谷歌地图没有显示在安卓活动中？

Question

在我的 android 应用程序中，我想要一个 MainActivity，其中有一个占据整个屏幕的谷歌地图。

我的问题是谷歌地图不显示地图，只有左下角的谷歌标志：

以下是应显示地图的主要活动的相关部分：

public class MainActivity extends AppCompatActivity implements OnMapReadyCallback,
        NavigationView.OnNavigationItemSelectedListener {

    private GoogleMap mMap;

    private FragmentManager mFragmentManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

        setupLayout();

        mFragmentManager = getSupportFragmentManager();
    }

    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        // Add a marker in Sydney and move the camera
        LatLng sydney = new LatLng(-34, 151);
        mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
    }

这是包含谷歌地图片段的主要活动内容的 xml：

<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/map"
          android:name="com.google.android.gms.maps.SupportMapFragment"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          tools:context="com.purringcat.stray.view.activity.MainActivity"/>

这是清单文件：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.purringcat.stray">

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

    <!--
         The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
         Google Maps Android API v2, but you must specify either coarse or fine
         location permissions for the 'MyLocation' functionality. 
    -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

    <application
        android:name=".Stray"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".view.activity.MainActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <activity
            android:name=".view.activity.LoginActivity"
            android:label="@string/title_activity_login"
            android:theme="@style/AppTheme.NoActionBar">
        </activity>
        <activity android:name=".view.activity.SignUpActivity">
        </activity>
        <!--
             The API key for Google Maps-based APIs is defined as a string resource.
             (See the file "res/values/google_maps_api.xml").
             Note that the API key is linked to the encryption key used to sign the APK.
             You need a different API key for each encryption key, including the release key that is used to
             sign the APK for publishing.
             You can define the keys for the debug and release targets in src/debug/ and src/release/. 
        -->
        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key"/>

    </application>

</manifest>

Answer 1

您需要从 google 控制台为您的项目启用 google map api。您还需要从控制台下载 json 文件。

1. 进入谷歌控制台

2. 点击你的项目。

3. 单击左侧菜单面板中的库部分。见下图

4. 在谷歌地图api中，点击谷歌地图android api

5. 比启用那个。

6. 现在转到firebase 控制台

7. 单击您的项目并转到项目设置并下载 json 文件。

8. 在您的应用程序中添加该 json 文件。