google地图的路线实现代码

<script language="javascript" type="text/javascript"> 
//add by ahuinan 2009-8-17 
//initialize(23.165613663312594,113.35968017578125) 
var map; 
var gdir; 
var marker2; 
var hasMarker = false; 
var hotelLatLng = new GLatLng(<%=initxy %>);//初始化酒店的坐标 
var polyline; 
var points = []; 
points[1] = hotelLatLng; 
function initialize() { 
if (GBrowserIsCompatible()) { 
map = new GMap2(document.getElementById("divMap"), { googleBarOptions: { showOnLoad: true} }); 
gdir = new GDirections(map); 
map.setCenter(hotelLatLng, 9); 
map.addControl(new GOverviewMapControl()); 
map.addControl(new GLargeMapControl()); //加入搜索框 
map.enableGoogleBar(); 
map.enableScrollWheelZoom(); 
//创建酒店的标注，不可拖动 
var hotelMarker = new GMarker(new GLatLng(<%=initxy %>)); 
map.addOverlay(hotelMarker); 
//鼠标左键可以建立一个标记， 
GEvent.addListener(map,"click",function(overlay,latlng,overlaylatlng){ 
if(latlng == null || hasMarker == true){ 
return; 
} 
var greenIcon = new GIcon(G_DEFAULT_ICON); 
greenIcon.image = "../googlemap/green-dot.png"; 
greenIcon.iconSize = new GSize(32,32); 
greenIcon.iconAnchor = new GPoint(16,32); 
greenIcon.shadowSize=new GSize(56,33); 
marker2 = new GMarker(latlng,{draggable: true,icon:greenIcon}); 
map.addOverlay(marker2); 
GEvent.addListener(marker2,"dragend",function(){ 
points[0] = marker2.getLatLng(); 
gdir.loadFromWaypoints(points,{"preserveViewport":true}); 

}) 
GEvent.addListener(gdir, "addoverlay", function(){ 
for (var i=0; i<=gdir.getNumRoutes(); i++){ 
var originalMarker = gdir.getMarker(i); 
map.removeOverlay(originalMarker); 
} 
polyline = gdir.getPolyline(); 

polyline.setStrokeStyle({color:"red",weight:2,opacity:1}); 
// map.addOverlay(polyline); 
}); 
hasMarker = true; 
points[0] = latlng; 
gdir.loadFromWaypoints(points,{"preserveViewport":true}); 
}) 
} 
} 
//按下添加按钮 
function add(){ 
if(points.length == 1){ 
alert("没有线路，终止操作"); 
}else{ 
window.opener.document.getElementById("txtHI_MapMarkDesc").value = window.opener.document.getElementById("txtHI_MapMarkDesc").value+"\n"+document.getElementById("txtName").value+"||||"+document.getElementById("txtType").value+"||||"+points[0]+"\n"; 
window.close(); 
} 
} 
window.onload = function() { 
initialize() 
} 
</script>