android - 与 Youtube 播放器支持 fragment 作斗争

Question

我试图在 fragment 中使用 Youtube Player Support Fragment，但应用程序总是崩溃 (NullPointerException)，而且我找不到任何类似的帖子来修复它。

我有 import import android.support.v4.app.Fragment 所以这应该不是问题。

这是我的 fragment 类的样子:

package com.example.activitydetector;
import com.google.android.youtube.player.YouTubeBaseActivity;
import com.google.android.youtube.player.YouTubeInitializationResult;
import com.google.android.youtube.player.YouTubePlayer;
import com.google.android.youtube.player.YouTubePlayer.OnInitializedListener;
import com.google.android.youtube.player.YouTubePlayer.Provider;
import com.google.android.youtube.player.YouTubePlayerFragment;
import com.google.android.youtube.player.YouTubePlayerSupportFragment;
import com.google.android.youtube.player.YouTubePlayerView;
import systemManager.SystemManager;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.Toast;

public class GuidelinesFragment extends YouTubePlayerSupportFragment {

    SystemManager sm;
    YouTubePlayerView youTubeView; 
    String URL_VIDEO = "CaA-k1l0xa4";
    String KEY_DEVELOPER = "AIzaSyBIIs0u0NXhsZguv8nCNvSzUmflTt7K1Ek";

    public GuidelinesFragment() {
        super();
        // TODO Auto-generated constructor stub
    }

    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);


    }

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

        View view = inflater.inflate(R.layout.youtube, container, false);


        YouTubePlayerSupportFragment youTubePlayerSupportFragment = (YouTubePlayerSupportFragment) getFragmentManager().findFragmentById(R.id.youtubeplayerfragment);

        youTubePlayerSupportFragment.initialize(KEY_DEVELOPER, new OnInitializedListener() {

            @Override
            public void onInitializationSuccess(Provider arg0, YouTubePlayer arg1,
                    boolean arg2) {
                // TODO Auto-generated method stub
                arg1.cueVideo(URL_VIDEO);
            }

            @Override
            public void onInitializationFailure(Provider arg0,
                    YouTubeInitializationResult arg1) {
                // TODO Auto-generated method stub

            }
        });

        return view;
    }

}

这是我完全简单的“Youtube”布局:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity" >

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

这是日志显示的错误:

    11-30 16:33:56.419: W/dalvikvm(19375): threadid=1: thread exiting with uncaught exception (group=0x40f14258)
11-30 16:33:56.423: E/AndroidRuntime(19375): FATAL EXCEPTION: main
11-30 16:33:56.423: E/AndroidRuntime(19375): java.lang.NullPointerException
11-30 16:33:56.423: E/AndroidRuntime(19375):    at com.google.android.youtube.player.YouTubePlayerSupportFragment.onStart(Unknown Source)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.support.v4.app.Fragment.performStart(Fragment.java:1484)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:941)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:429)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.os.Handler.handleCallback(Handler.java:605)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.os.Handler.dispatchMessage(Handler.java:92)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.os.Looper.loop(Looper.java:137)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at android.app.ActivityThread.main(ActivityThread.java:4645)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at java.lang.reflect.Method.invokeNative(Native Method)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at java.lang.reflect.Method.invoke(Method.java:511)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
11-30 16:33:56.423: E/AndroidRuntime(19375):    at dalvik.system.NativeStart.main(Native Method)

如有任何帮助或提示，我们将不胜感激。我已经浪费了大约 4 个小时而不走运。

Answer 1

我之前遇到过这个问题，我相信这个问题源于试图膨胀 YouTubePlayerSupportFragment 布局。我通过创建这样的 fragment 解决了我的问题:

public class PlayerYouTubeFrag extends YouTubePlayerSupportFragment {
    private String currentVideoID = "video_id";
    private YouTubePlayer activePlayer;

    public static PlayerYouTubeFrag newInstance(String url) {
        PlayerYouTubeFrag playerYouTubeFrag = new PlayerYouTubeFrag();

        Bundle bundle = new Bundle();
        bundle.putString("url", url);

        playerYouTubeFrag.setArguments(bundle);

        return playerYouTubeFrag;
    }

    private void init() {
        initialize(DeveloperKey.DEVELOPER_KEY, new OnInitializedListener() {

            @Override
            public void onInitializationFailure(Provider arg0, YouTubeInitializationResult arg1) { 
            }

            @Override
            public void onInitializationSuccess(YouTubePlayer.Provider provider, YouTubePlayer player, boolean wasRestored) {
                activePlayer = player;
                activePlayer.setPlayerStyle(YouTubePlayer.PlayerStyle.DEFAULT);
                if (!wasRestored) {
                    activePlayer.loadVideo(getArguments().getString("url"), 0);

                }
            }
        });
    }

    @Override
    public void onYouTubeVideoPaused() {
        activePlayer.pause();
    }
}

然后像这样调用 fragment 的一个实例:

PlayerYouTubeFrag myFragment = PlayerYouTubeFrag.newInstance("video_id");
getSupportFragmentManager().beginTransaction().replace(R.id.video_container, myFragment).commit();

在我的例子中，video_container 是一个空的框架布局。