Question

我使用Google地方自动填充功能来提示地点。现在这就是我想要的：当用户键入不在谷歌数据库中的位置时，即谷歌返回零结果，我需要能够捕获零结果的事件，并激活我的自定义自动完成。

如何找到google返回零结果的时间？如果结果为零，则autocomplete.getPlace（）将返回状态，但这是在place_changed事件中，仅当用户从下拉列表中选择建议时才会触发该事件。如何在place_changed事件之外使其工作？

这是我使用的代码，请基于此提出建议：

autocomplete = new google.maps.places.Autocomplete(input,options);
google.maps.event.addListener(autocomplete, 'place_changed', function() {
   var place = autocomplete.getPlace();
   document.getElementById('place_name').value = place.name;
   document.getElementById('location_lat').value = place.geometry.location.lat();
   document.getElementById('location_lon').value = place.geometry.location.lng();
   document.getElementById('location_add').value = place.formatted_address;
   $('#locationInput').attr('title', place.formatted_address);
});

Answer 1

找到了一个技巧，

AutoComplete由输入节点的keyup事件触发，然后：

如果没有结果，请按display: none;隐藏结果下拉列表

或

如果有结果

，则按明确display样式显示结果下拉列表

您可以按document.getElementsByClassName('pac-container')[0]（本机）或$('.pac-container')（jQuery）获取下拉列表

因此，只需将下拉列表的display设置为“阻止”，然后跟踪它以检测结果状态。

从google official sample修改的简单示例：

<!DOCTYPE html>
<html>
    <head>
        <title>Google Maps JavaScript API v3 Example: Places Autocomplete</title>
        <script src="https://maps.googleapis.com/maps/api/js?sensor=false&libraries=places"
            type="text/javascript"></script>

        <style type="text/css">
            body {
                font-family: sans-serif;
                font-size: 14px;
            }
            #map_canvas {
                height: 400px;
                width: 600px;
                margin-top: 0.6em;
            }
        </style>

        <script type="text/javascript">
            var ns = {}; // a name space
            ns.checktimes = 0; // a couter of check times
            // the check function
            // @param dropdown: the drop-down list of Places.AutoComplete
            // @param msg: the div to show message
            ns._doCheck = function (dropdown, msg) {
                if (dropdown.style.display == '') {
                    msg.innerHTML = 'has results? true';
                    ns.checkTimer = null;
                }
                else if (dropdown.style.display == 'none') {
                    msg.innerHTML = 'has results? false';
                    ns.checkTimer = null;
                } else if (ns.checktimes < 20) { // check at most 10 seconds
                    ns.checktimes++;
                    ns.checkTimer = setTimeout(function () {
                        ns._doCheck(dropdown, msg);
                    }, 500);
                }
            }
            function initialize() {
                var mapOptions = {
                    center: new google.maps.LatLng(-33.8688, 151.2195),
                    zoom: 13,
                    mapTypeId: google.maps.MapTypeId.ROADMAP
                };
            var map = new google.maps.Map(document.getElementById('map_canvas'),
                mapOptions);

            var input = document.getElementById('searchTextField');
            var autocomplete = new google.maps.places.Autocomplete(input);

            autocomplete.bindTo('bounds', map);

            var infowindow = new google.maps.InfoWindow();
            var marker = new google.maps.Marker({
                map: map
            });

            google.maps.event.addListener(autocomplete, 'place_changed', function() {
                infowindow.close();
                var place = autocomplete.getPlace();
            if (place.geometry.viewport) {
                map.fitBounds(place.geometry.viewport);
            } else {
                map.setCenter(place.geometry.location);
                map.setZoom(17);  // Why 17? Because it looks good.
            }

            var image = new google.maps.MarkerImage(
                place.icon,
                new google.maps.Size(71, 71),
                new google.maps.Point(0, 0),
                new google.maps.Point(17, 34),
                new google.maps.Size(35, 35));
            marker.setIcon(image);
            marker.setPosition(place.geometry.location);

            var address = '';
            if (place.address_components) {
                address = [(place.address_components[0] &&
                place.address_components[0].short_name || ''),
                (place.address_components[1] &&
                place.address_components[1].short_name || ''),
                (place.address_components[2] &&
                place.address_components[2].short_name || '')
                ].join(' ');
            }

            infowindow.setContent('<div><strong>' + place.name + '</strong><br>' + address);
            infowindow.open(map, marker);
            // update stored value
            ns.oldValue = document.getElementById('searchTextField').value;
        });

        // Sets a listener on a radio button to change the filter type on Places
        // Autocomplete.
        function setupClickListener(id, types) {
            var radioButton = document.getElementById(id);
            google.maps.event.addDomListener(radioButton, 'click', function() {
            autocomplete.setTypes(types);
            });
        }

        setupClickListener('changetype-all', []);
        setupClickListener('changetype-establishment', ['establishment']);
        setupClickListener('changetype-geocode', ['geocode']);
        }

        // to check whether responsee and has results
        function startCheck () {
            // the input node
            var inp = document.getElementById('searchTextField'),
                value = inp.value; // value of input node
            if (value && ns.oldValue != value) { // has value and changed, start check
                // drop-down list and message div
                var dropdown = document.getElementsByClassName('pac-container')[0],
                    msg = document.getElementById('msg');
                // trick! change style to display='block'
                dropdown.style.display = 'block';
                // update stored value
                ns.oldValue = value;
                // initiate checktimes
                ns.checktimes = 0;
                // clear previous timer if exists
                if (ns.checkTimer)
                    clearTimeout (ns.checkTimer);
                ns.checkTimer = setTimeout(function () {
                    ns._doCheck(dropdown, msg);
                }, 500);
            }
        }
        google.maps.event.addDomListener(window, 'load', initialize);
    </script>
    </head>
    <body>
        <div>
            <div id="msg">has results? </div>
            <input id="searchTextField" type="text" size="50" onkeyup="startCheck();">
            <input type="radio" name="type" id="changetype-all" checked="checked">
            <label for="changetype-all">All</label>

            <input type="radio" name="type" id="changetype-establishment">
            <label for="changetype-establishment">Establishments</label>

            <input type="radio" name="type" id="changetype-geocode">
            <label for="changetype-geocode">Geocodes</lable>
        </div>
        <div id="map_canvas"></div>
    </body>
</html>

Answer 2

我认为您的方案可能与Google返回零结果不同。您的问题中的一个假设是，place_changed事件“仅在[用户从下拉列表中选择建议时才会被触发”]不正确。来自google.maps.places.Autocomplete的{{1}}类事件文档：

当PlaceResult可用于Place时会触发此事件用户已选择。 如果用户输入了该地方的名称控件没有建议并按下Enter键，a 将触发包含用户输入的place_changed事件 name属性，未定义其他属性。

否则，Google应该返回结果，因为用户已经选择了自动填充下拉选项中的一个结果。如果直接用户输入不是推动您的方案的原因，那么检查零结果不应仅涉及检查place_changed属性的一个，一些或一部分，例如：

：google.maps.places.PlaceResult <{1}}
address_components
google.maps.GeocoderAddressComponent
id
name字符串数组（例如[reference，types]或[political，locality]）

Answer 3

您也可以通过这种方式获得结果。预测是Google地图返回的数组。

const displaySuggestions = (predictions, status) => {
      if (status !== google.maps.places.PlacesServiceStatus.OK) {
        if (status === 'ZERO_RESULTS') {
          alert('zero results found')
        }
        return;
      }
    };
    // you can create autocompleteService as variable outside the function as well
    const autocompleteService = new google.maps.places.AutocompleteService();
    // input is string of what user types 
    autocompleteService.getPlacePredictions({ input: input, types: ['address'] }, displaySuggestions);

Answer 4

您可以通过简单的方式（输入onChange事件）获得零结果：

const _handleChange = (event, value) => {
    setTimeout(() => {
        const dropdownList = document.getElementsByClassName('pac-container')[0];
        if (dropdownList.childElementCount === 0) {
            // Zero results
        } else {
            // Has results
        }
        console.log('child count:', dropdownList.childElementCount);
    }, 100);
};

查找谷歌地方自动完成时返回零结果

4 个答案: