Android项目：谷歌地图空白屏幕

Question

任何人都可以帮助我吗？我不知道为什么会这样。

照片：

我从手机上拍下照片。该应用程序正在运行但映射仍为空白。这是我的代码 MainActivity.java

package net.agusharyanto.petalokasi;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

public class MainActivity extends  Activity {
  static final LatLng RAGUNAN = new LatLng(-6.3039, 106.8267);
  static final LatLng TAMANMINI = new LatLng(-6.29436, 106.8859);
  private GoogleMap map;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
        .getMap();
    Marker ragunan = map.addMarker(new MarkerOptions().position(RAGUNAN)
        .title("Ragunan"));
    Marker tamanmini = map.addMarker(new MarkerOptions()
        .position(TAMANMINI)
        .title("Taman Mini")
        .snippet("Taman Mini itu Indah")
        .icon(BitmapDescriptorFactory
            .fromResource(R.drawable.ic_launcher)));

    // Move the camera instantly to hamburg with a zoom of 15.
    map.moveCamera(CameraUpdateFactory.newLatLngZoom(RAGUNAN, 15));

    // Zoom in, animating the camera.
    map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null);
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }

}

这是我的代码 activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
      <fragment xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/map"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:name="com.google.android.gms.maps.MapFragment"/>

这是 androidmanifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="net.agusharyanto.petalokasi"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="11"
    android:targetSdkVersion="17" />

<permission
    android:name="net.agusharyanto.petalokasi.permission.MAPS_RECEIVE"
    android:protectionLevel="signature" />

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

<uses-permission android:name="net.agusharyanto.petalokasi.permission.MAPS_RECEIVE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="net.agusharyanto.petalokasi.MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <meta-data
        android:name="com.google.android.maps.v2.API_KEY"
        android:value="AIzaSyBZXpNcSxRwv8KpJ6-kFGJsCKO-RNgc36Y" />
    <meta-data
        android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version" />
</application>

有人可以告诉我它为什么会发生并修复我的项目..