openlayer 投影转换

需求:openlayer 实现投影转换

源码:https://pan.baidu.com/s/1-euCKVEPGcQXn_FJ6tda_A   提取码: 8af8 

源码解压后  文件放到  tomcat 或任意网络服务(否则会有跨域问题) 双击 ol_wmts.html 浏览器打开即可

(其中加载了geoserver 的一个wmts服务,需要安装geoserver)

 

参考资料:

资料1:https://blog.csdn.net/SmileCoffin/article/details/56278882   

资料2:https://www.cnblogs.com/w-wanglei/p/6538061.html      

资料3:https://openlayers.org/en/latest/examples/reprojection.html

资料4:http://datav.aliyun.com/tools/atlas/#&lat=33.50475906922609&lng=104.2822265625&zoom=4

资料5:https://www.npmjs.com/package/world-atlas

 

代码整体参考资料1 ,不能完全满足需求,因为其并非 “同一个map的投影转换”,而是 “不同投影的两个map之间的对比”

参考资料2 中的 “6.如何改变地图的投影系” 章节实现了对 vector 的投影转换

资料3 是官方示例,参考资料3实现了对 raster 的投影转换

资料4 是在线获取 中国地区行政区划图的 geojson格式数据

资料5 是在线获取 全球国家边界的 topojson格式数据(本案例里没有用到)

 

感谢以上作者的帮助

openlayer 接触不多,代码不完美,仅供参考。

 

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title></title>
    <script src="./lib/ol/ol.js"></script>
    <script src="./lib/ol/proj4.js"></script>
    <link href="./css/ol.css" rel="stylesheet" />
    <style type="text/css">
        body,html,div{
            border:none;padding:0;margin:0;
            font-size:14px;
            font-family:"微软雅黑";
        }
        #menu{
            width:100%;
            height:20px;         
            padding:5px 10px;
            left:10px;    
        }
        .container{
            float:left;
            width:90%;
            height:500px;
            margin:0 5px;
            margin-left:10px; 
        }        
        .map{
            float:left;
            width:100%;
            height:100%;
            border:1px dashed red;
        }
    </style>
    <script type="text/javascript">
        window.onload = function () {        
        //初始化矢量图层
        var vector = new ol.layer.Vector({
              source: new ol.source.Vector({
            url: '/ol/data/geojson/countries-110m.json',
            format:new ol.format.GeoJSON()
              })
        }); 
        
        //osm tile layer
        var tile = new ol.layer.Tile({
          source:new ol.source.OSM()
        })

        //geoserver 默认自带的 wmts 图层
        //设置地图投影
        var projection = new ol.proj.Projection({
          code: 'EPSG:4326',//投影编码
          units: 'degrees',
          axisOrientation: 'neu'
        });



        var layer_wmts = new ol.layer.Tile({
          source: new ol.source.WMTS({
            url: 'http://localhost:8088/geoserver/gwc/service/wmts',//注意这里,笔者安装geoserver时配置的端口是 8088,不是默认的8080
            layer: 'nurc:Img_Sample',
            matrixSet: 'EPSG:4326',
            format: 'image/png',
            projection: projection,
            tileGrid: new ol.tilegrid.WMTS({
              tileSize: [256, 256],
              extent: [-180.0, -90.0, 180.0, 90.0],//范围
              origin: [-180.0, 90.0],
              resolutions: [0.703125, 0.3515625, 0.17578125, 0.087890625, 0.0439453125, 0.02197265625, 0.010986328125, 0.0054931640625, 0.00274658203125, 0.001373291015625, 6.866455078125E-4, 3.4332275390625E-4, 1.71661376953125E-4, 8.58306884765625E-5, 4.291534423828125E-5, 2.1457672119140625E-5, 1.0728836059570312E-5, 5.364418029785156E-6, 2.682209014892578E-6, 1.341104507446289E-6, 6.705522537231445E-7, 3.3527612686157227E-7],
              matrixIds: ['EPSG:4326:0', 'EPSG:4326:1', 'EPSG:4326:2', 'EPSG:4326:3', 'EPSG:4326:4', 'EPSG:4326:5', 'EPSG:4326:6', 'EPSG:4326:7', 'EPSG:4326:8', 'EPSG:4326:9', 'EPSG:4326:10', 'EPSG:4326:11', 'EPSG:4326:12', 'EPSG:4326:13', 'EPSG:4326:14', 'EPSG:4326:15', 'EPSG:4326:16', 'EPSG:4326:17', 'EPSG:4326:18', 'EPSG:4326:19', 'EPSG:4326:20', 'EPSG:4326:21'],
            }),
            //
            style: 'raster',
            wrapX: true
          })
        });
 
            //初始化地图
            var map = new ol.Map({
                layers: [
            tile,
                    vector,
            layer_wmts
                ],
                //渲染方式
                render: 'canvas',
                target: 'map',
                view: new ol.View({
                    //EPSG:3857投影
                    projection: ol.proj.get('EPSG:3857'),
                    resolutions: [65536, 32768, 16384, 8192, 4096, 2048, 1024, 512,256],
                    center:ol.proj.transform([120, 37], 'EPSG:4326', 'EPSG:3857'),
                    zoom:2
                })
            });
            //显示网格参考
            var graticule = new ol.Graticule({
                map: map
            })

            //定义球形摩尔魏特投影坐标系
            proj4.defs('ESRI:53009', '+proj=moll +lon_0=0 +x_0=0 +y_0=0 +a=6371000 +b=6371000 +units=m +no_defs');
 
            //定义球形摩尔魏特投影
            var sphereMollweideProjection = new ol.proj.Projection({
                //编号
                code: 'ESRI:53009',
                //显示范围
                //extent: [-909954.605703328, -909954.605703328, 19009954.605703328, 19009954.605703328],
          extent: [-20000000, -9000000, 20000000, 10000000],
                //世界经纬度范围
                worldExtent: [-179, -90, 179, 90]
            });
                
        //进行投影转换   将之前的map 及包含的图层进行转换
        document.getElementById('projection').onclick = function () {
          //raster trans
          var view= new ol.View({
            projection: sphereMollweideProjection,
            resolutions: [65536, 32768, 16384, 8192, 4096, 2048, 1024, 512,256],
            center: ol.proj.transform([0, 10], 'EPSG:4326', 'EPSG:3857'),
            zoom: 1
          })
          map.setView(view);
            
          //vector trans
          map.getLayers().getArray().forEach(function (layer) {
            if  (layer instanceof ol.layer.Vector) {
              var features = layer.getSource().getFeatures();
              for( i = 0; i < features.length; i += 1) {
                features[i].getGeometry().transform(ol.proj.get('EPSG:3857'), sphereMollweideProjection);
              }
            }
          });
        };
        };
        
    </script>
</head>
<body>
    <div id="menu">
        <label class="title" for="projection">
            地图投影转换演示:<button id="projection">投影转换</button>
        </label>
    </div>
    <div class="container">
        <label>投影坐标系(EPSG:3857)</label>
        <div id="map" class="map"></div>
    </div>

</body>
</html>

 

结果展示:

转换后

 

posted @ 2020-03-24 17:07  mumu122  阅读(1451)  评论(0编辑  收藏  举报