Java 使用ClusterManager时如何更新地图上的标记

我正试图用服务器上更新的数据更新我的地图，但我不知道如何从地图中删除旧项目（标记和群集-使用ClusterManager）

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

我有一个BroadcastReceiver，当有新的数据时，它会产生意图。我尝试过这样的方法：（但它会给我不支持的操作异常“…getMarkers（）.clear（）；”

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

我仅使用此功能将数据添加到地图

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

java.util.Collection userCollection=mClusterManager.getMarkerCollection（）.getMarkers（）；
ArrayList userList=新的ArrayList（userCollection）；
//现在userList是空的吗
for（标记：userList）{
marker.remove（）；
}
java.util.Collection userCollection2=mClusterManager.getClusterMarkerCollection（）.getMarkers（）；
ArrayList userList2=新的ArrayList（userCollection2）；
//现在userList2是空的吗
for（标记：userList2）{
marker.remove（）；
}
mClusterManager.addItems（LocationGetter.getReports（））；

我把全部时间都集中在ClusterManager上，所以我忘记了谷歌地图，特别是方法

clear（）

。我能够用这段代码解决问题：

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

mGoogleMap.clear();
mClusterManager.clearItems();  // calling just in case (may not be needed)
mClusterManager.addItems(LocationGetter.getReports());

---

根据

ClusterManager

，我们可以使用

mClusterManager.cluster（）；

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

此方法强制重新群集。您可能希望在添加后调用此方法 新项目

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

---

没有任何API通知集群项已更新。 但是您可以使用

clusterManager.removietem（）

+

clusterManager.addItem（）

强制更新项目

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

但您必须小心，因为您通常想要更新项目，因为它更改了一些影响渲染的属性。您需要使用一个自定义的

ClusterRenderer

，它支持此操作并覆盖

onClusterItemRendered（）

和/或

onClusterRendered（）

。使用onBefore变体不起作用，因为它们在创建标记时只被调用一次

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

---

您可以查看此GitHub问题

因为我的应用程序在创建地图后需要多次更新群集，我发现此工作流是删除和添加新群集的最佳解决方案：

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

mGoogleMap.clear();
mClusterManager.clear(); 
//Do work to add items to cluster
mClusterManager.addItems(yourItemsList);
//Finally 
mClusterManager.cluster(); 

---

这将迫使集群在修改内容后重新运行。

我想知道我怎么会遇到这个问题-我以前从未在地图节点上遇到过这样的问题

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

但是，这在我的示例应用程序的设置或更新映射逻辑中：

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

        mClusterManager = new ClusterManager<>(getContext(), googleMap);
        mClusterManager.setAnimation(false);
        mClusterManager.clearItems();

mClusterManager=newclustermanager（getContext（），googleMap）；
mClusterManager.setAnimation（false）；
mClusterManager.clearItems（）；

我从数据库中添加节点，然后从请求中添加一些节点，在我为构造函数添加空检查之前，这是一个明显的影响

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

i、 e.我应该这样做：

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

    if (mClusterManager == null)
            mClusterManager = new ClusterManager<>(getContext(), googleMap);
        mClusterManager.setAnimation(false);
        mClusterManager.clearItems();

if（mClusterManager==null）
mClusterManager=newclustermanager（getContext（），googleMap）；
mClusterManager.setAnimation（false）；
mClusterManager.clearItems（）；

---

我一定是复制并粘贴了这张地图，然后在上面浪费了半个小时。小心！

对我有用的不是地图

clear（）

，因为我还有一些其他标记没有连接到群集管理器

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

对我起作用的是：

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

this.clustermanger.clearItems()
this.clustermanager.clusterMakerCollection.clear()
//and I had to force a "cluster" again, force the clustermanager to take down all markers
this.clustermanager.cluster()

---

您应该能够做到：

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

val didUpdate = clusterManager?.updateItem(MyClusterItem(data))
clusterManager?.cluster()

确保clusterManager确实更新该项的关键在于重写扩展ClusterItem的类中的equals和hashcode，如：

java.util.Collection<Marker> userCollection = mClusterManager.getMarkerCollection().getMarkers();
            ArrayList<Marker> userList = new ArrayList<Marker>(userCollection);
            // now is userList empty
            for(Marker marker: userList){
                marker.remove();
            }

            java.util.Collection<Marker> userCollection2 = mClusterManager.getClusterMarkerCollection().getMarkers();
            ArrayList<Marker> userList2 = new ArrayList<Marker>(userCollection2);
            // now is userList2 empty
            for(Marker marker: userList2){
                marker.remove();
            }

            mClusterManager.addItems(LocationGetter.getReports());

fun getId(): String {
    return data.id
}
override fun equals(other: Any?): Boolean {
    return other is MyClusterItem && other.getId() == getId()
}
override fun hashCode(): Int {
    return getId().hashCode()
}

---

如果您得到空的

ArrayList

，请确保有正确的

ClusterManager

和

MarkerCollection（）

，我在这里使用了该方法。对我来说，这还不够。我正在删除和添加许多项。在操作完成后调用该方法解决了缺少刷新的问题：mClusterManager.cluster（）；-也许这对某些人有帮助。正如@plexus所说，需要调用cluster（）以确保集群得到更新。请小心使用.clear（）因为很多时候你需要放大/缩小地图才能正确更新。你能看看这篇文章吗？当使用多个项目时如何删除特定项目？你能看看这篇文章吗？？