最近由于项目需求，于是开始了leaflet的学习，leaflet在加载地图上具有自己独特的优势，能够在各种浏览器（包括手机）下面很好的运行，并且具有很多的插件供我们选择。在该教程中， 我们使用了除leaflet之外的额外插件有 esri-leaflet.js(https://esri.github.io/esri-leaflet/)、L.Control.MousePosition.js(https://github.com/ardhi/Leaflet.MousePosition)、【proj4.js与proj4leaflet.js】(https://github.com/kartena/Proj4Leaflet)。
1. 动态图层加载
在加载还图层的时候注意，此时的URL只能是动态图层服务地址，不能具体到某个图层。加载代码如下：
let map = L.map('divclass').setView([28.751407,118.628740],12);
let dynamicLayer = L.esri.dynamicMapLayer({
url:'http://localhost:6080/arcgis/rest/services/js/jsdxt/MapServer/',
opacity: 0.8,
f:'json'
});
map.addLayer(dynamicLayer);
2. 要素图层加载
let map = L.map('divclass').setView([28.751407,118.628740],12);
let featureLayer = L.esri.featureLayer({
url:'http://localhost:6080/arcgis/rest/services/js/tx/MapServer/1/'
});
map.addLayer(featureLayer);
3. 切片图层的加载
our map service must be published using the Web Mercator Auxiliary Sphere tiling scheme (WKID 102100/3857) and the default scale options used by Google Maps, Bing Maps and .Esri Leaflet will not support any other spatial reference for tile layers. 这个摘自官方的一段（https://esri.github.io/esri-leaflet/api-reference/layers/tiled-map-layer.html），大概的意思是当我们使用L.esri.tiledMapLayer的时候，支持WKID为102100/3857的投影地图，既是我们平常使用的web墨卡托投影的地图，其余的地图投影不支持，此时我们就需要用到proj4.js与proj4leaflet.js这两个库来进行自定义投影，具体的投影转换已经各种参数的定义，我们可以通过（https://epsg.io/）这个网站来获取，比如我们搜索4490,如下图，箭头所指的就是我们使用Proj4来进行投影时的定义参数：
当我们获取到了投影参数之后，我们就可以使用L.Proj.CRS来定义一个投影了，具体代码如下：
let tileMapUrl ="http://localhost:6082/arcgis/rest/services/jhzhps/JHJT/MapServer"; let CRS_4490 = new L.Proj.CRS("EPSG:4490", "+proj=longlat +ellps=GRS80 +no_defs", { resolutions: [ 1.40625, 0.703125, 0.3515625, 0.17578125, 0.087890625, 0.0439453125, 0.02197265625, 0.010986328125, 0.0054931640625, 0.00274658203125, 0.001373291015625, 6.866455078125E-4, 3.4332275390625E-4, 1.71661376953125E-4, 8.58306884765625E-5, 4.291534423828125E-5, 2.1457672119140625E-5, 1.0728836059570312E-5, 5.364418029785156E-6, 2.682209064925356E-6, 1.3411045324626732E-6 ], origin: [-179.9999, 90.00016], bounds: L.bounds([117.75370429660006, 26.99449191557761, ], [123.63262097540007, 32.2668788575695]) //这里可以有origin、transformation、scales、resulutions、bounds几个参数提供 //选择，其中scales与resolutions不能同时配置 }); let map = L.map('divclass',{ crs:CRS_4490 }).setView([29.108339,119.647787],13); let tileMapLayer = L.esri.tiledMapLayer({ url:tileMapUrl }); //L.esri.basemapLayer('Gray').addTo(map); map.addLayer(tileMapLayer); L.control.mousePosition({ 'position': 'bottomright' }).addTo(map);
此时，我们已经完成了对切片，要素，动态地图的加载，此代码仅供初学者学习借鉴，整个文件的代码如下图所示：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>leaflet实例</title>
<meta name="renderer" content="webkit">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=0">
<!--添加leaflet样式文件-->
<link rel="stylesheet" type="text/css" href="../floodIndex/leaflet/leaflet.css">
<link rel="stylesheet" type="text/css" href="../floodIndex/css/L.Control.MousePosition.css">
<!--添加leaflet引用-->
<script type="text/javascript" src="../floodIndex/leaflet/leaflet-src.js"></script>
<script type="text/javascript" src="../floodIndex/leaflet/esri-leaflet.js"></script>
<script type="text/javascript" src="../floodIndex/leaflet/L.Control.MousePosition.js"></script>
<script type="text/javascript" src="../floodIndex/leaflet/proj4.js"></script>
<script type="text/javascript" src="../floodIndex/leaflet/proj4leaflet.js"></script>
<style>
html,body{
margin:0;
padding: 0;
}
#divclass{
height:calc(100% - 50px) ;
100%;
background: white;
position: absolute;
}
</style>
</head>
<body>
<div style=" 100%;height: 50px">
</div>
<div id="divclass">
</div>
<script>
//1. 动态图层加载 注意此时的URL只能是动态图层服务地址 只能具体到某个图层
let map = L.map('divclass').setView([28.751407,118.628740],12);
let dynamicLayer = L.esri.dynamicMapLayer({
url:'http://localhost:6080/arcgis/rest/services/js/jsdxt/MapServer/',
opacity: 0.8,
f:'json'
});
map.addLayer(dynamicLayer);
//2.加载要素图层
let map = L.map('divclass').setView([28.751407,118.628740],12);
let featureLayer = L.esri.featureLayer({
url:'http://localhost:6080/arcgis/rest/services/js/tx/MapServer/1/'
});
map.addLayer(featureLayer);
//3.加载切片图层
/**
* Your map service must be published using the Web Mercator Auxiliary Sphere tiling scheme (WKID 102100/3857)
* and the default scale options used by Google Maps, Bing Maps and .
* Esri Leaflet will not support any other spatial reference for tile layers.
*/
let tileMapUrl ="http://localhost:6082/arcgis/rest/services/jhzhps/JHJT/MapServer";
let CRS_4490 = new L.Proj.CRS("EPSG:4490", "+proj=longlat +ellps=GRS80 +no_defs", {
resolutions: [
1.40625,
0.703125,
0.3515625,
0.17578125,
0.087890625,
0.0439453125,
0.02197265625,
0.010986328125,
0.0054931640625,
0.00274658203125,
0.001373291015625,
6.866455078125E-4,
3.4332275390625E-4,
1.71661376953125E-4,
8.58306884765625E-5,
4.291534423828125E-5,
2.1457672119140625E-5,
1.0728836059570312E-5,
5.364418029785156E-6,
2.682209064925356E-6,
1.3411045324626732E-6
],
origin: [-179.9999, 90.00016],
bounds: L.bounds([117.75370429660006, 26.99449191557761, ], [123.63262097540007, 32.2668788575695])
//这里可以有origin、transformation、scales、resulutions、bounds几个参数提供
//选择，其中scales与resolutions不能同时配置
});
let map = L.map('divclass',{
crs:CRS_4490
}).setView([29.108339,119.647787],13);
let tileMapLayer = L.esri.tiledMapLayer({
url:tileMapUrl
});
//L.esri.basemapLayer('Gray').addTo(map);
map.addLayer(tileMapLayer);
L.control.mousePosition({
'position': 'bottomright'
}).addTo(map);
</script>
</body>
</html>