我希望Google地图显示标记带有JSON Feed。但它不起作用。我找不到实际的问题。所以这是我的代码：
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(gdb) p sockfd
$9 = 8
(gdb) p &sockfd
$10 = (int *) 0x611024 <sockfd>
(gdb) p c_snd_id
$11 = "KR", '\000' <repeats 253 times>
(gdb) p &c_snd_id
$12 = (char (*)[256]) 0xfde220 <c_snd_id>
(gdb) p c_rec_id
$13 = "CO", '\000' <repeats 253 times>
(gdb) p &c_rec_id
$14 = (char (*)[256]) 0xfde560 <c_rec_id>
(gdb) p c_timeout_quit
$15 = 20
(gdb) p &c_timeout_quit
$16 = (int *) 0xfde660 <c_timeout_quit>
var map;
// The JSON data
var json = [{
"OpperationErrorMsg":"",
"IsSuccess":true,
"ResultId":1000,
"Timestamp":"2016-10-12T18:00:07.0232702Z",
"Echo":null,
"InSandbox":true,
"DebugMessages":[
],
"MissingDetails":[
],
"ResponseData":[
{
"CallTimeLocal":"2016-10-10T06:28:48.7330000",
"IncidentId":3374,
"IncidentNumber":"HC2016004034",
"CallTime":"2016-10-10T10:28:48.7330000",
"ElapsedSeconds":0,
"Location":"2712 E HANNA AVE",
"BuildingName":null,
"BuildingNumber":null,
"NatureId":6743,
"FirePriorityId":1,
"CoordinateX":-82.429500000000,
"CoordinateY":28.003389000000
},
{
"CallTimeLocal":"2016-10-10T11:28:36.7000000",
"IncidentId":3382,
"IncidentNumber":"HC2016004042",
"CallTime":"2016-10-10T15:28:36.7000000",
"ElapsedSeconds":0,
"Location":"1220 APOLLO BEACH BLVD S",
"BuildingName":"Apollo Beach Marina",
"BuildingNumber":null,
"NatureId":8035,
"FirePriorityId":1,
"CoordinateX":-82.422369000000,
"CoordinateY":27.781254000000
},
{
"CallTimeLocal":"2016-10-10T14:29:59.8830000",
"IncidentId":3387,
"IncidentNumber":"HC2016004047",
"CallTime":"2016-10-10T18:29:59.8830000",
"ElapsedSeconds":0,
"Location":"9600 SHELDONWOOD RD",
"BuildingName":null,
"BuildingNumber":null,
"NatureId":6420,
"FirePriorityId":12,
"CoordinateX":-82.580530000000,
"CoordinateY":28.034779000000
},
{
"CallTimeLocal":"2016-10-10T15:27:37.7270000",
"IncidentId":3389,
"IncidentNumber":"HC2016004049",
"CallTime":"2016-10-10T19:27:37.7270000",
"ElapsedSeconds":0,
"Location":"4691 GALLAGHER RD",
"BuildingName":"Strawberry Crest High School",
"BuildingNumber":null,
"NatureId":7873,
"FirePriorityId":2,
"CoordinateX":-82.236450000000,
"CoordinateY":28.021233000000
}
],
"CurrentStatusData":null
}];
function initialize() {
// Giving the map som options
var mapOptions = {
zoom: 6,
center: new google.maps.LatLng(25.0,-80.0)
};
// Creating the map
map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
// Looping through all the entries from the JSON data
for(var i = 0; i < json.length; i++) {
// Current object
var obj = json[i];
// Adding a new marker for the object
var marker = new google.maps.Marker({
position: new google.maps.LatLng(obj.CoordinateY,obj.CoordinateX),
map: map,
draggable: true,
animation: google.maps.Animation.DROP,
title: obj.BuildingName // this works, giving the marker a title with the correct title
});
// Adding a new info window for the object
var clicker = addClicker(marker, obj.title);
} // end loop
// Adding a new click event listener for the object
function addClicker(marker, content) {
google.maps.event.addListener(marker, 'click', function() {
if (infowindow) {infowindow.close();}
infowindow = new google.maps.InfoWindow({content: content});
infowindow.open(map, marker);
});
}
}
// Initialize the map
google.maps.event.addDomListener(window, 'load', initialize);html, body, #map-canvas {
height: 100%;
margin: 0;
padding: 0;
}
我将在HTML页面上使用它。虽然JSON数据会自动更新，但我无法更改JSON数组。
谢谢！
答案 0 :(得分：3)
我在你的代码中发现了这些问题：
json数组。但是，这不是您的标记数据数组。 json[0]是您的主要对象，json[0].ResponseData是您需要循环的标记数组。所以我把这个值放在一个名为responses的变量中，然后循环使用它。我不知道JSON数据的最外层数组中是否有多个对象;如果是的话，你需要一个外部循环来处理这些。现在我假设只有一个外部对象用json[0]解决。addClicker时，您传入的obj.title并不存在。大概你的意思是obj.BuildingName。infowindow的变量，但在第一次单击该变量不存在时会导致错误。所以我将infowindow声明为全局窗口。那么，我是怎么发现这些问题的呢？使用JavaScript调试器。通常我会在debugger;函数的开头添加一个initialize()语句，然后单步执行代码以查看发生了什么。这将揭示主循环设置var obj = json[i];的位置，它不会获得预期值。
这在普通网页上效果很好，但它在SO上的嵌入式代码段中看起来效果不佳。 （调试器显示错误的源代码行。）因此，我开始添加console.log();语句，看起来可能出现问题，例如在console.log( 'obj:', obj );赋值后立即var obj =。
此外，根据标记的位置自动缩放和居中地图也很不错。我使用为每个标记扩展的LatLngBounds添加了一些代码，然后在创建所有标记后添加map.fitBounds()。如果你这样做，你不需要在第一次创建地图时明确缩放和居中，所以我删除了它们。 （否则地图会显示在一个位置，然后重新定位。）
fitBounds()的一个警告：如果有没有标记，则地图根本不会显示。要处理这种情况，您需要检查responses.length为零的情况，并使用默认值调用map.setZoom()和map.setCenter()。
我使用////标记了更改的行，以便于查找：
var map, infowindow; ////
// The JSON data
var json = [{
"OpperationErrorMsg":"",
"IsSuccess":true,
"ResultId":1000,
"Timestamp":"2016-10-12T18:00:07.0232702Z",
"Echo":null,
"InSandbox":true,
"DebugMessages":[
],
"MissingDetails":[
],
"ResponseData":[
{
"CallTimeLocal":"2016-10-10T06:28:48.7330000",
"IncidentId":3374,
"IncidentNumber":"HC2016004034",
"CallTime":"2016-10-10T10:28:48.7330000",
"ElapsedSeconds":0,
"Location":"2712 E HANNA AVE",
"BuildingName":null,
"BuildingNumber":null,
"NatureId":6743,
"FirePriorityId":1,
"CoordinateX":-82.429500000000,
"CoordinateY":28.003389000000
},
{
"CallTimeLocal":"2016-10-10T11:28:36.7000000",
"IncidentId":3382,
"IncidentNumber":"HC2016004042",
"CallTime":"2016-10-10T15:28:36.7000000",
"ElapsedSeconds":0,
"Location":"1220 APOLLO BEACH BLVD S",
"BuildingName":"Apollo Beach Marina",
"BuildingNumber":null,
"NatureId":8035,
"FirePriorityId":1,
"CoordinateX":-82.422369000000,
"CoordinateY":27.781254000000
},
{
"CallTimeLocal":"2016-10-10T14:29:59.8830000",
"IncidentId":3387,
"IncidentNumber":"HC2016004047",
"CallTime":"2016-10-10T18:29:59.8830000",
"ElapsedSeconds":0,
"Location":"9600 SHELDONWOOD RD",
"BuildingName":null,
"BuildingNumber":null,
"NatureId":6420,
"FirePriorityId":12,
"CoordinateX":-82.580530000000,
"CoordinateY":28.034779000000
},
{
"CallTimeLocal":"2016-10-10T15:27:37.7270000",
"IncidentId":3389,
"IncidentNumber":"HC2016004049",
"CallTime":"2016-10-10T19:27:37.7270000",
"ElapsedSeconds":0,
"Location":"4691 GALLAGHER RD",
"BuildingName":"Strawberry Crest High School",
"BuildingNumber":null,
"NatureId":7873,
"FirePriorityId":2,
"CoordinateX":-82.236450000000,
"CoordinateY":28.021233000000
}
],
"CurrentStatusData":null
}];
function initialize() {
// Giving the map som options
var mapOptions = {
////
};
// Creating the map
map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
var bounds = new google.maps.LatLngBounds(); ////
// Looping through all the entries from the JSON data
var responses = json[0].ResponseData; ////
for(var i = 0; i < responses.length; i++) { ////
// Current object
var obj = responses[i]; ////
// Adding a new marker for the object
var position =
new google.maps.LatLng( obj.CoordinateY, obj.CoordinateX ); ////
bounds.extend( position ); ////
var marker = new google.maps.Marker({
position: position, ////
map: map,
draggable: true,
animation: google.maps.Animation.DROP,
title: obj.BuildingName
});
// Adding a new info window for the object
var clicker = addClicker(marker, obj.BuildingName); ////
} // end loop
map.fitBounds( bounds ); ////
// Adding a new click event listener for the object
function addClicker(marker, content) {
google.maps.event.addListener(marker, 'click', function() {
if (infowindow) {infowindow.close();}
infowindow = new google.maps.InfoWindow({content: content});
infowindow.open(map, marker);
});
}
}
// Initialize the map
google.maps.event.addDomListener(window, 'load', initialize);html, body, #map-canvas {
height: 100%;
margin: 0;
padding: 0;
} <script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=true"></script>
<script src="https:////cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<div id="map-canvas"></div>