我正在开发一个使用 v2 MapFragment 的应用程序，但我遇到了非常奇怪的行为。我已经创建了一个 MapFragment 的子类来处理一些自定义行为(处理 Marker、调整菜单选项等)，并且在第一次加载时一切正常。然后我将一个新 fragment 嵌入到我的 Activity 中，将自定义 MapFragment 推送到后台堆栈。但是，当我从后台返回 map 时，事情变得很奇怪；平移 map 变得极度滞后(我们说的是 ~1 FPS)，无论是手动拖动/缩放还是点击图钉引起的动画。 然后，如果我与溢出菜单的任何部分进行交互，即使只是打开它并再次关闭它，延迟也会立即消失。似乎没有其他方法可以解决它(除了关闭/重新打开应用程序)；与非溢出菜单项和抽屉导航交互无济于事。我从来没有见过这样的事情，也找不到以前描述过类似问题的人。欢迎任何想法、建议和/或修复。

在他们被问到之前回答几个问题:

• 是的，我正在调用我覆盖的所有生命周期方法的 super 版本(onCreate()、onCreateView() [I我还返回 super 返回的内容]，以及 onDestroyView())。
• 据我所知，我正在正确清理 map 。每次刷新图钉时，我都会在每个图钉上调用 remove()，然后在 map 本身上调用 clean()，我在 onDestroyView() 还有。

最后，作为引用，这是添加新 fragment 的代码:

getFragmentManager().beginTransaction().replace(R.id.main_content_container, new JoinGroupFragment()).addToBackStack(null).commit();

当我完成它时，我只需调用:

getFragmentManager().popBackStack();

编辑:我不确定它会有多大帮助，但这是自定义 MapFragment:

public class CustomMapFragment extends MapFragment {

    private static final String DIALOG_TAG = "CUSTOM_MAP_FRAGMENT_DIALOG";
    private static final int DEFAULT_ZOOM = 14;
    private static final int MARKER_ZOOM = 15;
    private static final int DEFAULT_PADDING = 80;
    private static final int ORANGE_THRESHOLD_MINUTES = 7;
    private static final int BLUE_THRESHOLD_MINUTES = 20;

    public static final String KEY_GROUP_NAME = "GROUP_NAME";
    public static final String KEY_GROUP_ID = "GROUP_ID";

    private TextView mGroupNameOverlay;
    private GoogleMap mMap;
    private ArrayList<Marker> mMarkers;
    private Marker mSelectedMarker;
    private ArrayList<Group> mAllGroups;
    private Group mCurrentGroup;
    private ArrayList<Location> mAllLocations;
    private boolean mMapReady;
    private String mUsername;
    private boolean mCenterOnUser;

    public CustomMapFragment() {

    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);

        mMarkers = new ArrayList<>();
        mAllLocations = new ArrayList<>();

        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getActivity());
        mUsername = prefs.getString(PreferenceUtils.KEY_USERNAME, null);
        mCenterOnUser = prefs.getBoolean(PreferenceUtils.KEY_CENTER_ON_ME, false);
        mSelectedMarker = null;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        ViewGroup view = (ViewGroup)super.onCreateView(inflater, container, savedInstanceState);

        if (view != null) {
            // View should never be null; MapFragments have a FrameLayout as their top level parent
            mGroupNameOverlay = (TextView)inflater.inflate(R.layout.group_name_overlay, view, false);
            view.addView(mGroupNameOverlay);
        }

        Bundle results = ((MainActivity)getActivity()).getFragmentResults();
        if (results != null) {
            String name = results.getString(KEY_GROUP_NAME);
            String id = results.getString(KEY_GROUP_ID);
            if (!StringUtils.isNullOrEmpty(name) && !StringUtils.isNullOrEmpty(id)) {
                mCurrentGroup = new Group(name, id);
                mAllGroups.add(mCurrentGroup);
            }
        }

        if (mCurrentGroup != null) {
            updateGroupNameOverlay(mCurrentGroup.getGroupName());
        }

        getMapAsync(new OnMapReadyCallback() {
            @Override
            public void onMapReady(GoogleMap googleMap) {
                mMap = googleMap;
                mMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
                    @Override
                    public boolean onMarkerClick(Marker marker) {
                        mSelectedMarker = marker;
                        getActivity().invalidateOptionsMenu();
                        return false;
                    }
                });
                mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
                    @Override
                    public void onMapClick(LatLng latLng) {
                        mSelectedMarker = null;
                        getActivity().invalidateOptionsMenu();
                    }
                });
                populateMap(true, false);
            }
        });

        GetGroupsRequest request = new GetGroupsRequest();
        request.setListener(new GetGroupsRequestListener());
        RequestProcessor.getInstance(getActivity()).queueRequest(request);

        return view;
    }

    @Override
    public void onDestroyView() {
        mSelectedMarker = null;
        for (Marker marker : mMarkers) {
            marker.remove();
        }
        mMarkers.clear();
        mMap.clear();
        mMap = null;
        mMapReady = false;
        super.onDestroyView();
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        if (mSelectedMarker == null) {
            inflater.inflate(R.menu.menu_map, menu);
        }
        else {
            inflater.inflate(R.menu.menu_marker, menu);
        }
        super.onCreateOptionsMenu(menu, inflater);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.map_menu_refresh_pins:
                performLocationsRequest(false);
                return true;
            case R.id.map_menu_recenter_zoom:
                populateMap(true, true);
                return true;
            case R.id.map_menu_select_group:
                DialogFragment selectDialog = new DialogFragment() {

                    @Override
                    public Dialog onCreateDialog(Bundle savedInstanceState) {
                        String[] groups = new String[mAllGroups.size()];
                        for (int i = 0; i < groups.length; i++) {
                            groups[i] = mAllGroups.get(i).getGroupName();
                        }
                        return new AlertDialog.Builder(getActivity())
                                .setItems(groups, new DialogInterface.OnClickListener() {
                                    @Override
                                    public void onClick(DialogInterface dialog, int which) {
                                        if (!mAllGroups.get(which).equals(mCurrentGroup)) {
                                            mCurrentGroup = mAllGroups.get(which);
                                            updateGroupNameOverlay(mCurrentGroup.getGroupName());
                                            performLocationsRequest(true);
                                        }
                                    }
                                })
                                .create();
                    }
                };
                selectDialog.show(getFragmentManager(), DIALOG_TAG);
                return true;
            case R.id.map_menu_join_group:
                getFragmentManager().beginTransaction().replace(R.id.main_content_container, new JoinGroupFragment()).addToBackStack(null).commit();
                return true;
            case R.id.map_menu_create_group:
                CreateDialogFragment createDialog = new CreateDialogFragment();
                createDialog.show(getFragmentManager(), DIALOG_TAG);
                return true;
            case R.id.map_marker_zoom:
                if (mSelectedMarker != null) {
                    mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(mSelectedMarker.getPosition(), MARKER_ZOOM));
                }
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    private void performLocationsRequest(boolean autoZoom) {
        GetLocationsRequest request = new GetLocationsRequest(mCurrentGroup.getGroupId());
        request.setListener(new GetLocationsRequestListener(autoZoom));
        RequestProcessor.getInstance(getActivity()).queueRequest(request);
    }

    private void updateGroupNameOverlay(final String groupName) {
        if (mGroupNameOverlay != null) {
            getActivity().runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    if (groupName == null) {
                        mGroupNameOverlay.setText(R.string.map_group_overlay_no_group);
                    }
                    else {
                        mGroupNameOverlay.setText(getString(R.string.map_group_overlay_group, groupName));
                    }
                }
            });
        }
    }

    private void populateMap(boolean zoom, boolean animate) {
        if (!mMapReady) {
            mMapReady = true;
        }
        else {
            CameraUpdate update = null;
            mSelectedMarker = null;
            for (Marker marker : mMarkers) {
                marker.remove();
            }
            mMarkers.clear();
            mMap.clear();
            if (mAllLocations.size() == 1) {
                Location location = mAllLocations.get(0);
                mMarkers.add(addMarker(location));
                update = CameraUpdateFactory.newLatLngZoom(new LatLng(location.getLatitude(), location.getLongitude()), DEFAULT_ZOOM);
            }
            else if (mAllLocations.size() > 1) {
                LatLngBounds.Builder builder = new LatLngBounds.Builder();
                for (Location location : mAllLocations) {
                    mMarkers.add(addMarker(location));
                    if (mCenterOnUser) {
                        if (location.getUsername().equals(mUsername)) {
                            update = CameraUpdateFactory.newLatLngZoom(new LatLng(location.getLatitude(), location.getLongitude()), DEFAULT_ZOOM);
                        }
                    }
                    else {
                        builder.include(new LatLng(location.getLatitude(), location.getLongitude()));
                    }
                }
                if (!mCenterOnUser) {
                    update = CameraUpdateFactory.newLatLngBounds(builder.build(), DEFAULT_PADDING);
                }
            }

            if (update != null && zoom) {
                if (animate) {
                    mMap.animateCamera(update);
                }
                else {
                    mMap.moveCamera(update);
                }
            }
        }
    }

    private Marker addMarker(Location location) {
        String timestamp;
        long minutesOld = (new Date().getTime() - location.getLastReported()) / 60000;
        float hue = BitmapDescriptorFactory.HUE_RED;
        if (minutesOld < 1) {
            timestamp = getString(R.string.map_timestamp_just_now);
        }
        else if (minutesOld < 2) {
            timestamp = getString(R.string.map_timestamp_one_minute);
        }
        else {
            timestamp = getString(R.string.map_timestamp_n_minutes, minutesOld);
            if (minutesOld >= ORANGE_THRESHOLD_MINUTES) {
                hue = BitmapDescriptorFactory.HUE_ORANGE;
            }
            if (minutesOld >= BLUE_THRESHOLD_MINUTES) {
                hue = BitmapDescriptorFactory.HUE_BLUE;
            }
        }
        LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
        return mMap.addMarker(new MarkerOptions()
                .position(latLng)
                .icon(BitmapDescriptorFactory.defaultMarker(hue))
                .title(location.getUsername())
                .snippet(timestamp));
    }

    private class GetGroupsRequestListener extends RequestListener<GetGroupsResponse> {

        public GetGroupsRequestListener() {
            super(getActivity());
        }

        @Override
        protected void onRequestComplete(GetGroupsResponse response) {
            mAllGroups = response.getGroups();
            if (mAllGroups.size() > 0) {
                if (mCurrentGroup == null) {
                    mCurrentGroup = mAllGroups.get(0);
                    updateGroupNameOverlay(mCurrentGroup.getGroupName());
                }
                performLocationsRequest(true);
            }
        }
    }

    private class GetLocationsRequestListener extends RequestListener<GetLocationsResponse> {

        private boolean mmAutoZoom;

        public GetLocationsRequestListener(boolean autoZoom) {
            super(getActivity());
            mmAutoZoom = autoZoom;
        }

        @Override
        protected void onRequestComplete(GetLocationsResponse response) {
            mAllLocations = response.getLocations();
            getActivity().runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    populateMap(mmAutoZoom, false);
                }
            });
        }
    }
}

附言我意识到劫持 View 创建并以这种方式注入(inject)我自己的覆盖层可能不是最佳做法，但就其值(value)而言，我尝试将该部分注释掉但它没有解决问题，所以我很怀疑它是相关的。

最佳答案

我遇到过类似的问题。假设我有带有子 SupportMapFragment 的 FragmentA。通过抽屉导航菜单，我调用了一个要显示的对话框。此时 FragmentA 中的子 map 进入某种“背景模式”——它大约每秒更新两次(我在这张 map 上有动画标记，所以这种行为对我来说是众所周知的)。这种“背景”模式是通过显示任何带有覆盖的元素来打开的，例如。对话框或 AppBar 菜单，并在该元素隐藏时关闭。

在对话框中我有项目列表，点击时开始 fragment 替换事务。此时 FragmentA 正在被 FragmentB 取代。这是 OnClickListener 的代码 fragment :

final SmartFragment fragment = new SmartFragment();
FragmentManager supportFragmentManager = getActivity().getSupportFragmentManager();
supportFragmentManager
        .beginTransaction()
        .replace(R.id.fragment_container, fragment, SmartFragment.FRAGMENT_TAG)
        .addToBackStack(null)
        .commit();
dismiss();

但是在我从后台返回到 FragmentA 后，保留的 map 仍然处于“背景模式”，即使对话框不再存在。在事务之前移动 dissmiss() 语句无济于事，它看起来就像对话框在执行所有代码之前不会被关闭。因此，唯一合理的解决方案(除了直接在 map fragment 上打开“背景模式”，我找不到如何做)是延迟 fragment 事务，直到对话框真正被关闭。正如我之前假设的那样，只有当 OnClick(它是对话框的一部分)中的所有代码都被执行时才会发生，所以我们需要让事务不在它被声明的实例中完成，而是稍后，将它放在 Runnable 中:

dismiss();
final SmartFragment fragment = new SmartFragment();
Handler handler = new Handler();
final FragmentManager supportFragmentManager = getActivity().getSupportFragmentManager();
handler.post(new Runnable() {
    @Override
    public void run() {
        supportFragmentManager
                .beginTransaction()
                .replace(R.id.fragment_container, fragment, StopsSmartFragment.FRAGMENT_TAG)
                .addToBackStack(null)
                .commit();
    }
});

为此，我们需要将我们的 fragment 和 supportFragmentManager 设置为最终的。现在一切正常， map 的“后台模式”已关闭，如果您从后台返回到 FragmentA， map 将正常工作。

如果有人知道如何直接关闭 map fragment 中的“背景模式”，请告诉我，我很乐意听到。

关于java - Google Maps v2 MapFragment 在从后台返回时非常滞后，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27978188/