我正在使用Google Maps Android API Utility Library在我的应用中启用群集。当五个或更多标记共同定位时,将创建一个集群:
四个或更少的类似共处标记不会创建一个集群:
这是设计还是我做错了,因为我的地图有2个,3个或4个标记明显重叠,但不会形成群集?
用于演示问题的代码:
地图布局:
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.google.android.gms.maps.SupportMapFragment"/>
活动:
package com.example.android.clusteringminima;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.maps.android.clustering.ClusterItem;
import com.google.maps.android.clustering.ClusterManager;
public class ClusteringMinimaTest extends FragmentActivity {
private GoogleMap mMap;
private ClusterManager<Place> mClusterManager;
public class Place implements ClusterItem {
private final LatLng mPosition;
public Place(double lat, double lng) {
mPosition = new LatLng(lat, lng);
}
@Override
public LatLng getPosition() {
return mPosition;
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
setUpMapIfNeeded();
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
}
private void setUpMapIfNeeded() {
if (mMap != null) {
return;
}
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
if (mMap != null) {
mClusterManager = new ClusterManager<Place>(this, mMap);
mMap.setOnCameraChangeListener(mClusterManager);
// Cluster of 4 or 5
mClusterManager.addItem(new Place(51.471524, -0.454280));
mClusterManager.addItem(new Place(51.471311, -0.452257));
mClusterManager.addItem(new Place(51.471510, -0.453514));
mClusterManager.addItem(new Place(51.471710, -0.453714));
// Remove this item to create a group of four
mClusterManager.addItem(new Place(51.471810, -0.453714));
// Cluster of 9 (depending on zoom level)
mClusterManager.addItem(new Place(51.517399, -0.177480));
mClusterManager.addItem(new Place(51.509899, -0.134180));
mClusterManager.addItem(new Place(51.495708, -0.144370));
mClusterManager.addItem(new Place(51.496112, -0.144162));
mClusterManager.addItem(new Place(51.512458, -0.118644));
mClusterManager.addItem(new Place(51.518600, -0.081300));
mClusterManager.addItem(new Place(51.530449, -0.125480));
mClusterManager.addItem(new Place(51.513008, -0.088430));
mClusterManager.addItem(new Place(51.505001, -0.086000));
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(51.5, -0.35), 9));
}
}
}
更新(原始答案发布3年后:D)
正如@schaenk所指出的,DefaultClusterRenderer
现在有setMinClusterSize(int)
方法做同样的事情。
原始答案
负责决定聚类/不聚类项目的类是DefaultClusterRenderer
。如果你看一下DefaultClusterRenderer#shouldRenderAsCluster()
方法 - 你会看到它只在簇的大小> MIN_CLUSTER_SIZE
时才开始聚类。在我们的情况下MIN_CLUSTER_SIZE = 4
。
遗憾的是,您无法动态更改此常量,因此您需要扩展DefaultClusterRenderer
类并覆盖shouldRenderAsCluster()
方法以提供您自己的逻辑:
class CustomRenderer<T extends ClusterItem> extends DefaultClusterRenderer<T>
{
public CustomRenderer(Context context, GoogleMap map, ClusterManager<T> clusterManager) {
super(context, map, clusterManager);
}
@Override
protected boolean shouldRenderAsCluster(Cluster<T> cluster) {
//start clustering if at least 2 items overlap
return cluster.getSize() > 1;
}
}
private void setUpMapIfNeeded() {
if (mMap != null) {
return;
}
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
if (mMap != null) {
mClusterManager = new ClusterManager<Place>(this, mMap);
mClusterManager.setRenderer(new CustomRenderer<Place>(this, mMap, mClusterManager));
........
}
}