android - 膨胀 android.support.v4.app.FragmentTabHost 时出错

Question

我正在尝试创建一个可以与 android sdk 7 一起使用的日历应用程序，直到现在。我想使用标签来显示不同的日历视图（每周、每月、每日、议程）。因此，我需要为每个视图使用片段并使用支持库来实现向后兼容性。

这是我的 xml 布局文件

<android.support.v4.app.FragmentTabHost
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TabWidget
            android:id="@android:id/tabs"
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="0"/>

        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_weight="0"/>

        <FrameLayout
            android:id="@+id/realtabcontent"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"/>

    </LinearLayout>
</android.support.v4.app.FragmentTabHost>

这是随之而来的活动

package com.bmooredev.bpassistant;


import com.bmooredev.bpassistant.R;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTabHost;
import android.support.v4.app.FragmentTransaction;

public class EventsActivity extends FragmentActivity{
private WeekFragment FragWeek=new WeekFragment();
private MonthFragment FragMonth=new MonthFragment();
private DayFragment FragDay=new DayFragment();
private AgendaFragment FragAgenda=new AgendaFragment();

private int month;
private int day;
private int year;

 private FragmentTabHost mTabHost;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_events);

        mTabHost = (FragmentTabHost)findViewById(android.R.id.tabhost);
        mTabHost.setup(this, getSupportFragmentManager(), R.id.realtabcontent);

        mTabHost.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),
                WeekFragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),
                MonthFragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),
                DayFragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),
                AgendaFragment.class, null);

        showFragWeek();
    }

private void showFragWeek(){
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    ft.replace(R.id.realtabcontent, FragWeek);
    ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
    ft.commit();
}

private void showFragMonth(){
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    ft.replace(R.id.realtabcontent, FragMonth);
    ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
    ft.commit();
}

private void showFragDay(){
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    ft.replace(R.id.realtabcontent, FragDay);
    ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
    ft.commit();
}

private void showFragAgenda(){
     FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
     ft.replace(R.id.realtabcontent, FragAgenda);
     ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
     ft.commit();
}

}

这是我运行 logcat 时显示的内容

03-01 10:07:28.655: E/AndroidRuntime(6814): FATAL EXCEPTION: main
03-01 10:07:28.655: E/AndroidRuntime(6814): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bmooredev.bpassistant/com.bmooredev.bpassistant.EventsActivity}: android.view.InflateException: Binary XML file line #1: Error inflating class android.support.v4.app.FragmentTabHost
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.os.Handler.dispatchMessage(Handler.java:99)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.os.Looper.loop(Looper.java:137)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.ActivityThread.main(ActivityThread.java:4745)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at java.lang.reflect.Method.invokeNative(Native Method)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at java.lang.reflect.Method.invoke(Method.java:511)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at dalvik.system.NativeStart.main(Native Method)
03-01 10:07:28.655: E/AndroidRuntime(6814): Caused by: android.view.InflateException: Binary XML file line #1: Error inflating class android.support.v4.app.FragmentTabHost
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:698)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.view.LayoutInflater.inflate(LayoutInflater.java:466)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.Activity.setContentView(Activity.java:1867)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at com.bmooredev.bpassistant.EventsActivity.onCreate(EventsActivity.java:26)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.Activity.performCreate(Activity.java:5008)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
03-01 10:07:28.655: E/AndroidRuntime(6814):     ... 11 more
03-01 10:07:28.655: E/AndroidRuntime(6814): Caused by: java.lang.ClassNotFoundException: android.support.v4.app.FragmentTabHost
03-01 10:07:28.655: E/AndroidRuntime(6814):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.view.LayoutInflater.createView(LayoutInflater.java:552)
03-01 10:07:28.655: E/AndroidRuntime(6814):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:687)
03-01 10:07:28.655: E/AndroidRuntime(6814):     ... 20 more

此外，如果我使用 2.2 构建项目，该项目使用完全相同的代码运行良好。