Question

将Google地图添加到我的Android应用中。尝试创建一个新的标记并将其添加到地图以及标记列表：

public void createMarkersFromList(){
    for(int i = 0; i < buildingList.size(); i++){
        double lat = Double.parseDouble(buildingList.get(i).getLatitude());
        double lng = Double.parseDouble(buildingList.get(i).getLongitude());
        LatLng position = new LatLng(lat, lng);
        String name = buildingList.get(i).getName();
        Marker m = fm.getMap().addMarker(new MarkerOptions()
                                            .position(position)
                                            .title(name));
        markers.add(m);
    }
}

但是，我在日志中遇到NullPointerException错误，应用程序崩溃了。我做错了什么？

11-24 23:13:51.171: E/dalvikvm(12071): The following issues were seen:
11-24 23:13:51.861: E/AndroidRuntime(12071): FATAL EXCEPTION: main
11-24 23:13:51.861: E/AndroidRuntime(12071): java.lang.NullPointerException: null reference
11-24 23:13:51.861: E/AndroidRuntime(12071):    at com.google.android.gms.internal.dm.e(Unknown Source)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at com.google.android.gms.maps.model.Marker.<init>(Unknown Source)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at com.example.uva_poops.ViewMap.createMarkersFromList(ViewMap.java:124)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at com.example.uva_poops.ViewMap$GetBuildingList.onPostExecute(ViewMap.java:114)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at com.example.uva_poops.ViewMap$GetBuildingList.onPostExecute(ViewMap.java:1)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at android.os.AsyncTask.finish(AsyncTask.java:631)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at android.os.AsyncTask.access$600(AsyncTask.java:177)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at android.os.Handler.dispatchMessage(Handler.java:99)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at android.os.Looper.loop(Looper.java:176)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at android.app.ActivityThread.main(ActivityThread.java:5279)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at java.lang.reflect.Method.invokeNative(Native Method)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at java.lang.reflect.Method.invoke(Method.java:511)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
11-24 23:13:51.861: E/AndroidRuntime(12071):    at dalvik.system.NativeStart.main(Native Method)

创建标记并将其添加到Google地图

0 个答案: