ArcGIS JSAPI 学习教程 - ArcGIS Maps SDK for JavaScript - 框选显示高亮对象
在研究 ArcGIS JSAPI RenderNode 高亮（highlights）FBO 的时候，实现了一下框选高亮几何对象，这里分享一下。
本文包括核心代码、完整代码以及在线示例。
核心代码
实际上，就是通过标绘工具，创建矩形标绘，在判断矩形相交，然后高亮相交的几何对象。
javascript
// 监听标绘完成事件
sketchViewModel.on("create", async (event) => {
if (event.state === "complete") {
const queryGeometry = event.graphic.geometry;
if (this.campusLayerView) {
// 获取矩形内几何对象
const results = await this.campusLayerView.queryFeatures({
geometry: queryGeometry,
});
// 设置高亮
results.features.forEach((feature) => {
this.highlights.push(this.campusLayerView.highlight([feature.attributes.OID]));
})
}
}
});完整代码：
html
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<title>框选显示高亮对象 | Sample | ArcGIS Maps SDK for JavaScript 4.29</title>
<script type="module" src="/arcgis_api/calcite-components/2.8.1/calcite.esm.js"></script>
<link rel="stylesheet" type="text/css" href="/arcgis_api/calcite-components/2.8.1/calcite.css" />
<link rel="stylesheet" href="/arcgis_api/4.29/esri/themes/light/main.css" />
<script src="/arcgis_api/4.29/init.js"></script>
<script>
var _hmt = _hmt || [];
(function () {
var hm = document.createElement("script");
hm.src = "https://hm.baidu.com/hm.js?f80a36f14f8a73bb0f82e0fdbcee3058";
var s = document.getElementsByTagName("script")[0];
s.parentNode.insertBefore(hm, s);
})();
</script>
<script>
require([
"esri/WebScene",
"esri/views/SceneView",
"esri/rest/support/Query",
"esri/widgets/Legend",
"esri/core/reactiveUtils",
"esri/views/3d/webgl/RenderNode",
"esri/layers/GraphicsLayer",
"esri/widgets/Sketch/SketchViewModel",
],
(
WebScene,
SceneView,
Query,
Legend,
reactiveUtils,
RenderNode,
GraphicsLayer,
SketchViewModel,
) => {
// 使用官方资源
const webscene = new WebScene({
portalItem: {
// autocasts as new PortalItem()
id: "fbbc829fa7d342e7ae8d18c54a5eab37"
}
});
// Create a view and set the highlight options
const view = new SceneView({
container: "viewDiv",
map: webscene,
popup: {
dockOptions: {
buttonEnabled: false
}
},
qualityProfile: "high",
environment: {
lighting: {
directShadowsEnabled: true
}
},
// 设置默认高亮参数
highlightOptions: {
haloColor: [255, 38, 150],
color: [255, 255, 255],
fillOpacity: 0.3
}
});
// This variable will store the highlight handle that is used to remove the highlight
this.highlights = [];
// 创建标绘图层
const polygonGraphicsLayer = new GraphicsLayer({
elevationInfo: {
// 注意，这里设置相对于地形，否则会遮挡
mode: 'relative-to-ground'
}
});
view.map.add(polygonGraphicsLayer);
// add the select by rectangle button the view
view.ui.add("select-by-rectangle", "top-left");
const selectButton = document.getElementById("select-by-rectangle");
// 创建标绘工具
const sketchViewModel = new SketchViewModel({
view: view,
layer: polygonGraphicsLayer
});
// 监听矩形标绘事件
selectButton.addEventListener("click", () => {
view.closePopup();
// 标绘矩形
sketchViewModel.create("rectangle");
// 移除上一次操作
polygonGraphicsLayer.removeAll();
// 移除上一次高亮对象
if(this.highlights){
this.highlights.forEach((highlight) => {
highlight.remove();
});
this.highlights = [];
}
});
// 监听标绘完成事件
sketchViewModel.on("create", async (event) => {
if (event.state === "complete") {
const queryGeometry = event.graphic.geometry;
if (this.campusLayerView) {
// 获取矩形内几何对象
const results = await this.campusLayerView.queryFeatures({
geometry: queryGeometry,
});
// 设置高亮
results.features.forEach((feature) => {
this.highlights.push(this.campusLayerView.highlight([feature.attributes.OID]));
})
}
}
});
view.when(() => {
// Get layer from webScene
const campusSceneLayer = webscene.allLayers.filter((elem) => {
return elem.title === "Buildings";
}).items[0];
// Define the attributes which are used in the query
campusSceneLayer.outFields = ["name"];
// Get DOM element where list items will be placed
const container = document.getElementById("buildingsList");
const buildingCount = document.getElementById("buildingCount");
// Highlight is set on the layerView, so we need to detect when the layerView is ready
view.whenLayerView(campusSceneLayer).then((campusLayerView) => {
this.campusLayerView = campusLayerView;
// Wait for the view to finish updating
reactiveUtils.when(() => !view.updating, () => {
// Query the features available for drawing and get the attributes
const query = new Query();
campusLayerView.queryFeatures(query).then((result) => {
// Empty the list DOM element
container.innerHTML = "";
buildingCount.innerHTML = `Currently in view: ${result.features.length} buildings`;
// For each returned feature create a list item and append it to the container
result.features.forEach((feature) => {
const attributes = feature.attributes;
// Create list element
const li = document.createElement("calcite-pick-list-item");
li.setAttribute("label", attributes.name);
li.addEventListener("click", (event) => {
const target = event.target;
const objectId = feature.attributes.OID;
// Create an extent query on the layer view that will return the 3D extent of the feature
const queryExtent = new Query({
objectIds: [objectId]
});
campusLayerView
.queryExtent(queryExtent)
.then((result) => {
// Zoom to the extent of the feature
// Use the expand method to prevent zooming in too close to the feature
if (result.extent) {
view
.goTo(result.extent.expand(4), {
speedFactor: 0.5
})
.catch((error) => {
if (error.name != "AbortError") {
console.error(error);
}
});
}
});
// Remove the previous highlights
if (highlight) {
highlight.remove();
}
// Highlight the feature passing the objectId to the method
highlight = campusLayerView.highlight([objectId]);
});
container.appendChild(li);
});
});
});
});
});
});
</script>
<style>
html,
body,
#viewDiv {
height: 100%;
width: 100%;
margin: 0;
padding: 0;
}
.panel-side {
width: 250px;
position: absolute;
top: 14px;
right: 14px;
bottom: 28px;
color: #323232;
background-color: rgb(255, 255, 255);
box-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
overflow: auto;
z-index: 60;
font-size: 12px;
text-align: center;
}
.panel-side h2 {
padding: 0 20px;
margin: 20px 0;
font-size: 14px;
font-weight: 600;
}
#buildingCount,
h2 {
text-align: center;
}
</style>
</head>
<body>
<div class="panel-side esri-widget">
<h2>Campus buildings</h2>
<p id="buildingCount">Currently in view: 0 buildings</p>
<calcite-panel id="buildingsList">
</calcite-panel>
</div>
<div id="viewDiv"></div>
<div
id="select-by-rectangle"
class="esri-widget esri-widget--button esri-widget esri-interactive"
title="Select features by rectangle"
>
<span class="esri-icon-checkbox-unchecked"></span>
</div>
</body>
</html>
在线示例
ArcGIS Maps SDK for JavaScript 在线示例：框选显示高亮对象