我正在使用Google Maps V3来显示一些引脚。我希望能够刷新标记，而不会影响您在地图上的位置或缩放级别。我希望标记每x秒更新一次。
我该怎么做呢？我对jQuery / ajax没有那么多经验。
我的地图的一个工作示例如下。
var locations = [
['some random info here', -37.8139, 144.9634, 1],
['some random info here', 46.0553, 14.5144, 2],
['some random info here', -33.7333, 151.0833, 3],
['some random info here', 27.9798, -81.731, 4], ];
var map = new google.maps.Map(document.getElementById('map_2385853'), {
zoom: 1,
maxZoom: 8,
minZoom: 1,
streetViewControl: false,
center: new google.maps.LatLng(40, 0),
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var infowindow = new google.maps.InfoWindow();
var marker, i;
for (i = 0; i < locations.length; i++) {
marker = new google.maps.Marker({
position: new google.maps.LatLng(locations[i][1], locations[i][2]),
map: map
});
google.maps.event.addListener(marker, 'click', (function(marker, i) {
return function() {
infowindow.setContent(locations[i][0]);
infowindow.open(map, marker);
}
})(marker, i));
}
谢谢
答案 0 :(得分：22)
好的，我有一些工作 - 很大程度上是对原始代码的大量重构 - 你会认识到各种各样的块。
$(function() {
var locations = {};//A repository for markers (and the data from which they were constructed).
//initial dataset for markers
var locs = {
1: { info:'11111. Some random info here', lat:-37.8139, lng:144.9634 },
2: { info:'22222. Some random info here', lat:46.0553, lng:14.5144 },
3: { info:'33333. Some random info here', lat:-33.7333, lng:151.0833 },
4: { info:'44444. Some random info here', lat:27.9798, lng:-81.731 }
};
var map = new google.maps.Map(document.getElementById('map_2385853'), {
zoom: 1,
maxZoom: 8,
minZoom: 1,
streetViewControl: false,
center: new google.maps.LatLng(40, 0),
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var infowindow = new google.maps.InfoWindow();
var auto_remove = true;//When true, markers for all unreported locs will be removed.
function setMarkers(locObj) {
if(auto_remove) {
//Remove markers for all unreported locs, and the corrsponding locations entry.
$.each(locations, function(key) {
if(!locObj[key]) {
if(locations[key].marker) {
locations[key].marker.setMap(null);
}
delete locations[key];
}
});
}
$.each(locObj, function(key, loc) {
if(!locations[key] && loc.lat!==undefined && loc.lng!==undefined) {
//Marker has not yet been made (and there's enough data to create one).
//Create marker
loc.marker = new google.maps.Marker({
position: new google.maps.LatLng(loc.lat, loc.lng),
map: map
});
//Attach click listener to marker
google.maps.event.addListener(loc.marker, 'click', (function(key) {
return function() {
infowindow.setContent(locations[key].info);
infowindow.open(map, locations[key].marker);
}
})(key));
//Remember loc in the `locations` so its info can be displayed and so its marker can be deleted.
locations[key] = loc;
}
else if(locations[key] && loc.remove) {
//Remove marker from map
if(locations[key].marker) {
locations[key].marker.setMap(null);
}
//Remove element from `locations`
delete locations[key];
}
else if(locations[key]) {
//Update the previous data object with the latest data.
$.extend(locations[key], loc);
if(loc.lat!==undefined && loc.lng!==undefined) {
//Update marker position (maybe not necessary but doesn't hurt).
locations[key].marker.setPosition(
new google.maps.LatLng(loc.lat, loc.lng)
);
}
//locations[key].info looks after itself.
}
});
}
var ajaxObj = {//Object to save cluttering the namespace.
options: {
url: "........",//The resource that delivers loc data.
dataType: "json"//The type of data tp be returned by the server.
},
delay: 10000,//(milliseconds) the interval between successive gets.
errorCount: 0,//running total of ajax errors.
errorThreshold: 5,//the number of ajax errors beyond which the get cycle should cease.
ticker: null,//setTimeout reference - allows the get cycle to be cancelled with clearTimeout(ajaxObj.ticker);
get: function() { //a function which initiates
if(ajaxObj.errorCount < ajaxObj.errorThreshold) {
ajaxObj.ticker = setTimeout(getMarkerData, ajaxObj.delay);
}
},
fail: function(jqXHR, textStatus, errorThrown) {
console.log(errorThrown);
ajaxObj.errorCount++;
}
};
//Ajax master routine
function getMarkerData() {
$.ajax(ajaxObj.options)
.done(setMarkers) //fires when ajax returns successfully
.fail(ajaxObj.fail) //fires when an ajax error occurs
.always(ajaxObj.get); //fires after ajax success or ajax error
}
setMarkers(locs);//Create markers from the initial dataset served with the document.
//ajaxObj.get();//Start the get cycle.
// *******************
//test: simulated ajax
/*
var testLocs = {
1: { info:'1. New Random info and new position', lat:-37, lng:124.9634 },//update info and position and
2: { lat:70, lng:14.5144 },//update position
3: { info:'3. New Random info' },//update info
4: { remove: true },//remove marker
5: { info:'55555. Added', lat:-37, lng:0 }//add new marker
};
setTimeout(function() {
setMarkers(testLocs);
}, ajaxObj.delay);
*/
// *******************
});
在代码的底部，您将找到testLocs数据集，演示在应用初始数据集后添加/删除/更新标记的可能性范围。
我没有完全测试过ajax，但已使用testLocs数据集对其进行了模拟。
参见 DEMO
10秒后，将应用testLocs，您将看到标记的各种更改（以及infowindow中显示的信息）。请特别注意，更新数据不需要完整 - 只需指定更改。
您需要安排服务器：
locs示例构建初始数据集。testLocs示例的一般格式返回JSON编码的数据集。我已经包含了获取新数据集所需的所有客户端代码。您所需要做的就是：
url: "........",行以指向服务器端脚本，例如url: "get_markers.php"。ajaxObj.get();来激活循环ajax进程。我添加了一个名为auto_remove的布尔“行为开关”。设置为true时，将运行一小段附加代码块，从而导致删除未报告的loc的所有标记。
这将允许您在每次迭代时报告所有活动标记。删除将自动进行，无需主动命令。
响应{ remove: true }的代码仍然存在，因此（如果auto_remove设置为false）删除可以明确命令，如果您需要这样做。
更新了 DEMO
PHP脚本应该构建以下形式的数组：
<%php
$testLocs = array(
'loc1' => array( 'info' => '1. New Random info and new position', 'lat' => 0, 'lng' => 144.9634 ),
'loc2' => array( 'lat' => 0, 'lng' => 14.5144 ),
'loc3' => array( 'info' => '3. New Random info' ),
'loc5' => array( 'info' => '55555. Added', 'lat' => 0, 'lng' => 60 )
);
echo json_encode($testLocs);
exit();
%>
我不确定PHP是否会处理数字键。如果没有，那么尝试字符串，'1'，'2'等。为所有键提供字母前缀可能是最安全的，例如。 'loc1'，'loc2'等。无论您选择做什么，请确保javascript locs对象中的键具有相同的类型和组成。