android - Xamarin Android - 在 fragment 中使用 FragmentTabHost

Question

我正在制作一个抽屉导航应用程序，它使用 Fragments。我正在尝试创建一个 Fragment，它使用带有 FragmentTabHost 的选项卡。我遇到的问题是我在选项卡中期望的内容不存在。这只是一个空白标签。

Fragment 是 Android.Support.V4.App.Fragment。

这是我的代码:

class MyTabFragment : Fragment
{
    private FragmentTabHost mTabHost;

    public override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

    }

    public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        mTabHost = new FragmentTabHost(Activity);
        mTabHost.Setup(Activity, ChildFragmentManager);
        mTabHost.AddTab(mTabHost.NewTabSpec("ATab").SetIndicator("ATab"), 
            Java.Lang.Class.FromType(typeof(MyCustomFragment)), null);
        return mTabHost;
    }

    public override void OnDestroyView()
    {
        base.OnDestroyView();
        mTabHost = null;
    }
}

或者我试过这个:

    public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        return inflater.Inflate(Resource.Layout.fragment_tabhost, container, false);
    }

    public override void OnStart()
    {
        base.OnStart();
        mTabHost = View.FindViewById<FragmentTabHost>(Resource.Id.tabhost);
        mTabHost.Setup(Activity, ChildFragmentManager, Resource.Id.realtabcontent);
        mTabHost.AddTab(mTabHost.NewTabSpec("ATab").SetIndicator("ATab"), 
            Java.Lang.Class.FromType(typeof(MyCustomFragment)), null);
    }

xml:

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

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

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

        <FrameLayout
            android:id="@+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>

但在那种情况下，我会抛出一个致命异常。这是堆栈跟踪:

 FATAL EXCEPTION: main
 java.lang.IllegalStateException: No tab known for tag null
    at android.support.v4.app.FragmentTabHost.doTabChanged(FragmentTabHost.java:330)
    at android.support.v4.app.FragmentTabHost.onAttachedToWindow(FragmentTabHost.java:280)
    at android.view.View.dispatchAttachedToWindow(View.java:11937)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2415)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2422)
    at android.view.ViewGroup.addViewInner(ViewGroup.java:3378)
    at android.view.ViewGroup.addView(ViewGroup.java:3210)
    at android.view.ViewGroup.addView(ViewGroup.java:3155)
    at android.view.ViewGroup.addView(ViewGroup.java:3131)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:953)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1121)
    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1484)
    at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:450)
    at android.os.Handler.handleCallback(Handler.java:725)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:5041)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
    at dalvik.system.NativeStart.main(Native Method)

Answer 1

我想通了。

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
    View rootView = inflater.Inflate(Resource.Layout.fragment_tabhost, container, false);
    mTabHost = rootView.FindViewById<FragmentTabHost>(Resource.Id.tabhost);
    mTabHost.Setup(Activity, ChildFragmentManager, Resource.Id.realtabcontent);
    mTabHost.AddTab(mTabHost.NewTabSpec("ATab").SetIndicator("ATab"),
            Java.Lang.Class.FromType(typeof(MyCustomFragment)), null);
    return rootView;
}