活動不能被轉換到android.support.v4.app.Fragment

Question

我想改變我的應用，該應用有一堆單個活動的成刷卡標籤的應用程序。 我想要在滑動選項卡中的3個活動。我使用了爲我創建的google eclipse例子。我似乎沒有得到正確的做法。

我有以下的（相關）代碼（其他的東西是Eclipse，這太過分了，張貼在這裏）：

Main.class被稱爲在發射（最後一個內部類的話）：

public static class DummySectionFragment extends Fragment { 


public static final String ARG_SECTION_NUMBER = "section_number"; 

     // public DummySectionFragment() { 
     // } 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
       Bundle savedInstanceState) { 

      View rootView = inflater.inflate(R.layout.activity_fragment, 
        container, false); 

      return rootView; 
     } 
    } 

activity_fragment.xml：

<fragment 
    android:id="@+id/main" 
    android:name="com.mikebdev.refuel.MainActivity" 
    class="com.mikebdev.refuel.MainActivity" 
    android:layout_width="0dp" 
    android:layout_height="match_parent" 
    android:layout_weight="1" /> 

<fragment 
    android:id="@+id/stats" 
    android:name="com.mikebdev.refuel.Statistics" 
    android:layout_width="0dp" 
    android:layout_height="match_parent" 
    android:layout_weight="2" /> 

<fragment 
    android:id="@+id/refuel" 
    android:name="com.mikebdev.refuel.ReFuel" 
    android:layout_width="0dp" 
    android:layout_height="match_parent" 
    android:layout_weight="3" /> 

活動的所有從android.support.v4.app.FragmentActivity

延長

從現在開始我的應用程序時，我得到以下錯誤：

嵌入到XML佈局文件

04-27 12:08:11.244: E/AndroidRuntime(28728): FATAL EXCEPTION: main 
04-27 12:08:11.244: E/AndroidRuntime(28728): android.view.InflateException: Binary XML file line #8: Error inflating class fragment 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.LayoutInflater.rInflate(LayoutInflater.java:746) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.LayoutInflater.inflate(LayoutInflater.java:489) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.LayoutInflater.inflate(LayoutInflater.java:396) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at com.mikebdev.refuel.Main$DummySectionFragment.onCreateView(Main.java:184) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1460) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:911) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:461) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:163) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.view.ViewPager.populate(ViewPager.java:1011) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.view.ViewPager.populate(ViewPager.java:880) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1374) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.View.measure(View.java:15518) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.View.measure(View.java:15518) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.widget.LinearLayout.measureVertical(LinearLayout.java:847) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.widget.LinearLayout.onMeasure(LinearLayout.java:588) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.View.measure(View.java:15518) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2176) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.View.measure(View.java:15518) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1874) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1089) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1265) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.Choreographer.doCallbacks(Choreographer.java:562) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.Choreographer.doFrame(Choreographer.java:532) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.os.Handler.handleCallback(Handler.java:725) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.os.Handler.dispatchMessage(Handler.java:92) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.os.Looper.loop(Looper.java:137) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.app.ActivityThread.main(ActivityThread.java:5041) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at java.lang.reflect.Method.invokeNative(Native Method) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at java.lang.reflect.Method.invoke(Method.java:511) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at dalvik.system.NativeStart.main(Native Method) 
04-27 12:08:11.244: E/AndroidRuntime(28728): Caused by: java.lang.ClassCastException: com.mikebdev.refuel.MainActivity cannot be cast to android.support.v4.app.Fragment 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.Fragment.instantiate(Fragment.java:394) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.Fragment.instantiate(Fragment.java:369) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:272) 
04-27 12:08:11.244: E/AndroidRuntime(28728): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:676) 

Answer 1

過了一會兒，我能夠在這裏增加一個開關case語句來解決所有問題：

@Override 
     public Fragment getItem(int position) { 
      // getItem is called to instantiate the fragment for the given page. 
      // Return a DummySectionFragment (defined as a static inner class 
      // below) with the page number as its lone argument. 

      Fragment fragment; 
      switch (position) { 
       case 0: 
        fragment = new StatisticsFragment(); 
        break; 
       case 1: 
        fragment = new MainActivityFragment(); 
        break; 
       case 2: 
        fragment = new DbListViewFragment(); 
        break; 
       default: 
        fragment = new DummySectionFragment(); 
        break; 
      } 
      return fragment; 
     } 

和我做了我的副本活動，並轉換那些在這個視頻解釋樣片段：

Converting An Activity To A Fragment

現在一切似乎工作。

Answer 2

不能嵌套片段。你必須在運行時添加它們。

編輯：有上實現滑動式標籤與片段，請看看他們無數的教程，很多是自我解釋。的要點是：

• 創建其中將包含接頭和ViewPager
• 創建將被用作標籤中的片段的佈局文件/在ViewPager
• 頁面創建FragmentPagerAdapter併爲它分配到ViewPager
• 綁定選項卡選擇到ViewPager頁面。

您可以使用ViewPager直接在Activity或者你可以使用一個包裝Fragment，所不同的是，你需要通過getChildFragmentManager()到FragmentPagerAdapter而不是getSupportFragmentManager()。