android - 如何在我的 SupportFragment 中添加 YouTube 播放器？

Question

我的 XML 代码:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    style="@style/Container.MainBackground"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment android:name="com.google.android.youtube.player.YouTubePlayerSupportFragment"
        android:layout_alignParentTop="true"
        android:id="@+id/youtube_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</RelativeLayout>

fragment 中的代码

public class VideoFragment extends YouTubePlayerSupportFragment implements YouTubePlayer.OnInitializedListener {

    static private final String DEVELOPER_KEY = "MyKey";
    static private final String VIDEO = "ToMpzhdUD1Q";
    static private final String VIDEO1 = "K77avo920Jc";
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View videoView = inflater.inflate(R.layout.video_fragment, container, false);
        getActivity().setTitle("Youtube");

        YouTubePlayerSupportFragment youTubePlayerSupportFragment = new YouTubePlayerSupportFragment();
        youTubePlayerSupportFragment.initialize(DEVELOPER_KEY, this);

        return videoView;
    }

    @Override
    public void onInitializationSuccess(YouTubePlayer.Provider provider, YouTubePlayer youTubePlayer, boolean b) {

        List<String> list = new ArrayList<>();
        list.add(VIDEO);
        list.add(VIDEO1);
        youTubePlayer.setPlayerStyle(YouTubePlayer.PlayerStyle.DEFAULT);
        youTubePlayer.cueVideos(list);

    }

    @Override
    public void onInitializationFailure(YouTubePlayer.Provider provider, YouTubeInitializationResult youTubeInitializationResult) {

        Toast.makeText(getContext(), "FAIL!" + youTubeInitializationResult.toString(), Toast.LENGTH_LONG)
                .show();

    }
}

在主要 Activity 中:

getSupportFragmentManager().beginTransaction().replace(R.id.main_container,fragment).addToBackStack(null).commit();

当我尝试在抽屉中打开我的 Fragment 时出错:

java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.youtube.player.YouTubePlayerView.a()' on a null object reference at com.google.android.youtube.player.YouTubePlayerSupportFragment.onStart(Unknown Source)

Answer 1

这里的问题是您覆盖了父类(super class) YouTubePlayerSupportFragment 中的 onCreateView() 方法，该方法不是抽象的，实际上有一个实现，如看到:

    public View onCreateView(LayoutInflater var1, ViewGroup var2, Bundle var3) {
        this.c = new YouTubePlayerView(this.getActivity(), (AttributeSet)null, 0, this.a);
        this.a();
        return this.c;
    }

实际的变量名和类型超出了这个答案的范围。这里重要的是 YouTubePlayerView 在这里被实例化，你覆盖了这个方法，所以 YouTubePlayerView 在 onStart() 中被调用时是 null方法(也可在 YouTubePlayerSupportFragment 中找到)。

    public void onStart() {
        super.onStart();
        this.c.a();
    }

因此，基本上，您唯一需要做的就是实例化您的 VideoFragment 类，如果您想要实际的视频而不是黑框，则需要初始化 fragment ，位于它的创建时间，(像这样:)

    public VideoFragment()
    {
        this.initialize("yourAPIKeyHere", this);
    }