android - MapsDemo 活动中的运行时错误

Question

我正在使用Google 的本教程进行 MapsActivity，但由于某种原因，我没有得到所需的输出，应用程序崩溃了。

这是我正在使用的代码：

1. 清单.xml

   <uses-sdk
       android:minSdkVersion="15"
       android:targetSdkVersion="15" />
   
   <uses-permission android:name="android.permission.INTERNET" />
   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
   <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
   <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
   <uses-permission android:name="com.ajinkya.samplemapsdemo.permission.MAPS_RECEIVE" />
   <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
   
   <permission
       android:name="com.ajinkya.samplemapsdemo.permission.MAPS_RECEIVE"
       android:protectionLevel="signature" />
   
   <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" >
       <activity
           android:name="com.ajinkya.samplemapsdemo.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="blahblahblahkey" />
   </application>
   

2. 主要的.xml

   <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"/>
   

3. MainActivity.java

    package com.ajinkya.samplemapsdemo;
    import android.os.Bundle;
    import android.app.Activity;
    import android.view.Menu;
   
    public class MainActivity extends Activity {
   
   
    @Override
     protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.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;
   }}
   

根据谷歌的说法，应该显示地图，但没有发生。它给了我信息：

Unfortunately, samplemapsdemo has stopped.

这是日志：

08-01 18:30:21.671: D/ActivityThread(10657): setTargetHeapUtilization:0.25
08-01 18:30:21.671: D/ActivityThread(10657): setTargetHeapIdealFree:8388608
08-01 18:30:21.671: D/ActivityThread(10657): setTargetHeapConcurrentStart:2097152
08-01 18:30:21.741: W/dalvikvm(10657): threadid=1: thread exiting with uncaught exception (group=0x40a9f390)
08-01 18:31:36.581: D/ActivityThread(10705): setTargetHeapUtilization:0.25
08-01 18:31:36.581: D/ActivityThread(10705): setTargetHeapIdealFree:8388608
08-01 18:31:36.591: D/ActivityThread(10705): setTargetHeapConcurrentStart:2097152
08-01 18:31:36.801: W/dalvikvm(10705): threadid=1: thread exiting with uncaught exception (group=0x40a9f390)
08-01 18:31:36.831: E/AndroidRuntime(10705): FATAL EXCEPTION: main
08-01 18:31:36.831: E/AndroidRuntime(10705): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ajinkya.samplemapsdemo/com.ajinkya.samplemapsdemo.MainActivity}: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1959)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1984)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.ActivityThread.access$600(ActivityThread.java:126)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1150)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.os.Handler.dispatchMessage(Handler.java:99)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.os.Looper.loop(Looper.java:137)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.ActivityThread.main(ActivityThread.java:4456)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at java.lang.reflect.Method.invokeNative(Native Method)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at java.lang.reflect.Method.invoke(Method.java:511)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at dalvik.system.NativeStart.main(Native Method)
08-01 18:31:36.831: E/AndroidRuntime(10705): Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:697)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:739)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:251)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.Activity.setContentView(Activity.java:1835)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at com.ajinkya.samplemapsdemo.MainActivity.onCreate(MainActivity.java:15)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.Activity.performCreate(Activity.java:4465)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1923)
08-01 18:31:36.831: E/AndroidRuntime(10705):    ... 11 more
08-01 18:31:36.831: E/AndroidRuntime(10705): Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.google.android.gms.maps.MapFragment: make sure class name exists, is public, and has an empty constructor that is public
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.Fragment.instantiate(Fragment.java:581)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.Fragment.instantiate(Fragment.java:549)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.Activity.onCreateView(Activity.java:4235)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:673)
08-01 18:31:36.831: E/AndroidRuntime(10705):    ... 21 more
08-01 18:31:36.831: E/AndroidRuntime(10705): Caused by: java.lang.ClassNotFoundException: com.google.android.gms.maps.MapFragment
08-01 18:31:36.831: E/AndroidRuntime(10705):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
08-01 18:31:36.831: E/AndroidRuntime(10705):    at android.app.Fragment.instantiate(Fragment.java:571)
08-01 18:31:36.831: E/AndroidRuntime(10705):    ... 24 more

我相信这条线可能是所有问题的根本原因：

08-01 18:31:36.831: E/AndroidRuntime(10705): Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.google.android.gms.maps.MapFragment: make sure class name exists, is public, and has an empty constructor that is public

任何帮助，将不胜感激。