javascript - Asp.Net Core MVC Google Maps api Plot Ployline from SQL
问题描述
我可以毫不费力地在地图上绘制以下点。但现在我想用折线路径加入点,但继续收到错误:“InvalidValueError:不是数组”。我的代码如下,非常感谢任何帮助。
//控制器动作
public async Task<IActionResult> Index()
{
var requests = _context.Complaints.ToList();
var locations = requests.Where(x=>x.ComplaintId>11830).ToList();
string markers = "[";
int i;
for (i = 0; i < locations.Count; i++)
{
markers += "{";
//markers += string.Format("'title': '{0}',", locations[i].ComplaintId);
markers += string.Format("lat: {0},", locations[i].Lat);
markers += string.Format("lng: {0}", locations[i].Lon);
//markers += string.Format("'description': '{0}'", locations[i].ComplaintId);
markers += "},";
}
markers += "]";
ViewBag.markers = markers;
return View(requests.Take(50));
}
//索引视图
<script type="text/javascript">
var markers = @Html.Raw(ViewBag.markers);
window.onload = function () {
var mapOptions = {
center: new google.maps.LatLng(-43.1022, 147.7485 ),
zoom: 10,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var infoWindow = new google.maps.InfoWindow();
var map = new google.maps.Map(document.getElementById("dvMap"), mapOptions);
for (i = 0; i < markers.length; i++) {
var data = markers[i]
const myLatlng = new google.maps.LatLng(data.lat, data.lng);
const marker = new google.maps.Polyline({
path: myLatlng,
map: map
//title: data.title
});
(function (marker, data) {
google.maps.event.addListener(marker, "click", function (e) {
infoWindow.setContent(data.description);
infoWindow.open(map, marker);
});
})(marker, data);
}
}
</script>
<script src="https://maps.googleapis.com/maps/api/js?#myKeyhidden#"></script>
解决方案
要根据您的数据制作折线,请将 lat/lng 值推入一个数组并将其用作折线的路径。
var map = new google.maps.Map(document.getElementById("dvMap"), mapOptions);
const path = [];
for (i = 0; i < markers.length; i++) {
var data = markers[i]
const myLatlng = new google.maps.LatLng(data.lat, data.lng);
path.push(myLatlng);
const polyline = new google.maps.Polyline({
path: path,
map: map
});
}
代码片段:
var markers = [{lat:-43.1022, lng: 147.7485},
{lat:-43.14021, lng: 147.7486},
{lat:-43.1020, lng: 147.7588},
{lat:-43.15019, lng: 147.7690}];// @Html.Raw(ViewBag.markers);
window.onload = function() {
var mapOptions = {
center: new google.maps.LatLng(-43.1022, 147.7485),
zoom: 10,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("dvMap"), mapOptions);
const path = [];
for (i = 0; i < markers.length; i++) {
var data = markers[i]
const myLatlng = new google.maps.LatLng(data.lat, data.lng);
path.push(myLatlng);
const polyline = new google.maps.Polyline({
path: path,
map: map
//title: data.title
});
}
}
html,
body,
#dvMap {
height: 100%;
width: 100%;
margin: 0;
padding: 0;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<html>
<body>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></script>
<div id="dvMap"></div>
</body>
</html>
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