Android SupportMapFragment.getMapAsync未調用OnMapReady

Question

我目前正在嘗試設置使用Google Maps片段的活動。這不是主要的啓動器活動，它在用戶認證時從另一個活動中調用。地圖顯示罰款並默認在遠處查看非洲，但它不會移動到OnMapReady函數中的指定位置，因爲該函數從未被調用過。我正在調用SupportMapFragment.getMapAsync，我相信我有正確的權限，所以我不確定問題可能是什麼。

這是我的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)); 
    } 
} 

這是我的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" /> 

這是我的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> 

這裏是我的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' 

同樣，問題是我的MapsActivity.java文件中的OnMapReady函數沒有被調用。我已通過將日誌記錄放入並且從未放到LogCat中對此進行了驗證。所以如果有人知道爲什麼會發生這種情況，我將不勝感激一些幫助。

Answer 1

我已經想通了！

顯然我需要實際調用startActivity函數來切換到一個新的活動，而不是僅僅設置內容視圖。

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

這是以前這個

setContentView(R.layout.activity_maps); 

這根本就不會調用MapsActivity.java文件。