在布局 xml 中膨胀类片段时出错

Question

我目前正在尝试制作一个具有谷歌地图视图的简单应用程序。目前，我的 xml 布局中使用的片段类出现错误。错误的 logcat、.java 代码和 XML 都包括在内。我一直在关注教程here 我也尝试了here 和here 的解决方案，但没有成功：

*使用更新的文件进行编辑

错误日志

03-03 13:10:31.465: E/AndroidRuntime(18671): FATAL EXCEPTION: main
03-03 13:10:31.465: E/AndroidRuntime(18671): java.lang.RuntimeException: Unable to start activity ComponentInfo{io.github.ukopenlexingtonseniordesign.busalert/io.github.ukopenlexingtonseniordesign.busalert.MainActivity}: android.view.InflateException: Binary XML file line #2: Error inflating class fragment
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1968)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1993)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.ActivityThread.access$600(ActivityThread.java:127)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1159)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.os.Handler.dispatchMessage(Handler.java:99)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.os.Looper.loop(Looper.java:137)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.ActivityThread.main(ActivityThread.java:4507)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at java.lang.reflect.Method.invokeNative(Native Method)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at java.lang.reflect.Method.invoke(Method.java:511)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at dalvik.system.NativeStart.main(Native Method)
03-03 13:10:31.465: E/AndroidRuntime(18671): Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class fragment
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:697)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.view.LayoutInflater.inflate(LayoutInflater.java:466)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:280)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.Activity.setContentView(Activity.java:1835)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at io.github.ukopenlexingtonseniordesign.busalert.MainActivity.onCreate(MainActivity.java:13)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.Activity.performCreate(Activity.java:4465)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1052)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1932)
03-03 13:10:31.465: E/AndroidRuntime(18671):    ... 11 more
03-03 13:10:31.465: E/AndroidRuntime(18671): Caused by: android.app.Fragment$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
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.Fragment.instantiate(Fragment.java:581)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.Fragment.instantiate(Fragment.java:549)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.Activity.onCreateView(Activity.java:4235)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:673)
03-03 13:10:31.465: E/AndroidRuntime(18671):    ... 20 more
03-03 13:10:31.465: E/AndroidRuntime(18671): Caused by: java.lang.ClassNotFoundException: com.google.android.gms.maps.MapFragment
03-03 13:10:31.465: E/AndroidRuntime(18671):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
03-03 13:10:31.465: E/AndroidRuntime(18671):    at android.app.Fragment.instantiate(Fragment.java:571)
03-03 13:10:31.465: E/AndroidRuntime(18671):    ... 23 more

MainActivity.java：

package io.github.ukopenlexingtonseniordesign.busalert;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.Menu;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
} 

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"/>

AndroidManifest.xml：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="io.github.ukopenlexingtonseniordesign.busalert"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="12"
        android:targetSdkVersion="19" />

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

    <permission
        android:name="io.github.ukopenlexingtonseniordesign.busalert.permission.MAPS_RECEIVE"
        android:protectionLevel="signature" />

    <uses-permission android:name="io.github.ukopenlexingtonseniordesign.busalert.permission.MAPS_RECEIVE" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="io.github.ukopenlexingtonseniordesign.busalert.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="AIzaSyCjGTI1myam9dyf6Cay1h379drj98nAjSM"/>

        <uses-library android:name="com.google.android.maps" />

        <meta-data
            android:name="com.google.android.gms.version"
            android:value="4242000" />

    </application>

</manifest>

由于另一个错误，清单中的“android:value="4242000"” 行是一个快速修复。感谢您抽出宝贵时间，希望有人能找出问题所在

Answer 1

改变这个

android:name="com.google.android.gms.maps.MapFragment"/>

到

android:name="com.google.android.gms.maps.SupportMapFragment"/>

你有

public class MainActivity extends FragmentActivity 

FragmentActivity 是基于支持的片段的基本活动。我猜你想支持 11 级及以下的地图片段 api，在这种情况下你需要使用SupportMapFragment。

Answer 2

android:id="@+id/@android:id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"/>