function Location(){};
Location.prototype.getLocation = function(callback){
  var options = {
    enableHighAccuracy: true,
    maximumAge: 1000
  };
  this.callback = Object.prototype.toString.call(callback) =="[object Function]" ?
    callback : 
    function(address){
      alert(address.province + address.city);
      console.log("getocation(callbackFunction) 可獲得定位信息對象");
    };
  var self = this;
  if (navigator.geolocation) {
    //瀏覽器支持geolocation
    navigator.geolocation.getCurrentPosition(function(position){
      //經(jīng)度
      var longitude = position.coords.longitude;
      //緯度
      var latitude = position.coords.latitude;
      self.loadMapApi(longitude,latitude);
    }, self.onError, options);
  } else {
    //瀏覽器不支持geolocation
  }
};
Location.prototype.loadMapApi = function(longitude, latitude){
  var self = this;
  var oHead = document.getElementsByTagName('HEAD').item(0);
  var oScript= document.createElement("script");
  oScript.type = "text/javascript";
  oScript.src="http://api.map.baidu.com/getscript?v=2.0&ak=A396783ee700cfdb9ba1df281ce36862&services=&t=20140930184510";
  oHead.appendChild(oScript);
  oScript.onload = function(date){
    var point = new BMap.Point(longitude, latitude);
    var gc = new BMap.Geocoder();
    gc.getLocation(point, function(rs) {
      var addComp = rs.addressComponents;
      self.callback(addComp);
    });
  }
};
Location.prototype.onError = function(error) {
  switch (error.code) {
    case 1:
      alert("位置服務(wù)被拒絕");
      break;
    case 2:
      alert("暫時獲取不到位置信息");
      break;
    case 3:
      alert("獲取信息超時");
      break;
    case 4:
      alert("未知錯誤");
      break;
  }
};
//調(diào)用
var local = new Location();
local.getLocation(function(res){
  //此處就是返回的地理位置信息
  console.log(res);
})