地图碎片无法片段刷新后进行修改 [英] Map Fragment couldn't be modified after Fragment Reload
问题描述
-
我有一个的活动与抽屉式导航和 HomeFragment
HomeFragment 包含两个嵌套的片段（子片段）： SupportMapFragment 和 ActionFragment
HomeFragment contains two nested fragments (child fragments): SupportMapFragment and ActionFragment.
我宣布GoogleMap对象的 SMAP 的作为静态的 HomeFragment ，因此它可以访问和修改嵌套的片段 ActionFragment
I declare the GoogleMap object sMap as static in HomeFragment, so it can be accessed and modified by the nested fragment ActionFragment.
一切正常，在第一次运行的罚款。地图可以从内部的 ActionFragment 进行操作。但是当HomeFragment除去和重新装载在稍后的时间点，在地图上只能从HomeFragment（父片段）改性而不是从ActionFragment（嵌套片段）了。
Everything works fine in the first run. The map can be manipulated from within the ActionFragment. But when the HomeFragment is removed and reloaded at a later point of time, the map could only be modified from the HomeFragment (parent fragment) and not from the ActionFragment (nested fragment) anymore.
我没能理解为什么一些在一审时的作品片段重新加载不起作用。下面是我一直保持到最低限度更容易理解codeS。
I am failing to understand why something that works in the first instance doesn't work when the fragment is reloaded. Below are the codes which I have kept to minimum for easier understanding.
HomeFragment.java （家长片段）
public class HomeFragment extends Fragment {
private static GoogleMap sMap;
public static GoogleMap getMap() {
return sMap;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate layout
return inflater.inflate(R.layout.f_home, container, false);
}
@Override
public void onActivityCreated(Bundle savedInstanceState){
super.onActivityCreated(savedInstanceState);
// Obtain the GoogleMap object
try {
if (sMap == null) {
sMap = ((SupportMapFragment) getActivity().getSupportFragmentManager()
.findFragmentById(R.id.home_map)).getMap();
}
} catch (Exception e) {
e.printStackTrace();
}
// Load child fragment
if (savedInstanceState == null) {
Fragment _actionFragment = new ActionFragment();
FragmentTransaction _ft = getChildFragmentManager().beginTransaction();
_ft.replace(R.id.action_container_bottom, _actionFragment);
_ft.commit();
}
}
@Override
public void onDestroyView(){
super.onDestroyView();
// Remove the map fragment to prevent errors on the next load
if(sMap != null){
try {
getActivity().getSupportFragmentManager()
.beginTransaction()
.remove(getActivity().getSupportFragmentManager()
.findFragmentById(R.id.home_map))
.commit();
sMap = null;
} catch (Exception e){}
}
}
}
f_home.xml （父片段的布局）
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment
android:id="@+id/home_map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<FrameLayout
android:id="@+id/action_container_bottom"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true" />
</RelativeLayout>
ActionFragment.java （嵌套或子片段）
public class ActionFragment extends Fragment {
private static GoogleMap sMap = HomeFragment.getMap();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.f_action, container, false);
}
@Override
public void onActivityCreated(Bundle savedInstanceState){
super.onActivityCreated(savedInstanceState);
// check if map is created successfully or not
if (sMap != null) {
sMap.clear();
sMap.setPadding(0, 0, 0, 300);
sMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
sMap.setBuildingsEnabled(false);
sMap.setMyLocationEnabled(false);
sMap.getUiSettings().setRotateGesturesEnabled(false);
sMap.getUiSettings().setTiltGesturesEnabled(false);
sMap.getUiSettings().setZoomControlsEnabled(false);
sMap.moveCamera(CameraUpdateFactory.zoomTo(12));
}
}
}
任何帮助将是因为我这个挣扎了很长一段时间非常AP preciated。谢谢！
Any help would be immensely appreciated as I am struggling with this for a long time. Thank you!
推荐答案
糟糕的设计。
这是错误的，保持静止无功用于存储地图参考。假设你有一个里面有2 HomeFragment或HomeFragment几项活动。它不会工作。
Bad design. It's wrong to keep static var for storing reference to a map. Suppose you have two HomeFragment or several activities that have HomeFragment inside. It won't work.
我认为你应该使用标签来发现碎片。或者更好的创造活动的一些接口，实现您的片段之间的通信。反正你不能使用静态字段为你做的方式映射。
I think you should use tags to find fragments. Or better create some interface in activity that implements communication between your fragments. Anyway you must not use static field for a map in a way you do.
您可以使用此code：
You can use this code:
((SupportMapFragment) getActivity().getSupportFragmentManager()
.findFragmentById(R.id.home_map)).getMap();
让每一个你需要时间映射。
to get map every time you need.
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