Chandan,
It would just be a matter of knowing the id of the operational layer so that you can use map.removeLayer(layerId); and then adding the selected layer using map.AddLayer.
Here is a sample:
<!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></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; }
#map{
padding:0;
}
</style>
<script src="http://js.arcgis.com/3.14/"></script>
<script>
var map;
var layers = [];
var handle;
require([
"dojo/on",
"esri/map",
"esri/dijit/BasemapGallery",
"esri/arcgis/utils",
"dojo/parser",
"esri/layers/FeatureLayer",
"dojo/store/Memory",
"esri/dijit/util/busyIndicator",
"dijit/layout/BorderContainer",
"dijit/layout/ContentPane",
"dijit/TitlePane",
"dijit/form/ComboBox",
"dojo/domReady!"
], function(
on,
Map,
BasemapGallery,
arcgisUtils,
parser,
FeatureLayer,
Memory,
busyIndicator
) {
parser.parse();
map = new Map("mapDiv", {
basemap: "topo",
center: [-105.255, 40.022],
zoom: 5
});
//add the basemap gallery, in this case we'll display maps from ArcGIS.com including bing maps
var basemapGallery = new BasemapGallery({
showArcGISBasemaps: true,
map: map
}, "basemapGallery");
basemapGallery.startup();
basemapGallery.on("error", function(msg) {
console.log("basemap gallery error: ", msg);
});
var TimeZone = new FeatureLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/WorldTimeZones/MapServer/1", {
id: "OperationalLayer",
mode: FeatureLayer.MODE_SNAPSHOT,
outFields: ["*"]
});
layers.push(TimeZone);
var Regions = new FeatureLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/WorldTimeZones/MapServer/2", {
id: "OperationalLayer",
mode: FeatureLayer.MODE_SNAPSHOT,
outFields: ["*"]
});
layers.push(Regions);
handle = busyIndicator.create(mapDiv);
var store2 = new Memory({data:[]});
dijit.byId("opLayerSelect").set('store',store2);
var data = [];
data.push({id:0, name:"World Time Zones", layer:"TimeZone"});
data.push({id:1, name:"World Regions", layer:"Regions"});
store2 = new Memory({data:data});
dijit.byId("opLayerSelect").set('store',store2);
dijit.byId("opLayerSelect").set('value', data[0].name);
dijit.byId("opLayerSelect").item = dijit.byId("opLayerSelect").store.query({name:"World Time Zones"})[0];
app = {
changeOpLyr: function(){
var store = dijit.byId("opLayerSelect").store;
var cbSelVal = dijit.byId("opLayerSelect").get('value');
var layerIndx = store.query({name:cbSelVal})[0]["id"];
if(map.getLayer("OperationalLayer")){
map.removeLayer(map.getLayer("OperationalLayer"));
}
handle.show();
map.addLayer(layers[layerIndx]);
var lyrEvt = on(layers[layerIndx], "update-end", function(){
handle.hide();
lyrEvt.remove();
});
}
}
});
</script>
</head>
<body class="claro">
<div data-dojo-type="dijit/layout/BorderContainer"
data-dojo-props="design:'headline', gutters:false"
style="width:100%;height:100%;margin:0;">
<div id="header" data-dojo-type="dijit/layout/ContentPane" data-dojo-props="region:'top'" style="overflow:hidden;border:none;border-bottom: 3px solid #CC9900;font-family: Windows;font-size:14pt; color: #FFFFFF;background: #000000; "> Select Operational Layer:
<input id="opLayerSelect" data-dojo-type="dijit/form/ComboBox" onchange="app.changeOpLyr()" data-dojo-props="maxHeight: 200, searchAttr:'name'" />
</div>
<div id="mapDiv"
data-dojo-type="dijit/layout/ContentPane"
data-dojo-props="region:'center'"
style="padding:0;">
<div style="position:absolute; right:20px; top:10px; z-Index:999;">
<div data-dojo-type="dijit/TitlePane"
data-dojo-props="title:'Switch Basemap', closable:false, open:false">
<div data-dojo-type="dijit/layout/ContentPane" style="width:380px; height:280px; overflow:auto;">
<div id="basemapGallery"></div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
