我正在关注如何在 php/mysql 中使用谷歌地图的教程：https ://developers.google.com/maps/articles/phpsqlajax_v3
在 Firefox 中一切正常，但在 Chrome 或资源管理器中没有显示标记。在 chrome 控制台中，我收到以下错误：
未捕获的类型错误：无法读取 null /maps/:35（匿名函数）/maps/:35 request.onreadystatechange 的属性“documentElement”
这是我的代码（与教程中的完全相同）：
<!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>PHP/MySQL & Google Maps Example</title>
<script type="text/javascript"
src="http://maps.googleapis.com/maps/api/js?
key=AIzaSyAGdu4GFzdG3B203KSHApI5hA9HQmGKRrc&sensor=true">
</script>
<script type="text/javascript">
//<![CDATA[
var customIcons = {
restaurant: {
icon: 'http://labs.google.com/ridefinder/images/mm_20_blue.png',
shadow: 'http://labs.google.com/ridefinder/images/mm_20_shadow.png'
},
bar: {
icon: 'http://labs.google.com/ridefinder/images/mm_20_red.png',
shadow: 'http://labs.google.com/ridefinder/images/mm_20_shadow.png'
}
};
function load() {
var map = new google.maps.Map(document.getElementById("map"), {
center: new google.maps.LatLng(47.6145, -122.3418),
zoom: 13,
mapTypeId: 'roadmap'
});
var infoWindow = new google.maps.InfoWindow;
// Change this depending on the name of your PHP file
downloadUrl("genxml.php", function(data) {
var xml = data.responseXML;
var markers = xml.documentElement.getElementsByTagName("marker");
for (var i = 0; i < markers.length; i++) {
var name = markers[i].getAttribute("name");
var address = markers[i].getAttribute("address");
var type = markers[i].getAttribute("type");
var point = new google.maps.LatLng(
parseFloat(markers[i].getAttribute("lat")),
parseFloat(markers[i].getAttribute("lng")));
var html = "<b>" + name + "</b> <br/>" + address;
var icon = customIcons[type] || {};
var marker = new google.maps.Marker({
map: map,
position: point,
icon: icon.icon,
shadow: icon.shadow
});
bindInfoWindow(marker, map, infoWindow, html);
}
});
}
function bindInfoWindow(marker, map, infoWindow, html) {
google.maps.event.addListener(marker, 'click', function() {
infoWindow.setContent(html);
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>
<body onload="load()">
<div id="map" style="width: 500px; height: 300px"></div>
</body>
</html>
这是输出xml的文件：
<?php
require("db.php");
// Start XML file, create parent node
$dom = new DOMDocument("1.0");
$node = $dom->createElement("markers");
$parnode = $dom->appendChild($node);
// Opens a connection to a MySQL server
$connection=mysql_connect ('maps', $username, $password);
if (!$connection) { die('Not connected : ' . mysql_error());}
// Set the active MySQL database
$db_selected = mysql_select_db($database, $connection);
if (!$db_selected) {
die ('Can\'t use db : ' . mysql_error());
}
// Select all the rows in the markers table
$query = "SELECT * FROM markers WHERE 1";
$result = mysql_query($query);
if (!$result) {
die('Invalid query: ' . mysql_error());
}
header("Content-type: text");
// Iterate through the rows, adding XML nodes for each
while (( $row = mysql_fetch_assoc($result))!==false){
// ADD TO XML DOCUMENT NODE
$marker = $dom->createElement("marker");
$node->appendChild($marker);
$marker->setAttribute("name",$row['name']);
$marker->setAttribute("address", $row['address']);
$marker->setAttribute("lat", $row['lat']);
$marker->setAttribute("lng", $row['lng']);
$marker->setAttribute("type", $row['type']);
}
echo $dom->saveXML();
?>
非常感谢任何帮助！