1.仅仅对官网中Draw工具的一个例子进行分析
以上是实现的东西
2.全部代码
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">
<title>Shapes and Symbols</title>
<link rel="stylesheet" href="https://js.arcgis.com/3.26/esri/css/esri.css">
<style>
#info {
top: 20px;
color: #444;
height: auto;
font-family: arial;
right: 20px;
margin: 5px;
padding: 10px;
position: absolute;
width: 115px;
z-index: 40;
border: solid 2px #666;
border-radius: 4px;
background-color: #fff;
}
html, body, #mapDiv {
padding:0;
margin:0;
height:100%;
}
button {
display: block;
}
</style>
<script src="https://js.arcgis.com/3.26/"></script>
<script>
var map, tb;
require([
"esri/map", "esri/toolbars/draw",
"esri/symbols/SimpleMarkerSymbol", "esri/symbols/SimpleLineSymbol",
"esri/symbols/PictureFillSymbol", "esri/symbols/CartographicLineSymbol",
"esri/graphic",
"esri/Color", "dojo/dom", "dojo/on", "dojo/domReady!"
], function(
Map, Draw,
SimpleMarkerSymbol, SimpleLineSymbol,
PictureFillSymbol, CartographicLineSymbol,
Graphic,
Color, dom, on
) {
map = new Map("mapDiv", {
basemap: "streets",
center: [-25.312, 34.307],
zoom: 3
});
map.on("load", initToolbar);
// markerSymbol is used for point and multipoint, see http://raphaeljs.com/icons/#talkq for more examples
var markerSymbol = new SimpleMarkerSymbol();
markerSymbol.setPath("M16,4.938c-7.732,0-14,4.701-14,10.5c0,1.981,0.741,3.833,2.016,5.414L2,25.272l5.613-1.44c2.339,1.316,5.237,2.106,8.387,2.106c7.732,0,14-4.701,14-10.5S23.732,4.938,16,4.938zM16.868,21.375h-1.969v-1.889h1.969V21.375zM16.772,18.094h-1.777l-0.176-8.083h2.113L16.772,18.094z");
markerSymbol.setColor(new Color("#00FFFF"));
// lineSymbol used for freehand polyline, polyline and line.
var lineSymbol = new CartographicLineSymbol(
CartographicLineSymbol.STYLE_SOLID,
new Color([255,0,0]), 10,
CartographicLineSymbol.CAP_ROUND,
CartographicLineSymbol.JOIN_MITER, 5
);
// fill symbol used for extent, polygon and freehand polygon, use a picture fill symbol
// the images folder contains additional fill images, other options: sand.png, swamp.png or stiple.png
var fillSymbol = new PictureFillSymbol(
"images/mangrove.png",
new SimpleLineSymbol(
SimpleLineSymbol.STYLE_SOLID,
new Color('#000'),
1
),
42,
42
);
function initToolbar() {
tb = new Draw(map);
tb.on("draw-complete", addGraphic);
// event delegation so a click handler is not
// needed for each individual button
on(dom.byId("info"), "click", function(evt) {
if ( evt.target.id === "info" ) {
return;
}
var tool = evt.target.id.toLowerCase();
map.disableMapNavigation();
tb.activate(tool);
});
}
function addGraphic(evt) {
//deactivate the toolbar and clear existing graphics
tb.deactivate();
map.enableMapNavigation();
// figure out which symbol to use
var symbol;
if ( evt.geometry.type === "point" || evt.geometry.type === "multipoint") {
symbol = markerSymbol;
} else if ( evt.geometry.type === "line" || evt.geometry.type === "polyline") {
symbol = lineSymbol;
}
else {
symbol = fillSymbol;
}
map.graphics.add(new Graphic(evt.geometry, symbol));
}
});
</script>
</head>
<body>
<div id="info">
<div>Select a shape then draw on map to add graphic</div>
<button id="Point">Point</button>
<button id="Multipoint">Multipoint</button>
<button id="Line">Line</button>
<button id="Polyline">Polyline</button>
<button id="FreehandPolyline">Freehand Polyline</button>
<button id="Triangle">Triangle</button>
<button id="Extent">Rectangle</button>
<button id="Circle">Circle</button>
<button id="Ellipse">Ellipse</button>
<button id="Polygon">Polygon</button>
<button id="FreehandPolygon">Freehand Polygon</button>
</div>
<div id="mapDiv"></div>
</body>
</html>
3.进行分析
此次主要是对脚本进行分析
3.1 请求模块
<script src="https://js.arcgis.com/3.26/"></script>
以上是引入esri api的网上模块url,可以下载离线包并调用。
require([
"esri/map", "esri/toolbars/draw",
"esri/symbols/SimpleMarkerSymbol", "esri/symbols/SimpleLineSymbol",
"esri/symbols/PictureFillSymbol", "esri/symbols/CartographicLineSymbol",
"esri/graphic",
"esri/Color", "dojo/dom", "dojo/on", "dojo/domReady!"
], function(
Map, Draw,
SimpleMarkerSymbol, SimpleLineSymbol,
PictureFillSymbol, CartographicLineSymbol,
Graphic,
Color, dom, on
){
……}
一些基础的模块:map是载入地图用的;draw是为了new个画图工具类;SimpleMarkerSymbol是点符号;SimpleLineSymbol线符号;PictureFillSymbol填充符号(为了在图层上画多边形);CartographicLineSymbol实线或者虚线(像SimpleLineSymbol,可定制);graphic用于新建图层,一个图层可以包含几何图形,符号,属性,属性框等;Color是定义符号颜色用;dom是操作节点;on是用于绑定事件;domReady!是用于等待将require的模块全加载后再运行脚本的,最好写上,不是功能模块。
3.2 载入地图
map = new Map("mapDiv", {
basemap: "streets",
center: [-25.312, 34.307],
zoom: 3
});
map.on("load", initToolbar);
代码分析:new一个map图层,容器的id是“mapDiv”(在body标签内先写好),底图是“streets”,也可以通过其它方式添加底图,这里就不细讲了。center: [-25.312, 34.307]是定义了中心点坐标,zoom: 3即是地图显示等级;map.on("load", initToolbar);就是地图绑定事件,在加载事件发生的时候,运行initToolbar。
3.3 定义initToolbar功能
3.3.1 定义符号
Draw工具在绘制符号的时候,应该填充一些符号。所以首先应该定义好符号的类型。比如点、线、面对应的符号类型都有所不同的。
定义点符号:
var markerSymbol = new SimpleMarkerSymbol();
markerSymbol.setPath("M16,4.938c-7.732,0-14,4.701-14,10.5c0,1.981,0.741,3.833,2.016,5.414L2,25.272l5.613-1.44c2.339,1.316,5.237,2.106,8.387,2.106c7.732,0,14-4.701,14-10.5S23.732,4.938,16,4.938zM16.868,21.375h-1.969v-1.889h1.969V21.375zM16.772,18.094h-1.777l-0.176-8.083h2.113L16.772,18.094z");
markerSymbol.setColor(new Color("#00FFFF"));
以上是new一个点符号,markerSymbol.setPath是将一个点符号的SVG路径传递过来,以求定制点符号的样式;如果没啥特殊需求的话,直接markerSymbol.STYLE_CIRCLE;就可以了,这是让点符号定义成一个圆。
定义线符号:
var lineSymbol = new CartographicLineSymbol(
CartographicLineSymbol.STYLE_SOLID, //实线
new Color([255,0,0]), //颜色
10, //粗细
CartographicLineSymbol.CAP_ROUND, //线在终点处是圆的(还有其它口味,可以自行查)
CartographicLineSymbol.JOIN_MITER, //折线处表现的形式(有多种口味,可自查)
5 //两条线连接的阈值
);
定义面符号:
var fillSymbol = new PictureFillSymbol(
"images/mangrove.png", //填充符号内部图像
// 因为这是面符号,肯定有边框,边框就是线符号鸭
//就得定义个线符号
new SimpleLineSymbol(
SimpleLineSymbol.STYLE_SOLID,
new Color('#000'),
1
),
42, //内部填充图像宽度(像素为单位)
42 //内部填充图像长度(像素为单位)
);
图片可以随意定义,一下是小生的一个例图:
此生无悔入东方!来世愿生幻想乡! 不好意思,跑题了_(:з」∠)_。。
3.3.2 定义initToolbar函数
function initToolbar() {
tb = new Draw(map); //new一个画笔工具,并指定关联的容器
tb.on("draw-complete", addGraphic); //绑定draw-complete事件,画笔画好后,
//执行addGraphic函数
//点击info的DIV时,触发回调函数
on(dom.byId("info"), "click", function(evt) {
//如果点击的只是框,那就啥也不做
if ( evt.target.id === "info" ) {
return;
}
//如果是按钮,就获取点击按钮的类型
var tool = evt.target.id.toLowerCase();
//让地图导航功能禁用
map.disableMapNavigation();
//激活按钮对应的画图工具
tb.activate(tool);
});
}
3.3.3 定义addGraphic函数
function addGraphic(evt) {
//停止Draw工具
tb.deactivate();
//恢复地图的导航功能
map.enableMapNavigation();
// 以下是根据Draw出来的符号,通过判断类型,加入不同的符号
var symbol;
if ( evt.geometry.type === "point" || evt.geometry.type === "multipoint") {
symbol = markerSymbol;
} else if ( evt.geometry.type === "line" || evt.geometry.type === "polyline") {
symbol = lineSymbol;
}
else {
symbol = fillSymbol;
}
//将利用符号将定义的图形画出来,并加入地图容器中
map.graphics.add(new Graphic(evt.geometry, symbol));
}