利用百度地图API获取当前位置信息的实例

<script type="text/javascript"> 
var map; 
var gpsPoint; 
var baiduPoint; 
var gpsAddress; 
var baiduAddress; 
var x;
var y;
function getLocation() { 
//根据IP获取城市 
var myCity = new BMap.LocalCity(); 
myCity.get(getCityByIP); 

//获取GPS坐标 
if (navigator.geolocation) { 
navigator.geolocation.getCurrentPosition(showMap, handleError, { enableHighAccuracy: true, maximumAge: 1000 }); 
} else { 
alert("您的浏览器不支持使用HTML 5来获取地理位置服务"); 
} 
} 

function showMap(value) { 
var longitude = value.coords.longitude; 
var latitude = value.coords.latitude; 
map = new BMap.Map("map"); 
x=latitude;
y=longitude;
//alert("坐标经度为：" + latitude + "， 纬度为：" + longitude ); 
gpsPoint = new BMap.Point(longitude, latitude); // 创建点坐标 


//根据坐标逆解析地址 
var geoc = new BMap.Geocoder(); 
geoc.getLocation(gpsPoint, getCityByCoordinate); 

BMap.Convertor.translate(gpsPoint, 0, translateCallback); 
map.enableScrollWheelZoom(true);
} 

translateCallback = function (point) { 
baiduPoint = point; 
map.centerAndZoom(baiduPoint, 18); 
var geoc = new BMap.Geocoder(); 
geoc.getLocation(baiduPoint, getCityByBaiduCoordinate); 
} 

function getCityByCoordinate(rs) { 
gpsAddress = rs.addressComponents; 
var address = "GPS标注：" + gpsAddress.province + "," + gpsAddress.city + "," + gpsAddress.district + "," + gpsAddress.street + "," + gpsAddress.streetNumber; 
var marker = new BMap.Marker(gpsPoint); // 创建标注 
map.addOverlay(marker); // 将标注添加到地图中 
var labelgps = new BMap.Label(address, { offset: new BMap.Size(20, -10) }); 
marker.setLabel(labelgps); //添加GPS标注 
} 

function getCityByBaiduCoordinate(rs) { 
baiduAddress = rs.addressComponents; 
var address = "百度标注：" + baiduAddress.province + "," + baiduAddress.city + "," + baiduAddress.district + "," + baiduAddress.street + "," + baiduAddress.streetNumber; 
var marker = new BMap.Marker(baiduPoint); // 创建标注 
map.addOverlay(marker); // 将标注添加到地图中 
var labelbaidu = new BMap.Label(address, { offset: new BMap.Size(20, -10) }); 
marker.setLabel(labelbaidu); //添加百度标注 
} 

//根据IP获取城市 
function getCityByIP(rs) { 
var cityName = rs.name; 
alert("根据IP定位您所在的城市为:" + cityName); 
} 

function handleError(value) { 
switch (value.code) { 
case 1: 
alert("位置服务被拒绝"); 
break; 
case 2: 
alert("暂时获取不到位置信息"); 
break; 
case 3: 
alert("获取信息超时"); 
break; 
case 4: 
alert("未知错误"); 
break; 
} 
} 

function init() { 
getLocation(); 
} 

window.onload = init; 

</script>