Question

使用openlayer在平铺背景上显示kml文件的基本脚本;我刚刚从版本2切换到4.65，如何缩放到kml几何体的极限（这里是“矢量”）？

        var wmsSource = new ol.source.TileWMS({
            url: "https://sedac.ciesin.columbia.edu/geoserver/wms",
            params: {"LAYERS": "other:wwf-terrestrial-biomes", "TILED": true},
            serverType: "geoserver"
          });

        var wmsLayer = new ol.layer.Tile({
            opacity: 0.15,
            visible: true,
            source: wmsSource
          });

        var vector = new ol.layer.Vector({
            source: new ol.source.Vector({
            url: "kml_file.kml",
            format: new ol.format.KML()
        })
    });

        var map = new ol.Map({
            target: "map-canvas",
            layers: [wmsLayer, vector],
            controls: ol.control.defaults().extend([
                new ol.control.ScaleLine({units: "metric"}), 
                new ol.control.FullScreen()
            ]),
            view: new ol.View({
                center: ol.proj.transform([37.41, 8.82], "EPSG:4326", "EPSG:3857"),
                zoom: 3
            })
        });

我想替换zoom: 3并让地图居中并扩展到kml限制？

注意：我将kmllayer.events.register("loadend", kmllayer, function(evt){map.zoomToExtent(kmllayer.getDataExtent())});与OpenLayers2 ...

一起使用

Answer 1

以下应该做你想做的事

var vectorSource = vector.getSource();
vectorSource.once('change', function(e){
    if (vectorSource.getState() === 'ready') {
        var extent = vectorSource.getExtent();
        map.getView().fit(extent);
    }
});

解决方案主要改编自How to get the extent of a GeoJSON vector source?（更改了变量名称＆amp;删除了map.getView().fit中的第二个参数（旧时需要，现在是可选的，大部分时间都不需要，就像这里一样）

Answer 2

好的，我需要将kml源声明为单独的new ol.source.Vector变量，此处为vectorSource，并从此变量中读取.getExtent()，而不是ol.layer.Vector：< / p>

        var wmsSource = new ol.source.TileWMS({
            url: "https://sedac.ciesin.columbia.edu/geoserver/wms",
            params: {"LAYERS": "other:wwf-terrestrial-biomes", "TILED": true},
            serverType: "geoserver"
          });

        var wmsLayer = new ol.layer.Tile({
            opacity: 0.15,
            visible: true,
            source: wmsSource
          });

        var vectorSource = new ol.source.Vector({
            url: "'.$kml_f.'",
            format: new ol.format.KML()
        });

        var vector = new ol.layer.Vector({
            source: vectorSource
    });

        var map = new ol.Map({
            target: "map-canvas",
            layers: [wmsLayer, vector],
            controls: ol.control.defaults().extend([
                new ol.control.ScaleLine({units: "metric"}), 
                new ol.control.FullScreen()
            ]),
            view: new ol.View({
                center: ol.proj.transform([37.41, 8.82], "EPSG:4326", "EPSG:3857"),
                zoom: 4,
            })
        });

        vector.once("change", function(e){
                var extent = vectorSource.getExtent();
                map.getView().fit(extent);
        });

感谢您的帮助！

openlayers3：居中和缩放范围达到KML限制

2 个答案: