如何删除谷歌地图的多个圆圈

Question

我正在尝试通过单击按钮从谷歌地图中删除所有 4 个圆圈，但目前我只能删除一个圆圈。谁能告诉我如何通过单击按钮一次删除多个圆圈。对不起，我是新手。提前谢谢。

我的代码：

<input onclick="removecircle();" type=button value="Remove line">
<input onclick="addcircle();" type=button value="Restore line">
<div id="map"></div>
<script>
var cityCircle;
var citymap = {
chicago: {
center: {lat: 41.878, lng: -87.629},
population: 2714856
},
newyork: {
center: {lat: 40.714, lng: -74.005},
population: 8405837
},
losangeles: {
center: {lat: 34.052, lng: -118.243},
population: 3857799
},
vancouver: {
center: {lat: 49.25, lng: -123.1},
population: 603502
}
};
function initMap() {
// Create the map.
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 4,
center: {lat: 37.090, lng: -95.712},
mapTypeId: 'terrain'
});
// Construct the circle for each value in citymap.
// Note: We scale the area of the circle based on the population.
for (var city in citymap) {
// Add the circle for this city to the map.
cityCircle = new google.maps.Circle({
strokeColor: '#FF0000',
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: '#FF0000',
fillOpacity: 0.35,
map: map,
center: citymap[city].center,
radius: Math.sqrt(citymap[city].population) * 100
});
}
}
function addcircle(){
cityCircle.setMap(map);
}
function removecircle(){
cityCircle.setMap(null);
}

图片 1

图片 2

Answer 1

您需要在全局范围内保留对圆圈(和地图(的引用(可以从 HTML 单击侦听器函数访问它们(。 然后处理所有圆圈以在地图中添加或删除它们。

var circles = [];
var map;
function initMap() {
// Create the map.
map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: {
lat: 37.090,
lng: -95.712
},
mapTypeId: 'terrain'
});
// Construct the circle for each value in citymap.
// Note: We scale the area of the circle based on the population.
for (var city in citymap) {
// Add the circle for this city to the map.
var cityCircle = new google.maps.Circle({
strokeColor: '#FF0000',
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: '#FF0000',
fillOpacity: 0.35,
map: map,
center: citymap[city].center,
radius: Math.sqrt(citymap[city].population) * 100
});
// keep reference to the circle
circles.push(cityCircle);
}
}
function addcircle() {
for (var i = 0; i < circles.length; i++) {
circles[i].setMap(map);
}
}
function removecircle() {
for (var i = 0; i < circles.length; i++) {
circles[i].setMap(null);
}
}

概念验证小提琴

代码片段：

html,
body,
#map {
height: 100%;
margin: 0;
padding: 0;
width: 100%;
}

<input onclick="removecircle();" type=button value="Remove circles">
<input onclick="addcircle();" type=button value="Restore circles">
<script src="https://maps.googleapis.com/maps/api/js" type="text/javascript"></script>
<div id="map"></div>
<script>
var circles = [];
var map;
function initMap() {
// Create the map.
map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: {
lat: 37.090,
lng: -95.712
},
mapTypeId: 'terrain'
});
// Construct the circle for each value in citymap.
// Note: We scale the area of the circle based on the population.
for (var city in citymap) {
// Add the circle for this city to the map.
var cityCircle = new google.maps.Circle({
strokeColor: '#FF0000',
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: '#FF0000',
fillOpacity: 0.35,
map: map,
center: citymap[city].center,
radius: Math.sqrt(citymap[city].population) * 100
});
circles.push(cityCircle);
}
}
function addcircle() {
for (var i = 0; i < circles.length; i++) {
circles[i].setMap(map);
}
}
function removecircle() {
for (var i = 0; i < circles.length; i++) {
circles[i].setMap(null);
}
}
google.maps.event.addDomListener(window, 'load', initMap);
var cityCircle;
var citymap = {
chicago: {
center: {
lat: 41.878,
lng: -87.629
},
population: 2714856
},
newyork: {
center: {
lat: 40.714,
lng: -74.005
},
population: 8405837
},
losangeles: {
center: {
lat: 34.052,
lng: -118.243
},
population: 3857799
},
vancouver: {
center: {
lat: 49.25,
lng: -123.1
},
population: 603502
}
};
</script>