我有一个使用arcgis javascript API构建的应用程序。它使用要素图层提取信息并允许在地图上进行不同的搜索，但是15个要素图层确实使我的客户的服务器陷入瘫痪，因此我们正在寻找替代方法。我试图找到其他与之兼容的方法并不会杀死我的应用程序的功能，但是我还没有找到解决方案。该应用程序当前具有以下搜索功能：
1）显示图层中的所有要素
2）在可设置的半径内显示图层中的所有要素
3）在用户当前位置的可设置半径范围内显示所有功能（如果允许访问）
通过在图层上执行查询（使用queryFeatures（））以仅显示具有categoryX和/或industryY的要素，可以将上述所有搜索选项的显示要素缩小。
无论何时打开或关闭要素图层，所有功能都像是一种魅力，它不仅为服务器提供了帮助。
有没有一种方法可以不依赖要素图层来完成所有这些工作？
编辑：这是我正在做的一个例子：http://developers.arcgis.com/javascript/sandbox/sandbox.html?sample=query_buffer
最佳答案
使用要素图层可让您直接在客户端上具有几何。在某些情况下（例如，如果您需要编辑要素），必须在客户端上具有几何形状，但在其他情况下，这不是更好的选择。
为了实现您的目标，您可以只使用许多ArcGISDynamicMapServiceLayer并标识或查询任务以从服务器获取信息。
编辑：我已经修改了您发布的示例
var map;
require([
"esri/map", "esri/layers/ArcGISDynamicMapServiceLayer",
"esri/tasks/query", "esri/geometry/Circle",
"esri/graphic", "esri/InfoTemplate", "esri/symbols/SimpleMarkerSymbol",
"esri/symbols/SimpleLineSymbol", "esri/symbols/SimpleFillSymbol", "esri/renderers/SimpleRenderer",
"esri/config", "esri/Color", "dojo/dom","esri/tasks/QueryTask", "dojo/domReady!"
], function(
Map, ArcGISDynamicMapServiceLayer,
Query, Circle,
Graphic, InfoTemplate, SimpleMarkerSymbol,
SimpleLineSymbol, SimpleFillSymbol, SimpleRenderer,
esriConfig, Color, dom, QueryTask
) {
esriConfig.defaults.io.proxyUrl = "/proxy/";
map = new Map("mapDiv", {
basemap: "streets",
center: [-95.249, 38.954],
zoom: 14,
slider: false
});
var dynamicMapServiceLayer = new ArcGISDynamicMapServiceLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer");
var queryTask = new QueryTask("http://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/0");
var circleSymb = new SimpleFillSymbol(
SimpleFillSymbol.STYLE_NULL,
new SimpleLineSymbol(
SimpleLineSymbol.STYLE_SHORTDASHDOTDOT,
new Color([105, 105, 105]),
2
), new Color([255, 255, 0, 0.25])
);
var circle;
var symbol = new SimpleMarkerSymbol(
SimpleMarkerSymbol.STYLE_CIRCLE,
12,
new SimpleLineSymbol(
SimpleLineSymbol.STYLE_NULL,
new Color([247, 34, 101, 0.9]),
1
),
new Color([207, 34, 171, 0.5])
);
//when the map is clicked create a buffer around the click point of the specified distance.
map.on("click", function(evt){
circle = new Circle({
center: evt.mapPoint,
geodesic: true,
radius: 1,
radiusUnit: "esriMiles"
});
map.graphics.clear();
map.infoWindow.hide();
var graphic = new Graphic(circle, circleSymb);
map.graphics.add(graphic);
var query = new Query();
query.geometry = circle.getExtent();
//use a fast bounding box query. will only go to the server if bounding box is outside of the visible map
require([
"esri/tasks/query"
], function (Query) {
var query = new Query();
query.spatialRelationship = Query.SPATIAL_REL_CONTAINS;
query.geometry = circle;
query.returnGeometry = true;
queryTask.execute(query, function (fset1) {
dojo.forEach(fset1.features, function (feature, i) {
console.log("feature", feature);
feature.setSymbol(symbol);
map.graphics.add(feature);
});
});
});
});
function selectInBuffer(response){
var feature;
var features = response.features;
var inBuffer = [];
//filter out features that are not actually in buffer, since we got all points in the buffer's bounding box
for (var i = 0; i < features.length; i++) {
feature = features[i];
if(circle.contains(feature.geometry)){
inBuffer.push(feature.attributes[featureLayer.objectIdField]);
}
}
var query = new Query();
query.objectIds = inBuffer;
//use a fast objectIds selection query (should not need to go to the server)
featureLayer.selectFeatures(query, FeatureLayer.SELECTION_NEW, function(results){
var totalPopulation = sumPopulation(results);
var r = "";
r = "<b>The total Census Block population within the buffer is <i>" + totalPopulation + "</i>.</b>";
dom.byId("messages").innerHTML = r;
});
}
function sumPopulation(features) {
var popTotal = 0;
for (var x = 0; x < features.length; x++) {
popTotal = popTotal + features[x].attributes["POP2000"];
}
return popTotal;
}
});
关于javascript - 替代arcgis featureLayer？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/27492635/