Android SupportMapFragment.getMapAsync 不调用 OnMapReady

Question

我目前正在尝试设置使用 Google 地图片段的活动。这不是主要的启动器活动，当用户进行身份验证时，它会从另一个活动中调用。该地图显示良好，默认为远距离查看非洲，但它不会移动到我在 OnMapReady 函数中指定的位置，因为该函数从未被调用。我正在调用 SupportMapFragment.getMapAsync，并且我相信我拥有正确的权限，所以我不确定问题可能是什么。

这是我的MapsActivity.java 文件。

package com.dizydev.wayfare;

import android.support.v4.app.FragmentActivity;
import android.os.Bundle;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(MapsActivity.this);
    }


    /**
     * 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));
    }
}

这是我的activity_maps.xml 文件。

<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.dizydev.wayfare.MapsActivity" />

这是我的AndroidManifests.xml 文件。

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

    <!-- Meta Data -->
    <meta-data
        android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version" />

    <!-- Permissions -->
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <!-- Features -->
    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <!--
             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" />

        <activity
            android:name=".SignInActivity"
            android:label="@string/title_activity_maps">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".MapsActivity"
            android:label="@string/title_activity_maps" />
    </application>
</manifest>

这是我的build.gradle 文件。

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    defaultConfig {
        applicationId "com.dizydev.wayfare"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.google.android.gms:play-services-maps:10.2.1'
    compile 'com.google.android.gms:play-services-auth:10.2.1'
    compile 'com.google.firebase:firebase-auth:10.2.1'
    compile 'com.google.firebase:firebase-database:10.2.1'
    compile 'com.google.android.gms:play-services-location:10.2.1'
    compile 'com.google.android.gms:play-services-ads:10.2.1'
    testCompile 'junit:junit:4.12'
}
apply plugin: 'com.google.gms.google-services'

同样，问题是我的 MapsActivity.java 文件中的 OnMapReady 函数没有被调用。我已经通过放入一个日志语句来验证这一点，并且它从未被放到 LogCat 中。因此，如果有人知道为什么会发生这种情况，我将不胜感激。

Answer 1

我想通了！

显然我需要实际调用 startActivity 函数来切换到一个新的活动，而不是仅仅设置内容视图。

startActivity(new Intent(SignInActivity.this, MapsActivity.class));

以前是这样的

setContentView(R.layout.activity_maps);

这根本不会调用 MapsActivity.java 文件。