Plot polyline in Google Maps

问题

I'm exploring Google Maps Direction API and noticed I get an overview_polyline -> points result. I was able to enter that value in the "Encoded Polyline" field here: https://developers.google.com/maps/documentation/utilities/polylineutility. The result seems to be the actual driving directions from start location to end location. The data looks right to me.

I'd like to see this in a Google Map, but without all the map markers in between the start and end locations. How do I take this information and plot it on Google Maps?

回答1:

From the Google Maps Javascript API Developers Guide: Geometry Library: Geometry Encoding

To decode an encoded path, simply call decodePath() passing the method the encoded string.

The caveat, is beware of backslash encoding (replace any occurrences in your encoded path string of "\\" with "\" if you have problems)

example fiddle

code snippet:

var map;
var bounds = new google.maps.LatLngBounds();

function initialize() {
  map = new google.maps.Map(
    document.getElementById("map_canvas"), {
      center: new google.maps.LatLng(34, 108),
      zoom: 13,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    });

  var jsonData = {
    "overview_polyline": {
      "points": "e`miGhmocNaN~DiBiNe@gEkEek@kNez@cJqq@sk@pGos@v]_}@aF_y@qm@qDe~@w]g~@gZ_Jo_@m_@yNsFgUpMov@~QebBrJq`BjTsx@w@kOqbEq_@qkCcf@}}Dej@yzCuf@o{Ba]m~EtVewAnBa`@sNmm@}dDufGqwA_|D_z@g~CmtBkuOrBmtCyG_yCam@{`Ee]qkB}d@ucDmDe|Aha@e}At]{v@xD}e@yf@aeIm^{rEgp@ahBiZu`BkVueH}gDwuXu`Fi__@yZecHgoAgyIl[ybCo^sgD_n@akBaJmeBog@yyAe`@ayB~FifCjNkmAzTwpAgf@cpFy~@{lJsg@ojHyi@e_Fq}@o`Dog@}tBoYmz@y`@sf@qf@ohCkLugBuv@seAg[ul@mMowBqc@iiC}eAcwCqm@_fBmuAypFyIiqA}BwyBy`@ogAwt@ypBezC{dIahBwxJgb@ytCw~AwvJkQwu@{t@yrCg{@s{Fgb@ehDzKsdAxO}vAiRmpCwcAorNuwAgdS_r@imJq[orAk]wrA_TyzAnFefAa\\guB_OmwAwF{tCwMcbDcr@m}_@}Qo_RgMo|A|d@kpAne@u{Brb@wnDzNkuB_D{v@eSgf@w\\ieAyb@guCii@ifCga@i_Amc@m]urAyoD}o@kiIsr@opQuLkhAc_@q`Bq\\}bEeEyi@iE}t@pHi|@tBmlBebB{qHq_BinFoWgpBoDuqEob@k{ConAedC}L}h@yd@yfAgz@}gAaZi_@m}@mcBwyAaj@_bBg|@csBm_Bo|BkaC{iBqsB_YqyBxEmtBks@aoB{RgLa~@bCcr@cLyoAemBeg@gt@_}@e`@on@uu@etA}vCqp@ubAklDgeGmxFiqHaqFoeHa[wbBu]}gAuoDeeG{uAooB_uAsy@om@ugAu_L{xSshEe_KieDm|KcfIcuWeUcOwy@aP{QuUg`BipF{P_l@klAgaEmjEs}NsvAiyFs}@izFjwAqrGtHkbCeB{cEql@g~CgSk|@mB}oAqNekEgw@cmDo_BgjFqqC}gH}`CwvG}cA{cB}nFowQ_t@an@efBmpE_oAsvCka@mwBk_CqbGuu@qfB{uAmrDivDw|E{nAqbDmpCyaJgdCejHk~@owAsw@adAm_@abA}Ven@qCou@cKeiBca@_cBmlAyjAsn@_kCk}@smDkVg{Bk}@gcHox@_sEaPwdC~KazF{EcpCrEmeGl]auBeEi~@yiAovCwwAgsC{i@oSsbAu~Ay_AmaBk_@iKak@mh@_BmBk@wHvG@dBvA"
    }
  };
  var path = google.maps.geometry.encoding.decodePath(jsonData.overview_polyline.points);
  console.log(path);
  for (var i = 0; i < path.length; i++) {
    bounds.extend(path[i]);
  }

  var polyline = new google.maps.Polyline({
    path: path,
    strokeColor: '#FF0000',
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: '#FF0000',
    fillOpacity: 0.35,
    map: map
      // strokeColor: "#0000FF",
      // strokeOpacity: 1.0,
      // strokeWeight: 2
  });
  polyline.setMap(map);
  map.fitBounds(bounds);

}


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

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

<script src="https://maps.googleapis.com/maps/api/js?libraries=geometry"></script>
<div id="map_canvas" style="border: 2px solid #3872ac;"></div>

来源：https://stackoverflow.com/questions/29481300/plot-polyline-in-google-maps

标签

google-maps

google-direction