Question

编辑2：片段适配器：

public class PageAdapter extends FragmentStatePagerAdapter {
    ArrayList<Song> songList; //Update
    public PageAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int i) {
        switch (i) {
            case 0:
                return MusicList.newInstance(songList); //Update
        }
        return null;
    }

    @Override
    public int getCount() {
        return 1; //No of Tabs
    }
}

编辑： id.music_list_fragment（layout.fragment_main）布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/music_list_fragment"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="@drawable/headphones">

    <ListView
        android:id="@+id/song_list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:clickable="true">
    </ListView>

</LinearLayout>

我正在尝试通过替换片段将活动“MainActivity”中的数组列表发送到其片段“MusicList”。

在活动中使用它：

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    Fragment fragment = MusicList.newInstance(songList);
    ft.replace(R.id.music_list_fragment, fragment);
    ft.commit();

在片段中使用它：

public static MusicList newInstance(ArrayList<Song> songList) {
    MusicList fragment = new MusicList();
    Bundle bundle = new Bundle();
    bundle.putSerializable(DESCRIBABLE_KEY, songList);
    fragment.setArguments(bundle);

    return fragment;
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.fragment_main, container, false);
    mList = ((ListView)v.findViewById(R.id.song_list));
    msongList = (ArrayList<Song>) getArguments().getSerializable(DESCRIBABLE_KEY);
    SongAdapter sAdapter = new SongAdapter(getActivity(), msongList);
    mList.setAdapter(sAdapter);

    return v;
}

我收到了这个错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{pal.mplayercomeon/pal.mplayercomeon.MainActivity}: java.lang.IllegalArgumentException: No view found for id 0x7f0c0074 (pal.mplayercomeon:id/music_list_fragment) for fragment MusicList{ee972d3 #0 id=0x7f0c0074}
                                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
                                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
                                                                       at android.app.ActivityThread.-wrap12(ActivityThread.java)
                                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
                                                                       at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                       at android.os.Looper.loop(Looper.java:154)
                                                                       at android.app.ActivityThread.main(ActivityThread.java:6077)
                                                                       at java.lang.reflect.Method.invoke(Native Method)
                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                                                                    Caused by: java.lang.IllegalArgumentException: No view found for id 0x7f0c0074 (pal.mplayercomeon:id/music_list_fragment) for fragment MusicList{ee972d3 #0 id=0x7f0c0074}
                                                                       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1059)
                                                                       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1252)
                                                                       at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:742)
                                                                       at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617)
                                                                       at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:339)
                                                                       at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:601)
                                                                       at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1248)
                                                                       at android.app.Activity.performStart(Activity.java:6681)
                                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2609)
                                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
                                                                       at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
                                                                       at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                       at android.os.Looper.loop(Looper.java:154) 
                                                                       at android.app.ActivityThread.main(ActivityThread.java:6077) 
                                                                       at java.lang.reflect.Method.invoke(Native Method) 
                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

Answer 1

在传递给Fragment newInstance方法之前，需要初始化ArrayList，否则为null。
您正在使用PagerAdapter，因此您将其添加到ViewPager。您不需要FragmentTransaction，因此代码无关紧要。适配器的getCount方法加载ViewPager中的许多片段。
对2的跟进，这是不正确的...... ft.replace(R.id.music_list_fragment, fragment);，除非{strong 1}}作为 FrameLayout 包含在活动中 XML，而不是Fragment XML。但是，如上所述，您似乎想要使用ViewPager

附加点 - Song需要实现android:id="@+id/music_list_fragment"，但是，您确实应该使用Serializable，因为这是在Android中传递数据的首选方式。

Answer 2

您尝试通过从活动中调用片段的linearlayout视图ID来从活动中替换片段内的视图。您需要将<FrameLayout>添加到您的活动xml

<FrameLayout android:id="@+id/fragment_placeholder" 
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

这将保留你的片段，直到你打电话：

ft.replace(R.id.fragment_placeholder, fragment);

设置属于主活动片段的数组

2 个答案: