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iclient Graphic 性能问题
6EXP 2018年04月11日

使用产品:iclient for openlayer 9D 
问题详细描述:可视化点图层中的第一个示例, 高效率点图层纽约出租车18万点-canvas渲染性能问题
问题重现步骤: 1、打开官方示例,可视化--高效率点图层--第一个canvas渲染;2、修改编辑器中代码;3、增加定时器,定时刷新页面Graphic图层数据;

问题现象:最后页面直接崩溃,内存增加过快,倒是页面崩溃。


修改后的代码如下:

<!DOCTYPE html>
<html lang="en-US">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=Edge">
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no, width=device-width">
    <title data-i18n="resources.title_graphiclayerCanvas"></title>
    <script type="text/javascript" include="randomcolor" src="../js/include-web.js"></script>
    <script type="text/javascript" src="../../dist/include-openlayers.js"></script>
    <style>
        .ol-popup {
            position: absolute;
            background-color: white;
            -webkit-filter: drop-shadow(0 1px 4px rgba(0, 0, 0, 0.2));
            filter: drop-shadow(0 1px 4px rgba(0, 0, 0, 0.2));
            padding: 15px;
            border-radius: 10px;
            border: 1px solid #cccccc;
            bottom: 12px;
            left: -50px;
            min-width: 50px;
        }

        .ol-popup:after, .ol-popup:before {
            top: 100%;
            border: solid transparent;
            content: " ";
            height: 0;
            width: 0;
            position: absolute;
            pointer-events: none;
        }

        .ol-popup:after {
            border-top-color: white;
            border-width: 10px;
            left: 48px;
            margin-left: -10px;
        }

        .ol-popup:before {
            border-top-color: #cccccc;
            border-width: 11px;
            left: 48px;
            margin-left: -11px;
        }
    </style>
</head>
<body style=" margin: 0;overflow: hidden;background: #fff;width: 100%;height:100%">
<div id="map" style="width: 100%;height:100%"></div>
<div id="popup" class="ol-popup">
    <div id="popup-content"></div>
</div>
<script type="text/javascript">
    var url = (window.isLocal ? document.location.host : "http://support.supermap.com.cn:8090") + "/iserver/services/map-china400/rest/maps/ChinaDark";

    var map;
    var colorCount = 10;
    var colors = getRandomColors(colorCount);

    
    new ol.supermap.MapService(url).getMapInfo(function (serviceResult) {
        var mapJSONObj = serviceResult.result;
        var container = document.getElementById('popup');
        var content = document.getElementById('popup-content');
        var overlay = new ol.Overlay(({
            element: container,
            autoPan: true,
            autoPanAnimation: {
                duration: 250
            }
        }));
        map = new ol.Map({
            target: 'map',
            controls: ol.control.defaults({attributionOptions: {collapsed: false}})
                .extend([new ol.supermap.control.Logo()]),
            view: new ol.View({
                center: ol.proj.transform([-73.9286, 40.75], 'EPSG:4326', 'EPSG:3857'),
                zoom: 12,
                projection: 'EPSG:3857'
            }),
            overlays: [overlay],
            renderer: ['canvas']
        });
        var options = ol.source.TileSuperMapRest.optionsFromMapJSON(url, mapJSONObj);
        var layer = new ol.layer.Tile({
            source: new ol.source.TileSuperMapRest(options)
        });
        map.addLayer(layer);
    });
    var randomCircleStyles = [];
    for (var i = 0; i < colorCount; i++) {
        randomCircleStyles.push(new ol.style.RegularShape({
            radius: Math.floor(Math.random() * 10 + 1),
            fill: new ol.style.Fill({
                color: colors[i]
            }),
            stroke: new ol.style.Stroke({
                color: colors[i]
            }),
            points: 3,
        }));
    }
    function show(){
        $.get('../data/nyc_taxi.json', function (nycData) {
            var count = nycData.features.length;    //矢量点的个数
            var graphics = new Array(count);
            for (var i = 0; i < count; ++i) {
                var coordinates = nycData.features[i].geometry.coordinates;
                if (coordinates[0] === coordinates[1]) {
                    continue;
                }
                coordinates = ol.proj.transform(coordinates, 'EPSG:4326', 'EPSG:3857');
                graphics[i] = new ol.Graphic(new ol.geom.Point(coordinates));
                graphics[i].setStyle(randomCircleStyles[Math.floor(Math.random() * colorCount)]);
            }
            map.once('postrender', function () {
                var graphicLayer = new ol.layer.Image({
                    source: new ol.source.Graphic({
                        graphics: graphics,
                        map: map,
                        onClick: function (graphic) {
                            if (graphic) {
                                var coords = graphic.getGeometry().getCoordinates();
                                content.innerHTML = resources.text_coordinate + ":[" + coords[0] + "," + coords[1] + "]";
                                overlay.setPosition(graphic.getGeometry().getCoordinates());
                                return;
                            }
                            overlay.setPosition(undefined);
                        }
                    })
                });
                map.addLayer(graphicLayer);
            })
        });
    }
    function getRandomColors(count) {
        return randomColor({
            luminosity: 'bright',
            hue: 'random',
            alpha: 0.5,
            format: 'rgba',
            count: count
        });
    }
    show();
    setInterval(function () {
        show();
    }, 60 * 1000);
</script>
</body>
</html>

2 个回答

setInterval(function () { show(); }, 60 * 1000);增加一步,

map.removeLayer("graphicLayer");

同样存在该性能问题。有什么办法可以解决呢?求助

6EXP 2018年04月11日

您好,清除图层的时候没有清除graphics,导致内存一直累加,这是个缺陷,已排入迭代计划,2-3周内解决。

4,524EXP 2018年04月12日
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