我有以下XML文件 -
<marker>
<marker id="1" name="Graeme Hall Roundabout" address="Graeme Hall Roundabout" lat="13.077160" lng="-59.568535" type="suv"/>
<marker id="2" name="Deighton Griffith Junction" address="Deighton Griffith Junction" lat="13.080240" lng="-59.550358" type="suv"/>
<marker id="3" name="Airport Roundabout" address="Airport Roundabout" lat="13.080238" lng="-59.491413" type="zr"/>
<marker id="4" name="Waterford Bottom" address="Waterford Bottom" lat="13.120412" lng="-59.599075" type="zr"/>
</marker>并且正在使用本教程以下脚本来阅读它 -
<!DOCTYPE html >
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
<title>Using MySQL and PHP with Google Maps</title>
<style>
/* Always set the map height explicitly to define the size of the div
* element that contains the map. */
#map {
height: 100%;
}
/* Optional: Makes the sample page fill the window. */
html, body {
height: 100%;
margin: 0;
padding: 0;
}
</style>
</head>
<body>
<div id="map"></div>
<script>
var customLabel = {
restaurant: {
label: 'R'
},
bar: {
label: 'B'
}
};
function initMap() {
var map = new google.maps.Map(document.getElementById('map'), {
center: new google.maps.LatLng(13.179190,-59.561025),
zoom: 12
});
var infoWindow = new google.maps.InfoWindow;
// Change this depending on the name of your PHP or XML file
downloadUrl('xml.php', function(data) {
var xml = data.responseXML;
***var markers = xml.documentElement.getElementsByTagName('marker');***
Array.prototype.forEach.call(markers, function(markerElem) {
var id = markerElem.getAttribute('id');
var name = markerElem.getAttribute('name');
var address = markerElem.getAttribute('address');
var type = markerElem.getAttribute('type');
var point = new google.maps.LatLng(
parseFloat(markerElem.getAttribute('lat')),
parseFloat(markerElem.getAttribute('lng')));
var infowincontent = document.createElement('div');
var strong = document.createElement('strong');
strong.textContent = name
infowincontent.appendChild(strong);
infowincontent.appendChild(document.createElement('br'));
var text = document.createElement('text');
text.textContent = address
infowincontent.appendChild(text);
var icon = customLabel[type] || {};
var marker = new google.maps.Marker({
map: map,
position: point,
label: icon.label
});
marker.addListener('click', function() {
infoWindow.setContent(infowincontent);
infoWindow.open(map, marker);
});
});
});
}
function downloadUrl(url, callback) {
var request = window.ActiveXObject ?
new ActiveXObject('Microsoft.XMLHTTP') :
new XMLHttpRequest;
request.onreadystatechange = function() {
if (request.readyState == 4) {
request.onreadystatechange = doNothing;
callback(request, request.status);
}
};
request.open('GET', url, true);
request.send(null);
}
function doNothing() {}
</script>
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBoE2qN1puD-faj_5lIC_O464doKaoJDs0&callback=initMap">
</script>
</body>
</html>但是，我在执行时收到以下错误。
xml.html:45 Uncaught TypeError: Cannot read property 'documentElement' of null
at xml.html:45
at XMLHttpRequest.request.onreadystatechange (xml.html:88)我已经验证了XML文件并且它很好，所以我不明白为什么错误继续发生。
任何协助将不胜感激。
谢谢
史蒂夫
更改
新的XMLHttpRequest;
自
new XMLHttpRequest((;
在downloadUrl()功能中。
在 Javascript 中，您可以使用您可能知道的functionName()调用函数或调用函数构造函数 - 我相信这只是您的拼写错误。
还要确保您的服务器返回 xml 响应。