大家晚上好。现在我正在开发一个GPS定位Web服务器，我正在从GPS卡获取坐标到服务器中的端口嗅探器，它将坐标写入SQL数据库。我遇到的问题是，我不断刷新网页以获取新数据，但是如果用户在刷新时放大或缩小或移动中心，所有这些更改都会丢失。
这是JS片段：
<script>
// functions below
//Make an array with the coordinates from the db
function initialize() {
var posicion= [];
for (var i=0; i< lat.length; i++){
posicion.push(new google.maps.LatLng(lat[i], long[i])); // Add the coordinates
}
var mapOptions = {
zoom: 16,
center: posicion[lat.length-1],
mapTypeId: google.maps.MapTypeId.TERRAIN
};
var map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions); // Render our map within the empty div
var linea = new google.maps.Polyline({
path: posicion,
geodesic: true,
strokeColor: '#FF0000',
strokeOpacity: 1.0,
strokeWeight: 2
});
linea.setMap(map);
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
您必须收听事件"bounds_changed"，然后将结果保存在cookie上。重新加载时，将这些值用作缩放和居中的默认值
google.maps.event.addListener(map, 'bounds_changed', (function () {
var centerTobeSavedOnCookie = map.getCenter();
var zoomTobeSavedOnCookie = map.getZoom();
// save values to cookies
setCookie("gmapDefaultZoom", zoomTobeSavedOnCookie, 1);
setCookie("gmapDefaultCenter", centerTobeSavedOnCookie , 1);
}()));
function setCookie(cname, cvalue, exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires="+d.toUTCString();
document.cookie = cname + "=" + cvalue + "; " + expires;
}
function getCookie(cname) {
var name = cname + "=";
var ca = document.cookie.split(';');
for(var i=0; i<ca.length; i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1);
if (c.indexOf(name) == 0) return c.substring(name.length,c.length);
}
return "";
}