Google Maps API 设置 Button Click Listeners 错误

Question

我正在尝试在片段中设置 Google 地图，并且运行遇到了一些问题，试图让按钮正确收听。我有以下代码：

public DefaultMap extends android,.support.v4.app.Fragment implements OnMapReadyCallback {
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View v = inflater.inflate(R.layout.map_fragment, container, false);

        MapsInitializer.initialize(getActivity());

        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        mMapFragment = new SupportMapFragment() {
            @Override
            public void onActivityCreated(Bundle savedInstanceState) {
                super.onActivityCreated(savedInstanceState);
                mMap = mMapFragment.getMap();
                if (mMap != null) {

                }
            }
        };

        mMapFragment.getMapAsync(this);
//        mAutocompleteView = (AutoCompleteTextView) findViewById(R.id.TFSearch);
//        mAutocompleteView.setAdapter(new PlaceAutocompleteAdapter(this, android.R.layout.simple_dropdown_item_1line));
        searchSetup(v);
        zoomSetup(v);
        setupMapType(v);
        return v;
    }
    //an example of one of the setup functions
    public void setupMapType(View view) {
        typeMapButton = (Button) view.findViewById(R.id.TFtype);
        typeMapButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mMap.getMapType() == GoogleMap.MAP_TYPE_NORMAL) {
                    mMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
                } else {
                    mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
                }
            }
        });
    }
}

map_fragment.xml的相关作品：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:tools="http://schemas.android.com/tools">
    <fragment xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:map="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/mapScreen"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        tools:context=".DefaultMap"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        />

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/map_type"
                android:id="@+id/TFtype"
                android:onClick="onTypeMap"
                tools:context=".DefaultMap"
                android:layout_marginRight="5dp" />
        </LinearLayout>

    </LinearLayout>

</FrameLayout>

点击按钮时出现以下错误（所有 4 个按钮都相同）：

 11-15 22:57:22.481 32523-32523/oose2017.place2b E/AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'int com.google.android.gms.maps.GoogleMap.getMapType()' on a null object reference
 11-15 22:57:22.481 32523-32523/myproject E/AndroidRuntime:     at myproject.interfaces.map.DefaultMap.onClick(DefaultMap.java:153)

有人知道我该如何解决这些问题吗？

Answer 1

使用 SupportMapFragment.newInstance() 获取 SupportMapFragment 的新实例，以便从片段中添加它，并从 DefaultMap 片段的 xml 中删除 android:name="com.google.android.gms.maps.SupportMapFragment"。

有关详细信息，请参阅以下教程：

SupportMapFragment problem when loding in Fragment class

Google Maps API 设置 Button Click Listeners 错误

Google Maps API setting Button Click Listeners wrong

android

google-maps

button

listener

onclicklistener