我想制作谷歌地图以在 Android 中使用，但我有一些问题。
显现：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.odv"
android:versionCode="1"
android:versionName="1.0" >
<uses-permission android:name="YOUR_PACKAGE_NAME.permission.MAPS_RECEIVE"
android:protectionLevel="signature"/>
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-permission android:name="your.package.name.permission.MAPS_RECEIVE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<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" />
<!-- Maps API needs OpenGL ES 2.0. -->
<uses-feature
android:glEsVersion="0x00020000"
android:required="true" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<!-- You must insert your own Google Maps for Android API v2 key in here. -->
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="AIzaSyCe29ye5iK83zx6rUBnCzulKCxf68nT-bs" />
<activity
android:name="com.example.odv.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>
</application>
</manifest>
主要 XML：
<?xml version="1.0" encoding="utf-8"?>
<!--
Copyright (C) 2012 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- This can go anywhere in your layout (see other demos for some examples).
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment"/>
-->
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment" />
主要活动：
package com.example.odv;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
public class MainActivity extends android.support.v4.app.FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
我想学安卓。我认为我有编程的算法智能，但我不知道如何开始学习编程。我没有很好的来源。
我写了这段代码，但我看不到地图。我只能看到白屏，无法打开地图。我能为此做些什么？
截屏