Question

我正在尝试在片段中显示mapview。地图视图从不显示。我错过了什么？

public class FriendsGroupMapFragment extends Fragment {

private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";

private String mParam1;
private String mParam2;

View friendsGroupMapFragmentView;
GoogleMap friendsMap;

private OnFragmentInteractionListener mListener;

public FriendsGroupMapFragment() {
    // Required empty public constructor
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    if (getArguments() != null) {
        mParam1 = getArguments().getString(ARG_PARAM1);
        mParam2 = getArguments().getString(ARG_PARAM2);
    }
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    Log.d("ON CREATEVIEW()","ON CREATEVIEW()");
    friendsGroupMapFragmentView = inflater.inflate(R.layout.fragment_friends_group_map, container, false);
    drawMap();

    return friendsGroupMapFragmentView;
}



@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    try {
        mListener = (OnFragmentInteractionListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement OnFragmentInteractionListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

@Override
public void onResume() {
    super.onResume();
    drawMap();
}

public interface OnFragmentInteractionListener {
    // TODO: Update argument type and name
    //public void onFragmentInteraction(Uri uri);
}

public void drawMap(){

    Log.d("drawMap","drawMap");
    if(friendsMap != null){
        MapsInitializer.initialize(getActivity());
        friendsMap = ((MapView)friendsGroupMapFragmentView.findViewById(R.id.mapfriends)).getMap();
        if(friendsMap == null){
            Log.d("NULL","NULL");
        }

        LatLng chennai = new LatLng(13.0839,80.2700);
        friendsMap.moveCamera(CameraUpdateFactory.newLatLng(chennai));
    }

}

}

我的xml文件：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.test.mobile.activity.FriendsGroupMapFragment">



<com.google.android.gms.maps.MapView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/mapfriends"/>

</FrameLayout>

我的清单：

<?xml version="1.0" encoding="utf-8"?>

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.test.mobile.activity.LoginActivity"
        android:label="@string/app_name"
        android:screenOrientation="portrait"
        android:configChanges="orientation|keyboardHidden">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <activity
        android:name="com.test.mobile.activity.MainActivity"
        android:label="@string/title_activity_main"
        android:screenOrientation="portrait"
        android:configChanges="orientation|keyboardHidden">
    </activity>
    <meta-data
        android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version" />
    <meta-data
        android:name="com.google.android.maps.v2.API_KEY"
        android:value="my_apikey_value"/>
</application>

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="com.example.map.permission.MAPS_RECEIVE"/>

Answer 1

我认为问题出在您的drawMap：

中

public void drawMap(){

    Log.d("drawMap","drawMap");
    if(friendsMap != null){
        MapsInitializer.initialize(getActivity());
        friendsMap = ((MapView)friendsGroupMapFragmentView.findViewById(R.id.mapfriends)).getMap();
        if(friendsMap == null){
            Log.d("NULL","NULL");
        }

        LatLng chennai = new LatLng(13.0839,80.2700);
        friendsMap.moveCamera(CameraUpdateFactory.newLatLng(chennai));
    }
}

只有在创建了地图时才在这里创建地图:) 尝试更改为

if(friendsMap == null)
{
    ....
}

修改

我完全错过了你使用MapView而不是MapFragment。

使用MapView，您需要将所有片段生命周期事件（onCreate，onDestroy，onResume等）传递给MapView。见this section of docs

我唯一要提到的是，由于你在片段内膨胀MapView，你需要在MapView内拨打onCreate onCreateView()：

@Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate the layout for this fragment Log.d("ON CREATEVIEW()","ON CREATEVIEW()"); friendsGroupMapFragmentView = inflater.inflate(R.layout.fragment_friends_group_map, container, false); this.mapView = (MapView)friendsGroupMapFragmentView.findViewById(R.id.mapfriends); this.mapView.onCreate(savedInstanceState); drawMap(); return friendsGroupMapFragmentView; } @Override public View onResume() { this.mapView.onResume(); ..... }

等等

android：地图没有显示

1 个答案: