我正在尝试使用Javascript创建一个SELECT BUFFER，但我无法正确完成。我已经能够创建程序的缓冲区部分，它工作。但是，我无法使用缓冲区来选择落在其中的点。我想知道是否有人可以帮助我。
以下是代码：
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<!--The viewport meta tag is used to improve the presentation and behavior of the samples
on iOS devices-->
<meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">
<title>Buffer</title>
<link rel="stylesheet" href="http://js.arcgis.com/3.14/dijit/themes/claro/claro.css">
<link rel="stylesheet" href="http://js.arcgis.com/3.14/esri/css/esri.css">
<style>
html, body {
height: 100%;
width: 100%;
margin: 0;
padding: 0;
overflow:hidden;
}
#leftPane{
color:#000;
width:250px;
padding-bottom:15px;
}
#map{
padding:0;
}
.details{
font-size:14px;
font-weight:600;
padding-bottom:20px;
}
button{
margin:2px;
cursor:pointer;
}
</style>
<script src="http://js.arcgis.com/3.14/"></script>
<script>
var map, tb;
require(["dojo/dom",
"dojo/_base/array",
"dojo/parser",
"dojo/query",
"dojo/on",
"esri/Color",
"esri/config",
"esri/map",
"esri/graphic",
"esri/geometry/normalizeUtils",
"esri/tasks/GeometryService",
"esri/tasks/BufferParameters",
"esri/toolbars/draw",
"esri/symbols/SimpleMarkerSymbol",
"esri/symbols/SimpleLineSymbol",
"esri/symbols/SimpleFillSymbol",
"esri/layers/FeatureLayer",
"esri/tasks/query",
"dijit/layout/BorderContainer",
"dijit/layout/ContentPane",
"dijit/form/Button", "dojo/domReady!"
],
function(dom, array, parser, query, on, Color, esriConfig, Map, Graphic, normalizeUtils, GeometryService, BufferParameters, Draw, SimpleMarkerSymbol, SimpleLineSymbol, SimpleFillSymbol, FeatureLayer, Query){
parser.parse();
esriConfig.defaults.geometryService = new GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
esriConfig.defaults.io.proxyUrl = "/proxy/";
esriConfig.defaults.io.alwaysUseProxy = false;
//Setup button click handlers
on(dom.byId("clearGraphics"), "click", function(){
if(map){
map.graphics.clear();
}
});
//click handler for the draw tool buttons
query(".tool").on("click", function(evt){
if(tb){
tb.activate(evt.target.id);
}
});
map = new Map("map", {
basemap: "streets",
center: [-82.44, 28.3],
zoom: 13
});
map.on("load", initToolbar);
function initToolbar(evtObj) {
tb = new Draw(evtObj.map);
tb.on("draw-end", doBuffer);
}
function doBuffer(evtObj) {
tb.deactivate();
var geometry = evtObj.geometry, symbol;
switch (geometry.type) {
case "point":
symbol = new SimpleMarkerSymbol(SimpleMarkerSymbol.STYLE_SQUARE, 10, new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, new Color([255,0,0]), 1), new Color([0,255,0,0.25]));
break;
case "polyline":
symbol = new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASH, new Color([255,0,0]), 1);
break;
case "polygon":
symbol = new SimpleFillSymbol(SimpleFillSymbol.STYLE_NONE, new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASHDOT, new Color([255,0,0]), 2), new Color([255,255,0,0.25]));
break;
}
var graphic = new Graphic(geometry, symbol);
map.graphics.add(graphic);
//setup the buffer parameters
var params = new BufferParameters();
params.distances = [ dom.byId("distance").value ];
params.outSpatialReference = map.spatialReference;
params.unit = GeometryService[dom.byId("unit").value];
//normalize the geometry
normalizeUtils.normalizeCentralMeridian([geometry]).then(function(normalizedGeometries){
var normalizedGeometry = normalizedGeometries[0];
if (normalizedGeometry.type === "polygon") {
//if geometry is a polygon then simplify polygon. This will make the user drawn polygon topologically correct.
esriConfig.defaults.geometryService.simplify([normalizedGeometry], function(geometries) {
params.geometries = geometries;
esriConfig.defaults.geometryService.buffer(params, showBuffer);
});
} else {
params.geometries = [normalizedGeometry];
esriConfig.defaults.geometryService.buffer(params, showBuffer);
}
});
}
function showBuffer(bufferedGeometries) {
var symbol = new SimpleFillSymbol(
SimpleFillSymbol.STYLE_SOLID,
new SimpleLineSymbol(
SimpleLineSymbol.STYLE_SOLID,
new Color([255,0,0,0.65]), 2
),
new Color([255,0,0,0.35])
);
array.forEach(bufferedGeometries, function(geometry) {
var graphic = new Graphic(geometry, symbol);
map.graphics.add(graphic);
});
var query = new Query();
query.geometry = bufferedGeometries.getExtent();
//use a fast bounding box query. will only go to the server if bounding box is outside of the visible map
featureLayer.queryFeatures(query, selectInBuffer);
}
var layer = new esri.layers.ArcGISDynamicMapServiceLayer("http://bccarct1:6080/arcgis/rest/services/CAPITAL_IMPROVEMENT_PROJECTS/crime/MapServer");
var featureLayer = new FeatureLayer("http://bccarct1:6080/arcgis/rest/services/CAPITAL_IMPROVEMENT_PROJECTS/crime/MapServer/0",{
outFields: ["Offense","Report_Dat","Street_Num", "Street_Nam", "Suffix", "City", "State", "Zip_Code"]
});
map.addLayer(featureLayer);
// selection symbol used to draw the selected census block points within the buffer polygon
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])
);
featureLayer.setSelectionSymbol(symbol);
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;
}
});
</script>
</head>
<body class="claro">
<div data-dojo-type="dijit/layout/BorderContainer"
data-dojo-props="gutters:'true', design:'sidebar'"
style="width:100%;height:100%;">
<div id="map"
data-dojo-type="dijit/layout/ContentPane"
data-dojo-props="region:'center'">
</div>
<div id="leftPane"
data-dojo-type="dijit/layout/ContentPane"
data-dojo-props="region:'left'">
<div class="details">Pick a tool and draw on the map. The drawn graphic will be buffered based on the specified parameters.</div>
<button type="button" class="tool" id="line">Line</button>
<button type="button" class="tool" id="polyline">Polyline</button>
<button type="button" class="tool" id="freehandpolyline">Freehand Polyline</button>
<br/>
<button type="button" class="tool" id="polygon">Polygon</button>
<button type="button" class="tool" id="freehandpolygon">Freehand Polygon</button>
<br/><hr />
<div><b>Buffer Parameters</b></div>
Distance: <input type="text" id="distance" size="5" value="660" />
<select id="unit" style="width:100px;">
<option value="UNIT_FOOT">Feet</option>
<option value="UNIT_STATUTE_MILE">Miles</option>
<option value="UNIT_KILOMETER">Kilometers</option>
<option value="UNIT_METER">Meters</option>
<option value="UNIT_NAUTICAL_MILE">Nautical Miles</option>
<option value="UNIT_US_NAUTICAL_MILE">US Nautical Miles</option>
<option value="UNIT_DEGREE">Degrees</option>
</select><br />
<button type="button" id="clearGraphics" type="button">Clear Graphics</button>
</div>
</div>
</body>
</html>
谢谢
答案 0 :(得分：0)
您可以尝试向查询添加距离和单位以获取缓冲区中的点。做这样的事情：
var query = new Query();
query.distance = [ dom.byId("distance").value ];
query.units = GeometryService[dom.byId("unit").value];
featureLayer.queryFeatures(query, selectInBuffer);