在Google Maps API v3中使用MarkerClusterer限制縮放級別時出錯

Question

我使用此處找到的代碼：Integrating Spiderfier JS into markerClusterer V3 to explode multi-markers with exact same long/lat限制縮放級別，當單擊MarkerClusterer時創建的羣集包含位於同一位置的點。

活生生的例子是在這裏： http://www.adultlearnersfestival.com/newsite/yourarea/map.html

我在Firebug得到一個錯誤，但是：

Error: TypeError: markers is undefined 

，可以不知道是什麼導致了它。具體代碼是：

var minClusterZoom = 14; 
mc.setMaxZoom(minClusterZoom); 
gm.event.addListener(mc, 'clusterclick', function(cluster) { 
    map.fitBounds(cluster.getBounds()); // Fit the bounds of the cluster clicked on 
    if(map.getZoom() > minClusterZoom+1) // If zoomed in past 15 (first level without clustering), zoom out to 15 
    map.setZoom(minClusterZoom+1); 
}); 

任何幫助非常感謝。 - Tom

Answer 1

我採取了不同的方法這裏建議：markerClusterer on click zoom和編輯MarkerClusterer源如下

從這個

/** 
* Triggers the clusterclick event and zoom's if the option is set. 
*/ 
ClusterIcon.prototype.triggerClusterClick = function() { 
    var markerClusterer = this.cluster_.getMarkerClusterer(); 

    // Trigger the clusterclick event. 
    google.maps.event.trigger(markerClusterer, 'clusterclick', this.cluster_); 

    if (markerClusterer.isZoomOnClick()) { 
    // Zoom into the cluster. 
    this.map_.fitBounds(this.cluster_.getBounds()); 
    } 
}; 

這個

/** 
* Triggers the clusterclick event and zoom's if the option is set. 
*/ 
ClusterIcon.prototype.triggerClusterClick = function() { 
    var markerClusterer = this.cluster_.getMarkerClusterer(); 

    // Trigger the clusterclick event. 
    google.maps.event.trigger(markerClusterer, 'clusterclick', this.cluster_); 

    if (markerClusterer.isZoomOnClick()) { 
    // Zoom into the cluster. 
    this.map_.fitBounds(this.cluster_.getBounds()); 

    // modified zoom in function 
     if(this.map_.getZoom() > markerClusterer.getMaxZoom()+1) 
      this.map_.setZoom(markerClusterer.getMaxZoom()+1); 
    } 
}; 

Answer 2

看起來像MarkerClusterer中的一個錯誤。裏面的for循環這個功能，標記是不確定的，這意味着this.getMarkers（）的返回undefined，在我看來就像它是錯誤的：

/** 
* Returns the bounds of the cluster. 
* 
* @return {google.maps.LatLngBounds} the cluster bounds. 
*/ 
Cluster.prototype.getBounds = function() { 
    var bounds = new google.maps.LatLngBounds(this.center_, this.center_); 
    var markers = this.getMarkers(); 
    for (var i = 0, marker; marker = markers[i]; i++) { 
    bounds.extend(marker.getPosition()); 
    } 
    return bounds; 
}; 

大概應該是這樣的（未測試）：

/** 
* Returns the bounds of the cluster. 
* 
* @return {google.maps.LatLngBounds} the cluster bounds. 
*/ 
Cluster.prototype.getBounds = function() { 
    var bounds = new google.maps.LatLngBounds(this.center_, this.center_); 
    var markers = this.getMarkers(); 
    if (markers && markers.length) 
    { 
    for (var i = 0; i < markers.length; i++) { 
     bounds.extend(markers[i].getPosition()); 
    } 
    } 
    return bounds; 
}; 

Works using MarkerClustererPlus

Answer 3

我解決了改變這個問題：

Cluster.prototype.getBounds = function() { 
    var bounds = new google.maps.LatLngBounds(this.center_, this.center_); 
    var markers = this.getMarkers(); 
    for (var i = 0, marker; marker = markers[i]; i++) { 
    bounds.extend(marker.getPosition()); 
    } 
    return bounds; 
}; 

這樣：

Cluster.prototype.getBounds = function() { 
    var bounds = new google.maps.LatLngBounds(this.center_, this.center_); 
    var markers = this.getMarkers(); 
    var minZoom =10 
    mc.setMaxZoom(minZoom);//The maximum zoom level that a marker can be part of a cluster 
    for (var i = 0; i < markers.length; i++) { 
    bounds.extend(marker.getPosition());//Extends this bounds to contain the given point. 
    } 
    if(map.getZoom() > minZoom+1){// If zoomed in past 11, the first level without clustering, zoom out to 11. 
    map.setZoom(minZoom+1); 
    } 
    return bounds; 

};