问如何在Esri GIS Maps中高亮显示或勾勒出一个地区(城市)

EN

require([  
"esri/geometry/Point", 
"esri/symbols/SimpleMarkerSymbol",  
"dojo/_base/Color", 
"esri/graphic", ... ], 
function(Point, SimpleMarkerSymbol, Color, Graphic) {  

// assuming cities is an array of city objects with lat and lon attributes
var cities = /*get your array of city locations*/

// Define a symbol to use
var citySymbol = new SimpleMarkerSymbol().setStyle(SimpleMarkerSymbol.STYLE_SQUARE).setColor(new Color([255,0,0,0.5]));

// Loop through each city   
for (n = 0; n < cities.length; n++) {

    // Create a point geometry
    var pt = new Point(cities[n].x,cities[n].y,map.spatialReference)

    // Create a graphic using the point and symbol
    var graphic = new Graphic(pt,citySymbol);

    // add the graphic to the map
    map.graphics.add(graphic);

}