Google Maps V3（带有自定义信息框的 PHP/MYSQL）

Question

我正在使用带有 PHP/MSQL 的谷歌地图，我已经阅读了谷歌上的文档并从那里获取代码。

我想显示像this example 这样的自定义框。我的代码一切正常，除了框中的文本，我一直是实际上是我数据库中最后一个条目的文本......如何管理这个？

var customIcons = {
  0: {
    icon: 'gif_blue.gif',
    shadow: 'gif_blue.gif'
  },
  1: {
    icon: 'gif_green.gif',
    shadow: 'gif_green.gif'
  }
};

function initialize() {
  var map = new google.maps.Map(document.getElementById("map_canvas"), {
    center: new google.maps.LatLng(51.5001524,  -0.1262362),
    zoom: 14,
    mapTypeId: 'terrain'
  });

  // Change this depending on the name of your PHP file
  downloadUrl("xml.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
      });




    var boxText = document.createElement("div");
    boxText.style.cssText = "border: 1px solid black; margin-top: 8px; background: yellow; padding: 5px;";
    boxText.innerHTML = "Nom : <b>" + name + "</b> <br/>Adresse :" + address + "</b> <br/>Type :" + type;

    var myOptions = {
             content: boxText
            ,disableAutoPan: false
            ,maxWidth: 0
            ,pixelOffset: new google.maps.Size(-140, 0)
            ,zIndex: null
            ,boxStyle: { 
              background: "url('tipbox.gif') no-repeat"
              ,opacity: 0.75
              ,width: "280px"
             }
            ,closeBoxMargin: "10px 2px 2px 2px"
            ,closeBoxURL: "http://www.google.com/intl/en_us/mapfiles/close.gif"
            ,infoBoxClearance: new google.maps.Size(1, 1)
            ,isHidden: false
            ,pane: "floatPane"
            ,enableEventPropagation: false
    };

            var ib = new InfoBox(myOptions);
            //THE PROBLEM SHOULD BE HERE :
            google.maps.event.addListener(marker, 'click', (function(marker, i) {
            return function() {
              ib.open(map, marker);
            }
          })(marker, i));

    }

  });

}
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() {}

Answer 1

问题在于JavaScript does not have block scoping。您在此循环中声明的所有变量：

for (var i = 0; i < markers.length; i++) {
    /* declarations here */
}

存在于您定义的匿名回调范围内 (downloadUrl("xml.php", function(data) { /* ... */ })。我看到您已尝试通过您评论的立即函数调用来解决此问题，但您没有正确执行。

---

这应该可行：

function initialize() {
    var map = new google.maps.Map(document.getElementById("map_canvas"), {
        center: new google.maps.LatLng(51.5001524, -0.1262362),
        zoom: 14,
        mapTypeId: 'terrain'
    });

    // Change this depending on the name of your PHP file
    downloadUrl("xml.php", function(data) {
        function createMarker(markerXML) {
            var name = markerXML.getAttribute("name"),
                address = markerXML.getAttribute("address"),
                type = markerXML.getAttribute("type"),
                lat = parseFloat(markerXML.getAttribute("lat")),
                lng = parseFloat(markerXML.getAttribute("lng")),

                icon = customIcons[type] || {},

                marker = new google.maps.Marker({
                    map: map,
                    position: new google.maps.LatLng(lat, lng),
                    icon: icon.icon,
                    shadow: icon.shadow
                }),

                boxText = document.createElement("div");

            boxText.style.cssText = "border: 1px solid black; margin-top: 8px; background: yellow; padding: 5px;";
            boxText.innerHTML = "Nom : <b>" + name + "</b> <br/>Adresse :" + address + "</b> <br/>Type :" + type;

            var myOptions = {
                content: boxText,
                disableAutoPan: false,
                maxWidth: 0,
                pixelOffset: new google.maps.Size(-140, 0),
                zIndex: null,
                boxStyle: {
                    background: "url('tipbox.gif') no-repeat",
                    opacity: 0.75,
                    width: "280px"
                },
                closeBoxMargin: "10px 2px 2px 2px",
                closeBoxURL: "http://www.google.com/intl/en_us/mapfiles/close.gif",
                infoBoxClearance: new google.maps.Size(1, 1),
                isHidden: false,
                pane: "floatPane",
                enableEventPropagation: false
            };

            var infoBox = new InfoBox(myOptions);

            google.maps.event.addListener(marker, 'click', function () {
                    infoBox.open(map, marker);
                }
            });
        }

        var xml = data.responseXML,
            markers = xml.documentElement.getElementsByTagName("marker"),
            numMarkers = markers.length;

        for (var i = 0; i < numMarkers; i++) {
            createMarker(markers[i]);
        }
    });
}

除了一些小的风格和性能调整之外，我改变的唯一是：

1. 将for 循环中的逻辑分解为单独的函数
2. 删除google.maps.event.addListener 中无意义的立即函数调用