我正在使用KnockOut JS和google maps api。创建了单页Web应用程序，用户可以通过该应用程序过滤地点的名称，并在地图上更新标记。 HTML代码。
<head>
<title>Google maps</title>
<link rel=stylesheet type=text/css href='css/style.css'>
</head>
<body>
<div class="container">
<div class="options-box">
<h1>Liverpool Pubs and Bars - Anfield</h1>
<hr>
<div>
<input data-bind='value: userInput' id="filter-area" type="text" placeholder="Enter your favorite Pub">
<input data-bind='click: searchedPlace' id="filter-button" type='button' value="Filter">
</div>
<hr>
<div>
<ul data-bind='foreach: allPlaces'>
<div class="pubs" data-bind='text: name, click: $parent.setCurrentPlace'></div>
</ul>
</div>
</div>
<div id='map'></div>
</div>
<script src="https://maps.googleapis.com/maps/api/js?libraries=places,geometry,drawing&key=AIzaSyAJZiVbDVmFXz8_kPBjfugqCj68BPAKE88&callback=initMap"
async defer></script>
<script type="text/javascript" src="js/knockout-3.2.0.js"></script>
<script type="text/javascript" src="js/app.js"></script>
</body>
JS代码：
var ViewModel = function (googleMap, myPlaces, infoWindow, bounds) {
var self = this;
this.map = googleMap;
this.allPlaces = ko.observableArray([]);
this.markers = [];
var geocoder = new google.maps.Geocoder();
myPlaces.forEach(function(place) {
var newObj = new Place(place);
var title = newObj.name;
// Getting the geocode for the place.
geocoder.geocode({ 'address': place.address }, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
marker = new google.maps.Marker({
map: self.map,
position: results[0].geometry.location,
animation: google.maps.Animation.DROP,
title: title,
address: newObj.address
});
self.markers.push(marker);
(function (marker, title) {
google.maps.event.addListener(marker, 'click', function () {
populateinfoWindow(marker, infoWindow);
});
})(marker, title);
bounds.extend(marker.position);
}
});
self.allPlaces.push(newObj);
});
// function to set the current place.
this.clearAllMarkers = function() {
console.log(self.markers.length);
console.log('reaching here');
for( var i = 0; i < self.markers.length; i++) {
//debugger;
// console.log(self.markers[i]);
// Making all markers disappear
self.markers[i].setVisible(false);
//debugger;
}
//debugger;
}
this.setCurrentPlace = function(place) {
//debugger;
self.clearAllMarkers();
for( var i = 0; i < self.markers.length; i++) {
if (place.name == self.markers[i].title) {
self.markers[i].setVisible(true);
(function (marker, title) {
google.maps.event.addListener(marker, 'click', function () {
populateinfoWindow(marker, infoWindow);
});
})(marker, place.name);
bounds.extend(self.markers[i].position);
}
}
}
// filtering places
self.userInput = ko.observable('');
this.searchedPlace = function() {
// clearing all markers.
self.clearAllMarkers();
var p = [];
self.allPlaces = ko.observableArray([]);
for (var i = 0; i < self.markers.length; i++) {
// check if its a substring.
if (self.markers[i].title.toLowerCase().indexOf(self.userInput().toLowerCase()) !== -1) {
// Showing markers.
self.allPlaces.push(new Place({name: self.markers[i].title, address: self.markers[i].address}));
self.markers[i].setVisible(true);
}
}
}
}
var Place = function(data) {
this.name = data.name;
this.address = data.address;
}
var createMap = function () {
var map;
// Constructor creates a new map - only center and zoom are required.
// Centering map at Anfield.
map = new google.maps.Map(document.getElementById('map'), {
center: {lat: 53.4308294, lng: -2.96083},
mapTypeControl: false,
zoom: 15
});
return map;
}
function initMap() {
google.maps.event.addDomListener(window, 'load', function(){
// list of my places.
var myPlaces = [
{
name: 'The Albert',
address: '185 Walton Breck Rd, Liverpool L4 0RE, UK'
},
{
name: 'Arkles',
address: '77 Anfield Rd, Liverpool L4 0TJ, UK'
},
{
name: 'The Sandon',
address: '178-182 Oakfield Rd, Liverpool L4 0UH, UK'
},
{
name: 'The Park Pub',
address: '216-218 Walton Breck Rd, Liverpool L4 0RQ, UK'
},
{
name: 'The Twelfth Man',
address: '121 Walton Breck Rd, Liverpool L4 0RD, UK'
}
];
var googleMap = createMap();
var infoWindow = new google.maps.InfoWindow();
var bounds = new google.maps.LatLngBounds();
ko.applyBindings(new ViewModel(googleMap, myPlaces, infoWindow, bounds))
});
}
function populateinfoWindow(marker, infoWindow) {
console.log(marker.position.lat());
// Check to make sure the infoWindow is not already opened on this marker.
if (infoWindow.marker != marker) {
infoWindow.marker = marker;
infoWindow.setContent('<div id="text">' + marker.title + '</div>' + '<div id="text">' + marker.address + '</div>');
infoWindow.open(map, marker);
// Make sure the marker property is cleared if the infoWindow is closed.
infoWindow.addListener('closeclick',function(){
infoWindow.setMarker = null;
});
// Get the street View for the place.
var streetView = new google.maps.StreetViewService();
var radius = 50;
function getStreetView(data, status) {
// Check if the status of the google service is OK.
// In case it's ok, then proceed with the panorama view.
if( status == google.maps.StreetViewStatus.OK ) {
var nearStreetViewLocation = data.location.latLng;
var heading = google.maps.geometry.spherical.computeHeading(
nearStreetViewLocation, marker.position);
infoWindow.setContent('<div>' + marker.title + '</div><div id="pano"></div');
var panoramaOptions = {
position: nearStreetViewLocation,
pov: {
heading: heading,
pitch: 30
}
};
var panorama = new google.maps.StreetViewPanorama(
document.getElementById('pano'), panoramaOptions);
} else {
infoWindow.setContent('<div>' + marker.title + '</div>' + '<div>No Street View Found</div>');
}
}
// Calling the above function with the marker data.
streetView.getPanoramaByLocation(marker.position, radius, getStreetView);
infoWindow.open(map, marker);
}
}
标记会相应更新。但是，绑定到self.allPlaces的元素下的列表不会更新。 self.allPlaces（）在函数this.searchedPlace（）中被清除，然后重新创建。但这些变化并没有反映在网页上。
答案 0 :(得分：1)
self.allPlaces = ko.observableArray（[]）;
this.searchedPlace中的此调用会重新创建一个新的observableArray，因此旧的所有订阅者都被省略了。
您应该使用清除数组 self.allPlaces（[]）相反，它为它分配一个空数组，然后继续处理相同的obsevable