谷歌地图没有显示在android活动中? [英] Google map not showing in android activity?

问题描述

在我的Android应用中，我想拥有一个MainActivity，其中的Google地图占据了整个屏幕.

In my android app I want to have a MainActivity with a google map occupying the entire screen.

我的问题是Google地图不显示地图，仅在左下角显示Google徽标:

My problem is that the google map does not display a map, only the google logo in the bottom left corner:

以下是应显示地图的主要活动的相关部分:

Here are the relevant parts of the main activity where the map should be displayed:

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));
    }

以下是包含Google地图片段的主要活动内容的xml:

Here is the xml for the content of the main activity which holds the google map fragment:

<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>

推荐答案

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

You need to enable google map api from google console for your project. And also you need to download json file from the console.

1.转到 Google控制台

1. Go to google console

2.点击您的项目.

3.单击左侧菜单面板中的库部分.见下图

1. 在google maps api中，单击 Google maps android api

比启用它.

现在转到 firebase控制台

单击您的项目并转到项目设置，然后下载json文件.

Click on your project and goto project settings and download the json file.

在您的应用程序中添加该json文件.

Add that json file in your application.

这篇关于谷歌地图没有显示在android活动中?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！