lzugis——Arcgis Server for JavaScript API之自定义InfoWindow（续）
同样的标题后面加了一个括弧，不是为了增减博文数量，而确实是上个功能的完善，标注为续，意思是继续上次的内容，来说说如何自定义InfoWindow。
在上一讲中，实现了InfoWindow的显示，但是并没有实现地图拖动地图InfoWindow随着联动，以及缩放地图InfoWindow随着联动的问题，在本文章中，就上述两个问题提供一个解决思路。
首先，说说拖动地图InfoWindow的联动。拖动地图时，地图并未做缩放，所以只是做一个位置的偏移，因此，定义一个公共变量，记录InfoWindow出来时候的屏幕位置，拖动鼠标时获取鼠标的相对变化，再讲InfoWindow做一相对应的偏移即可：
var beforePoint; //定义InfoWindow出现的上一位置
function leftClick(evt){
infowin.style.display="none";
var strtitle="城市名称"
var strcontent = "****是一座美丽的城市<br><br>****是一座好看的城市<br><br>****是一座富饶的城市<br><br>****是一座漂亮的城市";
title.innerHTML = strtitle;
content.innerHTML = strcontent;
var screenpoint = map.toScreen(evt.mapPoint);
beforeMapPoint = evt.mapPoint;
beforePoint=screenpoint;
showinfowindow(screenpoint.x,screenpoint.y);
}
map.on("pan",function(pan){
var movePoint=pan.delta;
showinfowindow((beforePoint.x+movePoint.x),(beforePoint.y+movePoint.y))
})
map.on("pan-end",function(panend){
var movedelta=panend.delta;
beforePoint.x=beforePoint.x+movedelta.x;
beforePoint.y=beforePoint.y+movedelta.y;
})这样，拖动鼠标，infoWindow会随着鼠标的移动而移动。
接着，我们说说缩放时InfoWindow的联动。缩放时的联动的逻辑是记录InfoWindow首次出现的地图点的坐标，当缩放结束后将首次出现的地图点转换为屏幕坐标，再将其显示出来。
map.on("zoom-end",function(){
var zoomPoint = map.toScreen(beforeMapPoint);
showinfowindow(zoomPoint.x,zoomPoint.y);
beforePoint=zoomPoint;
})
怎么样，很简单吧，下面一并将全的代码附上：
<!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>Feature Layer - display results as an InfoWindow onHover</title>
<link rel="stylesheet" href="http://localhost/arcgis_js_api/library/3.8/3.8/js/dojo/dijit/themes/claro/claro.css">
<link rel="stylesheet" href="http://localhost/arcgis_js_api/library/3.8/3.8/js/dojo/dijit/themes/tundra/tundra.css">
<link rel="stylesheet" href="http://localhost/arcgis_js_api/library/3.8/3.8/js/esri/css/esri.css">
<style>
html, body, #mapDiv
{
padding:0;
margin:0;
height:100%;
font-size:10px;
position: relative;
}
#infowin
{
display:none;
z-index:10000;
}
#close
{
float:right;
padding-top:10px;
font-weight:bold;
font-size:12px;
color:#FFF;
border:#000 1px solid;
height:20px;
width:20px;
text-align:center;
}
#close:hover
{
cursor:pointer;
}
#title
{
background-color:#666;
padding:10px;
font-weight:bold;
font-size:12px;
}
#content
{
padding-left:10px;
padding-top:10px;
background-color:#999;
height:200px;
}
#arrow
{
background-image:url(arrow.png);
height:30px;
}
</style>
<script src="http://js.arcgis.com/3.9/"></script>
<script>
var dmap,infowin,colse,title,content;
var width=400,height=230,offset=50;
var closeInfoWin = function (evt){
infowin=document.getElementById("infowin");
infowin.style.display="none";
};
require([
"esri/map", //地图
"esri/layers/ArcGISTiledMapServiceLayer",
"esri/layers/FeatureLayer",//特征层
"esri/symbols/PictureMarkerSymbol",//图片点符号
"esri/renderers/SimpleRenderer", //简单渲染
"esri/graphic", //图片
"esri/lang",
"dojo/domReady!"
], function(
Map,ArcGISTiledMapServiceLayer,FeatureLayer,PictureMarkerSymbol,SimpleRenderer,esriLang
) {
var beforePoint;
var beforeMapPoint;
var map = new Map("mapDiv", {
logo:false,
center: [106.6854, 35.8364],
zoom: 4,
slider: true
});
var shpServiceURL="**************************************";
var shpTitlelayer=new ArcGISTiledMapServiceLayer(shpServiceURL);
map.addLayer(shpTitlelayer);
//--------------------------------------------------------------------------------------------------------
var featurelayercity = new FeatureLayer("**************************************************", {
mode: FeatureLayer.MODE_SNAPSHOT,
outFields: ["*"]
});
var pmsRed = new PictureMarkerSymbol('../images/location_icon_blue.png', 20, 20).setOffset(0, 15);
//简单渲染
var sr=new SimpleRenderer(pmsRed);
featurelayercity.setRenderer(sr);
map.addLayer(featurelayercity);
dmap=document.getElementById("mapDiv");
infowin = document.getElementById("infowin");
colse = document.getElementById("close");
title = document.getElementById("title");
content = document.getElementById("content");
function showinfowindow(x,y){
infowin.style.left=(x-width/2)+"px";
infowin.style.top=(y-height-offset)+"px";
infowin.style.position="absolute";
infowin.style.width=width+"px";
infowin.style.height=height+"px";
infowin.style.display="block";
};
function leftClick(evt){
infowin.style.display="none";
var strtitle="城市名称"
var strcontent = "****是一座美丽的城市<br><br>****是一座好看的城市<br><br>****是一座富饶的城市<br><br>****是一座漂亮的城市";
title.innerHTML = strtitle;
content.innerHTML = strcontent;
var screenpoint = map.toScreen(evt.mapPoint);
beforeMapPoint = evt.mapPoint;
beforePoint=screenpoint;
showinfowindow(screenpoint.x,screenpoint.y);
}
//鼠标单击
featurelayercity.on("click", leftClick);
map.on("pan",function(pan){
var movePoint=pan.delta;
showinfowindow((beforePoint.x+movePoint.x),(beforePoint.y+movePoint.y))
})
map.on("pan-end",function(panend){
var movedelta=panend.delta;
beforePoint.x=beforePoint.x+movedelta.x;
beforePoint.y=beforePoint.y+movedelta.y;
})
map.on("zoom-end",function(){
var zoomPoint = map.toScreen(beforeMapPoint);
showinfowindow(zoomPoint.x,zoomPoint.y);
beforePoint=zoomPoint;
})
});
</script>
</head>
<body class="tundra">
<div id="mapDiv">
<div id="infowin">
<div id="close" onClick="closeInfoWin()">X</div>
<div id="title"></div>
<div id="content"></div>
<div id="arrow"></div>
</div>
</div>
</body>
</html>