❝
注:当前使用的是 ol 9.2.4 版本,天地图使用的
key
请到天地图官网申请,并替换为自己的key
图层资源目录是查看WebGIS
系统数据资源的表现方式,在WebGIS
开发中具有重要意义,通过图层资源目录可清晰查看系统资源以及组织结构,方便查找和查看。 图层控制就是实现图层资源的添加和移除,具体实现方式为当勾选图层复选框时添加图层,去除复选框时移除图层。
1. 创建图层资源目录
在开发工具中创建layer.json
文件,编写layerJSON
图层资源结构。根据图层属性,主要分为天地图、互联网地图以及ArcGIS
地图三大类。示例中的图层资源都是网络公开服务,可以根据自己需要进行添加和移除。
ini
layerJSON = [
{
"title": "天地图",
"id": "1",
"value": "TDT",
"checked": false,
"spread": true,
"disabled": false,
"children": [
{
"title": "天地图矢量",
"url": "http://t0.tianditu.com/DataServer?T=vec_w&x={x}&y={y}&l={z}&tk=",
"id": "11",
"value": "vec_w",
"layerName": "tdtVec",
"checked": false,
"spread": true,
},
{
"title": "天地图影像",
"url": "http://t0.tianditu.com/DataServer?T=img_w&x={x}&y={y}&l={z}&tk=",
"id": "12",
"value": "img_w",
"layerName": "tdtImg",
"checked": false,
"spread": true,
},
{
"title": "天地图注记",
"url": "http://t0.tianditu.com/DataServer?T=cva_w&x={x}&y={y}&l={z}&tk=",
"id": "13",
"value": "cva_w",
"layerName": "tdtCva",
"checked": false,
"spread": false,
}
]
},
{
"title": "互联网地图",
"id": "2",
"value": "net_map",
"checked": false,
"spread": false,
"disabled": false,
"children": [
{
"title": "百度矢量",
"url": "",
"id": "2.2",
"value": "bd",
"checked": false,
"layerName": "bdLayer",
},
{
"title": "高德地图",
"url": "http://wprd0{1-4}.is.autonavi.com/appmaptile?lang=zh_cn&size=1&style=7&x={x}&y={y}&z={z}",
"id": "2.3",
"value": "gd",
"checked": false,
"layerName": "gdLayer",
}
]
},
{
"title": "ArcGIS",
"id": "4",
"value": "ArcGIS",
"checked": false,
"layerName": "arcgisLayer",
"spread": true,
"disabled": false,
"children": [
{
"title": "世界地图",
"id": "4.1",
"value": "arcgisWorld",
"url": "https://sampleserver5.arcgisonline.com/arcgis/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}",
"checked": false,
"layerName": "arcgisWorld",
},
{
"title": "卫星影像",
"id": "4.2",
"value": "arcgisImg",
"url": "https://services.arcgisonline.com/arcgis/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}",
"checked": false,
"layerName": "arcgisImg",
}
]
}
]
2. 创建图层加载方法
在开发工具中创建layer.js
文件,编写加载百度地图、天地图、ArcGIS
地图图层方法以及移除图层方法等。加载图层方法只需要传入地图对象和服务地址。移除图层方法是根据layerName
图层名进行移除,但是layerName
是自定义属性,需要在加载图层时通过layer.set("name","")
或者layer.setProperties({"name":""})
进行设置。在移除图层时,需要获取图层名,可以通过layer.get("name")
或者layer.getProperties()
进行获取。
php
/**
* 添加百度地图
* @param map:地图对象
*/
function addBdLayer(map) {
// 百度地图参数
const resolutions = [];
for (let z = 0; z < 19; ++z) {
resolutions[z] = Math.pow(2, 18 - z);
}
let tilegrid = new ol.tilegrid.TileGrid({
origin: [0, 0],
resolutions: resolutions
});
let source = new ol.source.TileImage({
projection: projection,
tileGrid: tilegrid,
tileUrlFunction: function (tileCoord, pixelRatio, proj) {
if (!tileCoord) {
return "";
}
var z = tileCoord[0];
var x = tileCoord[1];
// var y = tileCoord[2];
var y = -tileCoord[2] - 1;
if (x < 0) {
x = "M" + (-x);
}
if (y < 0) {
y = "M" + (-y);
}
return "http://online3.map.bdimg.com/onlinelabel/?qt=tile&x=" + x + "&y=" + y + "&z=" + z +
"&styles=pl&udt=20151021&scaler=2&p=1"
},
crossOrigin: 'anonymous'
})
let layer = new ol.layer.Tile({
source: source
})
layer.set("name", "bdLayer")
map.addLayer(layer);
}
/**
* 加载高德地图
* @param map:地图对象
* @param url:地图服务地址
*/
function addGdLayer(map, url) {
const gaodeLayer = new ol.layer.Tile({
source: new ol.source.XYZ({
title: "高德地图",
url: url
})
})
gaodeLayer.set("name", "gdLayer")
map.addLayer(gaodeLayer)
}
/**
* 加载天地图影像
* @param map:地图对象
* @param url:地图服务地址
*/
function addTDTImgLayer(map, url) {
const TDTImgLayer = new ol.layer.Tile({
title: "天地图影像图层",
source: new ol.source.XYZ({
url: url,
attibutions: "天地图影像",
crossOrigin: "anoymous",
wrapX: false
})
})
TDTImgLayer.set("name", "tdtImg")
map.addLayer(TDTImgLayer)
}
/**
* 加载天地图矢量
* @param map:地图对象
* @param url:地图服务地址
*/
function addTDTVecLayer(map, url) {
const TDTVecLayer = new ol.layer.Tile({
title: "天地图矢量图层",
source: new ol.source.XYZ({
url: url,
attibutions: "天地图矢量",
crossOrigin: "anoymous",
wrapX: false
})
})
TDTVecLayer.set("name", "tdtVec")
map.addLayer(TDTVecLayer)
}
/**
* 加载天地图注记
* @param map:地图对象
* @param url:地图服务地址
*/
function addTDTCvaLayer(map, url) {
const TDTCvaLayer = new ol.layer.Tile({
title: "天地图注记图层",
source: new ol.source.XYZ({
url: url,
attibutions: "天地图注记",
crossOrigin: "anoymous",
wrapX: false
})
})
TDTCvaLayer.set("name", "tdtCva")
map.addLayer(TDTCvaLayer)
}
/**
* 加载ArcGIS影像
* @param map:地图对象
* @param url:地图服务地址
*/
function addArcGISImg(map, url) {
let source = new ol.source.XYZ({
url: url,
wrapX: true,
crossOrigin: 'anonymous'
})
let layer = new ol.layer.Tile({
source: source
})
layer.set("name", "arcgisImg")
map.addLayer(layer);
}
/**
* 加载ArcGIS世界地图
* @param map:地图对象
* @param url:地图服务地址
*/
function addArcGISWorld(map, url) {
let source = new ol.source.XYZ({
url: url,
wrapX: true,
crossOrigin: 'anonymous'
})
let layer = new ol.layer.Tile({
source: source
})
layer.set("name", "arcgisWorld")
map.addLayer(layer);
}
/**
* 移除目标图层
* @param layerName:图层名称
*/
function removeLayerByName(layerName) {
const layers = map.getLayers().getArray()
layers.forEach(layer => {
if (layer.get('name') === layerName) map.removeLayer(layer)
});
}
3. 图层资源控制
监听oncheck
事件,通过checked
属性判断是否添加或移除图层。
go
layui.use(function () {
var tree = layui.tree;
var layer = layui.layer;
var util = layui.util;
// 渲染
tree.render({
elem: '#layer-tree',
id: "layer-tree",
data: layerJSON,
showCheckbox: true,
oncheck: obj => {
console.log(obj)
// obj.checked // 是否被选中
// obj.data // 数据项
const layerObj = obj.data
if (obj.checked) {
switch (layerObj.value) {
case "bd":
addBdLayer(map)
break
case "gd":
addGdLayer(map, layerObj.url)
break
case "vec_w":
addTDTVecLayer(map, layerObj.url)
break
case "img_w":
addTDTImgLayer(map, layerObj.url)
break
case "cva_w":
addTDTCvaLayer(map, layerObj.url)
break
case "arcgisWorld":
addArcGISWorld(map, layerObj.url)
break
case "arcgisImg":
addArcGISImg(map, layerObj.url)
break
}
} else {
const layerObj = obj.data
removeLayerByName(layerObj.layerName)
}
}
})
tree.reload("layer-tree", {
data: layerJSON
})
})
4. 参考资料
服务资源:www.jianshu.com/p/e9123e2cd...layui:layui.dev/docs/2/tree...
5. 完整代码
其中libs
文件夹下的包需要更换为自己下载的本地包或者引用在线资源。
xml
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>图层控制</title>
<meta charset="utf-8" />
<script src="../../libs/js/jquery-2.1.1.min.js"></script>
<script src="../../libs/proj4.js"></script>
<script src="../../js/ol9.2.4.js"></script>
<link rel="stylesheet" href="../../css/ol9.2.4.css">
<script src="../../libs/layui/layui.js"></script>
<link rel="stylesheet" href="../../libs/layui/css/layui.css">
<script src="./layerJSON.json"></script>
<script src="./layer.js"></script>
<style>
* {
padding: 0;
margin: 0;
font-size: 14px;
font-family: '微软雅黑';
}
html,
body {
width: 100%;
height: 100%;
}
#map {
position: absolute;
top: 0;
bottom: 0;
width: 100%;
}
#layer-container {
position: absolute;
top: 5%;
left: 20px;
width: 15%;
bottom: 5%;
background: #fff;
color: #fff;
border-radius: 2.5px;
border: 1px solid #ddd;
}
.layer-head {
background: #16baaa;
padding: 10px;
}
</style>
</head>
<body>
<div id="map" title="地图显示"></div>
<div id="layer-container">
<h2 class="layer-head">图层资源</h2>
<ul id="layer-tree"></ul>
</div>
</body>
</html>
<script>
proj4.defs('EPSG:4008', '+proj=longlat +ellps=clrk66 +no_defs')
proj4.defs('BD-MC', '+proj=merc +lon_0=0 +units=m +ellps=clrk66 +no_defs')
ol.proj.proj4.register(proj4)
//地图投影坐标系
const projection = ol.proj.get('EPSG:3857');
//==============================================================================//
//============================天地图服务参数简单介绍==============================//
//================================vec:矢量图层==================================//
//================================img:影像图层==================================//
//================================cva:注记图层==================================//
//======================其中:_c表示经纬度投影,_w表示球面墨卡托投影================//
//==============================================================================//
const TDTImgLayer = new ol.layer.Tile({
title: "天地图影像图层",
source: new ol.source.XYZ({
url: "http://t0.tianditu.com/DataServer?T=img_w&x={x}&y={y}&l={z}&tk=2a890fe711a79cafebca446a5447cfb2",
attibutions: "天地图注记描述",
crossOrigin: "anoymous",
wrapX: false
})
})
const TDTImgCvaLayer = new ol.layer.Tile({
title: "天地图影像注记图层",
source: new ol.source.XYZ({
url: "http://t0.tianditu.com/DataServer?T=cia_w&x={x}&y={y}&l={z}&tk=2a890fe711a79cafebca446a5447cfb2",
attibutions: "天地图注记描述",
crossOrigin: "anoymous",
wrapX: false
})
})
const map = new ol.Map({
target: "map",
loadTilesWhileInteracting: true,
view: new ol.View({
// center: [104.0635986160487, 30.660919181071225],
// center: [11444274, 12707441],
// center: [11421771, 4288300],
center: ol.proj.transform([116.403414, 39.904091], 'EPSG:4326', 'EPSG:3857'),
zoom: 5,
worldsWrap: false,
minZoom: 1,
maxZoom: 20,
projection: 'EPSG:3857',
}),
layers: [TDTImgLayer, TDTImgCvaLayer],
// 地图默认控件
controls: ol.control.defaults.defaults({
zoom: false,
attribution: true,
rotate: true
})
})
map.on('click', evt => {
console.log(evt.coordinate)
})
layui.use(function () {
var tree = layui.tree;
var layer = layui.layer;
var util = layui.util;
// 渲染
tree.render({
elem: '#layer-tree',
id: "layer-tree",
data: layerJSON,
showCheckbox: true,
oncheck: obj => {
console.log(obj)
// obj.checked // 是否被选中
// obj.data // 数据项
const layerObj = obj.data
if (obj.checked) {
switch (layerObj.value) {
case "bd":
addBdLayer(map)
break
case "gd":
addGdLayer(map, layerObj.url)
break
case "vec_w":
addTDTVecLayer(map, layerObj.url)
break
case "img_w":
addTDTImgLayer(map, layerObj.url)
break
case "cva_w":
addTDTCvaLayer(map, layerObj.url)
break
case "arcgisWorld":
addArcGISWorld(map, layerObj.url)
break
case "arcgisImg":
addArcGISImg(map, layerObj.url)
break
}
} else {
const layerObj = obj.data
removeLayerByName(layerObj.layerName)
}
}
})
tree.reload("layer-tree", {
data: layerJSON
})
})
</script>
❝
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