Question

我正在尝试将标记添加到谷歌地图中，并从mysql数据库中查询坐标。脚本如下所示，位于名为connection.php的文件中。

$query = "SELECT site, latitude, longitude, pollution FROM pollution_monitoring.locations";
$result = mysqli_query($conn, $query);

while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) 
{
    $site      = $row['site'];
    $latitude  = $row['latitude'];
    $longitude = $row['longitude'];
    $pollution = $row['pollution'];

    echo ("addMarker($latitude,$longitude,'<b>$site</b><br/>$pollution');\n");     
}

addMarker（）是一个已在下面的文件中定义的JavaScript函数

var icon = new google.maps.MarkerImage("http://maps.google.com/mapfiles/ms/micons/red.png",
    new google.maps.Size(32, 32), new google.maps.Point(0, 0),
    new google.maps.Point(16, 32));
var center = null;
var map = null;
var currentPopup;
var bounds = new google.maps.LatLngBounds();
google.maps.event.addDomListener(window, 'load', initialize);

function addMarker(lat, lng, info) {
    var pt = new google.maps.LatLng(lat, lng);
    bounds.extend(pt);
    var marker = new google.maps.Marker({
        position: pt,
        icon: icon,
        map: map
    });
    var popup = new google.maps.InfoWindow({
        content: info,
        maxWidth: 500
    });
    google.maps.event.addListener(marker, "click", function() {
        if (currentPopup != null) {
            currentPopup.close();
            currentPopup = null;
        }
        popup.open(map, marker);
        currentPopup = popup;
    });
    google.maps.event.addListener(popup, "closeclick", function() {
        map.panTo(center);
        currentPopup = null;
    });
}

function initialize() {
    var mapProp = {
        center: new google.maps.LatLng(-29.335989, 27.483622999999966),
        zoom: 17,
        mapTypeId: google.maps.MapTypeId.HYBRID,
        mapTypeControl: true,
        zoomControl: true,
        scaleControl: true,
        streetViewControl: true,
        overviewMapControl: true,
        rotateControl: true,
        mapTypeControlOptions: {
            style: google.maps.MapTypeControlStyle.HORIZONTAL_BAR
        },
        navigationControl: true,
        navigationControlOptions: {
            style: google.maps.NavigationControlStyle.SMALL
        }
    };
    $.get('connection.php');

    var map = new google.maps.Map(document.getElementById("googleMap"), mapProp);
    google.maps.event.addDomListener(window, 'load', initialize);

以上脚本用于加载Google地图，并且必须将标记添加到地图中。我原以为php脚本（addMarker函数）的结果会被运行并将标记添加到地图中，但这不会发生。然后将JavaScript包含在jsp文件中。地图会加载，但不会添加任何标记。

我做错了什么？

Answer 1

您应该重写您的php脚本以生成JSON数据：

header('Content-Type: application/json');

$query = "SELECT site,latitude,longitude,pollution FROM pollution_monitoring.locations";
$result = mysqli_query($conn,$query);

$i = 0;
echo '[';
while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) 
{
    if ($i++ != 0) echo ',';
    echo json_encode($row);    
}
echo ']';

然后使用JavaScript添加标记：

$.getJSON('connection.php', function(data) {
    for (var i = 0; i < data[i]; i++) {
        addMarker(data[i].latitude, data[i].longitude, "<b>" + data[i].site + "</b><br />" + data[i].pollution);
    }
});

从javascript

1 个答案: