从Google API placesSearch获取总标记数 [英] Get total marker count from Google API placesSearch

问题描述

在示例小提琴中，如何获取地图上显示的标记总数？

  markers.push（marker）
 
我将每个标记推入数组中， code> 

试图获得像这样的标记总数：



  $（'。marker-count span'）。html（markers.length）; 
  

不幸的是，markers.length返回0时，它应该至少返回3.
我在这里有示例代码： http://jsfiddle.net/287C7/

如何显示标记的总数？是否有可能将每个标记添加到我的数组？

我需要知道显示的标记数量，以便我可以在用户没有时提醒用户。 p>

谢谢，

如果您不想查看jsfiddle.net上的代码，请在这里：

  var map，places，tmpLatLng，markers = []; 
 
 var pos = new google.maps.LatLng（51.5033630，-0.1276250）; 
 var mapOptions = {
 zoom：8，
 center：new google.maps.LatLng（51.5033630，-0.1276250）
}; 
 map = new google.maps.Map（document.getElementById（'map-canvas'），
 mapOptions）; 
 //创建地图并引用div＃map-canvas容器
 var markerBounds = new google.maps.LatLngBounds（）; 
 var service = new google.maps.places.PlacesService（map）; 
 
 
 //获取现有地点（ajax）
 //并将它们放在地图上
 
 var request = {
 location ：pos，
 radius：48000，//最大半径
名称：mc donalds
}; 
 function callback（results，status）{
 if（status == google.maps.places.PlacesServiceStatus.OK）{
 for（var i = 0; i< results.length; i ++）{
 createMarker（results [i]）; 
} 
 $（'＃map-canvas'）。attr（data-markers，results.length）; 
 $（'。marker-count span'）。html（markers.length）; 
} else {
 console.log（Places requests failed：+ status）; 
} 
} //结束回调
函数createMarker（place）{
 var prequest = {
 reference：place.reference 
}; 
 var tmpLatLng = place.geometry.location; 
 var marker = new google.maps.Marker（{
 map：map，
 position：place.geometry.location 
}）; 
 markers.push（marker）; 
 markerBounds.extend（tmpLatLng）; 
} //结束createMarker 
 service.nearbySearch（request，callback）; 
  

解决方案

当您运行代码时，placesSearch调用是异步的：

  $（'。marker-count span'）。html（markers.length）; 
  

结果尚未从服务器返回。在更新标记数组后，您需要在回调中执行该操作。

 函数回调（结果，状态）{
 if（status == google.maps.places.PlacesServiceStatus.OK）{
 for（var i = 0; i< results.length; i ++）{
 createMarker（results [i]） ; 
} 
 $（'＃map-canvas'）。attr（data-markers，results.length）; 
 $（'。marker-count span'）。html（markers.length）; 
} else {
 console.log（Places requests failed：+ status）; 
} 
} //结束回调
  

工作小提琴

In the example fiddle, how can I get the total number of markers displayed on the map? I'm pushing each of the markers into an array like this:

markers.push(marker)

And attempting to get the total number of markers like this:

$('.marker-count span').html(markers.length);

Unfortunately, "markers.length" is returning 0 when it should be returning at least 3. I have example code here: http://jsfiddle.net/287C7/

How can I display the total number of markers? Is it not possible to add each marker to my array?

I need to know the amount of markers shown so that I can alert the user if there are none.

Thanks,

In case you don't want to view the code on jsfiddle.net, here it is:

    var map, places, tmpLatLng, markers = [];

var pos = new google.maps.LatLng(51.5033630,-0.1276250);
  var mapOptions = {
    zoom: 8,
    center: new google.maps.LatLng(51.5033630,-0.1276250)
  };
  map = new google.maps.Map(document.getElementById('map-canvas'),
  mapOptions);
    // create the map and reference the div#map-canvas container
    var markerBounds = new google.maps.LatLngBounds();
    var service = new google.maps.places.PlacesService(map);


      // fetch the existing places (ajax) 
      // and put them on the map

        var request = {
          location: pos,
          radius: 48000,  // Max radius
          name: "mc donalds"
        };
        function callback(results, status) {
          if (status == google.maps.places.PlacesServiceStatus.OK) {
            for (var i = 0; i < results.length; i++) {
              createMarker(results[i]);
            }
            $('#map-canvas').attr("data-markers",results.length);
            $('.marker-count span').html(markers.length);                  
          } else {
            console.log("Places request failed: "+status);
          }
        } // end callback
        function createMarker(place) {
          var prequest = {
            reference: place.reference
          };
          var tmpLatLng = place.geometry.location;
          var marker = new google.maps.Marker({
            map: map,
            position: place.geometry.location
          });
          markers.push(marker);
          markerBounds.extend( tmpLatLng );
        } // end createMarker
        service.nearbySearch(request, callback);

解决方案

the placesSearch call is asynchronous, when you run your code:

$('.marker-count span').html(markers.length);

the result hasn't come back from the server yet. You need to do that in the call back after you update the markers array.

        function callback(results, status) {
          if (status == google.maps.places.PlacesServiceStatus.OK) {
            for (var i = 0; i < results.length; i++) {
              createMarker(results[i]);
            }
            $('#map-canvas').attr("data-markers",results.length);
            $('.marker-count span').html(markers.length);                  
          } else {
            console.log("Places request failed: "+status);
          }
        } // end callback

working fiddle

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