Question

我正在尝试创建一个使用不同Fusion Tables的网站。有一个下拉菜单，有几个州。每个州都有自己的Fusion Table

我想这样做，当你选择一个状态时，地图会加载该状态的'Fusion Table。

我该怎么做？

到目前为止，我的JavaScript代码如下（filename是'script.js'）。下面是HTML代码。

当我通过下拉列表更改状态时，我希望地图在下拉列表中加载状态的Fusion Table地图。现在，它没有这样做。

$(document).ready(function(){
    var states = {
        'Alabama':'3348442',
        'Alaska':'3370522'
    };
    // SECTION 1: ADDING HTML TO DOM
    var bodyDivs = [
        '<div id="map-canvas" />',
        '<div id="address-form-container" />',
        '<div id="state-select-container"><select id="state-select" /></div>'
    ];

    var addressContainer = [
        '<span id="form pretext"> Enter a city name or address </span>',
        '<input id="address" type="textbox" />',
        '<input type="button" value="Search" />'
    ];

    // Append the body to <html>
    $('html').append('<body />');
    for (var i=0; i<bodyDivs.length; i++){
        $('body').append(bodyDivs[i]);
    };

    // Append the address form to <body>
    for (var i=0; i<addressContainer.length; i++){
        $('div#address-form-container').append(addressContainer[i]);
    };

    // Append state names to the body
    for (var state in states){
        $('select').append('<option value='+state+'>'+state+'</option>');
    };
    // DONE ADDING HTML TO DOM


    // SECTION 2: Create the Google map with the coordinates and add the Fusion Tables layer to it. Plus, it zooms and centers to whatever state is selected.
    var geocoder;
    var gmap;
    var locationColumn = "'geometry'";
    var condition = "'Median income (dollars)'>0";
    var selectedState = document.getElementById("state-select").value;
    var tableId = states[selectedState];    
    var mapOptions = {
        mapTypeId: google.maps.MapTypeId.ROADMAP
    };

    function initialize(){
        geocoder = new google.maps.Geocoder(); // This variables is used to automate zooming and centering in this script
        gmap = new google.maps.Map(document.getElementById("map-canvas"), mapOptions); // Removing this removes the Google Maps layer, but would keep any layers on top of it

        // The Fusion Tables layer variable
        var layer = new google.maps.FusionTablesLayer({
            query: {
                select: locationColumn,
                from: tableId,
                where: condition
            }
        });

        // This code snippet centers and zooms the map to the selected state.
        geocoder.geocode(
            {
                'address':selectedState
            },
            function(results,status){
                var sw = results[0].geometry.viewport.getSouthWest();
                var ne = results[0].geometry.viewport.getNorthEast();
                var bounds = new google.maps.LatLngBounds(sw,ne);

                gmap.fitBounds(bounds)
            }
        );

        layer.setMap(gmap);

        google.maps.event.addDomListener(selectedState,'change',function(){
            updateMap(layer,tableId,locationColumn);
        });         
    }


    // SECTION 3: Find the address once the button is clicked
    $(':button').click(
        function codeAddress(){
            var address = document.getElementById("address").value;

            geocoder.geocode(
                {
                    'address':address
                },
                function(results,status){
                    if(status===google.maps.GeocoderStatus.OK){
                        var addressSW = results[0].geometry.viewport.getSouthWest();
                        var addressNE = results[0].geometry.viewport.getNorthEast();
                        var bounds = new google.maps.LatLngBounds(addressSW,addressNE);

                        gmap.fitBounds(bounds);
                    } else {
                        alert("Couldn't find address for the following reason: " + status + ". Sorry about that. Please try another address.");
                    }
                }
            );
        }
    );


    function updateMap(layer,tableId,locationColumn){
        if (selectedState) {
            tableId = states[selectedState];

            layer.setOptions({
                query: {
                    select: locationColumn,
                    from: tableId,
                    where: condition
                }
            });

            geocoder.geocode(
                {
                    'address':selectedState
                },
                function(results,status){
                    var sw = results[0].geometry.viewport.getSouthWest();
                    var ne = results[0].geometry.viewport.getNorthEast();
                    var bounds = new google.maps.LatLngBounds(sw,ne);

                    gmap.fitBounds(bounds)
                }
            );          
        }
    }

    google.maps.event.addDomListener(window, 'load', initialize);
});

CSS：

#map-canvas {
height: 800px;
width: 1000px;

}

HTML code：

<html>
    <head>
        <meta charset="utf8">
        <title>TESTING THE MAPS</title>
        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
        <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
        <script type="text/javascript" src="public/js/script.js"></script>
    </head>
</html>

编辑：指向HTML，CSS和JS文件的链接---
http://speedy.sh/xRkZF/maptest.html
http://speedy.sh/zSt5p/script.js
http://speedy.sh/uCPxZ/style.css

Answer 1

您已经对selectedState进行了硬编码，但您需要在下拉列表更改时获取当前值。

将更改侦听器修改为：

google.maps.event.addDomListener(document.getElementById('state-select'),
  'change',
  function(){
        updateMap(layer,this.value,locationColumn);
    });

现在传递给updateMap的第二个参数将是下拉列表中的选定状态。同时修改updateMap，将第二个参数的名称更改为selectedState：



function updateMap(layer,selectedState,locationColumn){
  //function code may stay as it is
  }

现在一切都应该正常工作。

在Fusion Tables和Google Maps API中，如何根据下拉菜单选择更改Tables图层和Map位置？

1 个答案: