,

                name: r.name,

                shipInfo: r

            })

        );

        coords.push(coord);

    }

    vecSource.addFeatures(features);

    // 目的是定位到船舶所在的位置   

if (coords.length > 0) {

        const pts = new ol.geom.MultiPoint(coords);

        // 获取几何体的范围 pts.getExtent()

        map.getView().fit(pts.getExtent());

        // map.getView().setZoom(11);

    }

}

下面这两行代码是定位到当前经纬度集合的位置附近

const pts = new ol.geom.MultiPoint(coords);

        // 获取几何体的范围 pts.getExtent()

map.getView().fit(pts.getExtent());

清除图层

vecSource.clear()