Question

在Fragments的帮助下开发Gems应用程序时，运行时发生了logcat错误。

logcat的：

 E/AndroidRuntime(667): FATAL EXCEPTION: main
 E/AndroidRuntime(667): java.lang.NullPointerException
 E/AndroidRuntime(667): at com.sit.gems.frgment.HomeBaseFragment.onMoreFragmentOptionSelected(HomeBaseFragment.java:345)
 E/AndroidRuntime(667): at com.sit.gems.activity.HomeActivity.onMoreFragmentOptionSelected(HomeActivity.java:80)
 E/AndroidRuntime(667): at com.sit.gems.frgment.MoreFragment$1.onItemClick(MoreFragment.java:44)
 E/AndroidRuntime(667): at android.widget.AdapterView.performItemClick(AdapterView.java:292)
 E/AndroidRuntime(667): at android.widget.AbsListView.performItemClick(AbsListView.java:1058)
 E/AndroidRuntime(667): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2514)
 E/AndroidRuntime(667): at android.widget.AbsListView$1.run(AbsListView.java:3168)
 E/AndroidRuntime(667): at android.os.Handler.handleCallback(Handler.java:605)
 E/AndroidRuntime(667): at android.os.Handler.dispatchMessage(Handler.java:92)
 E/AndroidRuntime(667): at android.os.Looper.loop(Looper.java:137)
 E/AndroidRuntime(667): at android.app.ActivityThread.main(ActivityThread.java:4340)
 E/AndroidRuntime(667): at java.lang.reflect.Method.invokeNative(Native Method)
 E/AndroidRuntime(667): at java.lang.reflect.Method.invoke(Method.java:511)
 E/AndroidRuntime(667): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
 E/AndroidRuntime(667): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
 E/AndroidRuntime(667): at dalvik.system.NativeStart.main(Native Method)

HomeBaseFragment.java：

package com.sit.gems.frgment;

public class HomeBaseFragment extends BaseFragment implements OnTabChangeListener {

    private View mRoot;
    private TabHost mTabHost;
    private int mCurrentTab;
    private AudioFragment mAudioFragment;
    private LiveStreamFragment liveStreamFragment;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        new GetLiveStreamVideoTask(getActivity()).execute();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        mRoot = inflater.inflate(R.layout.layout_home, null);
        mTabHost = (TabHost) mRoot.findViewById(android.R.id.tabhost);

        mAudioFragment = new AudioFragment();
        liveStreamFragment = new LiveStreamFragment();
        setupTabs();



        return mRoot;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        updateTab("Home", R.id.tab_home);
    }

    public class GetLiveStreamVideoTask extends CustomAsyncTask {

        private String responseString;

        public GetLiveStreamVideoTask(Activity activity) {
            super(activity);
            enableLoadingDialog(false);
        }

        @Override
        public void doTask() throws Exception {

            responseString = APIServiceHandler
                    .getData("http://splendor.pro/gemapp/api/livestream.php");

        }

        @Override
        public void doFinish() {

            if (responseString != null) {

                try {
                    JSONObject resposeJsonObject = new JSONObject(
                            responseString);
                    int statusCode = resposeJsonObject.optInt("statusCode", 0);
                    if (statusCode == 200) {
                        JSONArray jsonArray = resposeJsonObject
                                .getJSONArray("videos");
                        List<Video> videos = new ArrayList<Video>();
                        for (int i = 0; i < jsonArray.length(); i++) {
                            Video video = new Video(jsonArray.getJSONObject(i));
                            videos.add(video);
                        }
                        if(videos.size()>0){
                            Video video=videos.get(0);
                            appData.setLiveStreamVideo(video);
                        }


                    } 
                } catch (Exception e) {
                }

            }

        }

    }

    private void setupTabs() {
        mTabHost.setup();
        mTabHost.addTab(newTab(getString(R.string.str_home), R.string.str_home,
                R.drawable.home_selector, R.id.tab_home));
        mTabHost.addTab(newTab(getString(R.string.str_video),
                R.string.str_video, R.drawable.video_icon_selector,
                R.id.tab_video));
        mTabHost.addTab(newTab(getString(R.string.str_audio),
                R.string.str_audio, R.drawable.audio_icon_selector,
                R.id.tab_audio));
        mTabHost.addTab(newTab(getString(R.string.str_blog), R.string.str_blog,
                R.drawable.blog_icon_selector, R.id.tab_blog));
        mTabHost.addTab(newTab(getString(R.string.str_gal), R.string.str_gal,
                R.drawable.gal_icon_selector, R.id.tab_gal));
        mTabHost.addTab(newTab(getString(R.string.str_more), R.string.str_more,
                R.drawable.more_icon_selector, R.id.tab_more));

        mTabHost.setOnTabChangedListener(this);

    }

    private TabSpec newTab(String tag, int labelId, int tabImg, int tabContentId) {

        View indicator = LayoutInflater.from(getActivity()).inflate(
                R.layout.tab,
                (ViewGroup) mRoot.findViewById(android.R.id.tabs), false);
        TextView textView = ((TextView) indicator.findViewById(R.id.tab_text));
        textView.setText(labelId);
        textView.setTypeface(AppData.getTitleFont());
        ((ImageView) indicator.findViewById(R.id.tab_img))
                .setImageResource(tabImg);

        TabSpec tabSpec = mTabHost.newTabSpec(tag);
        tabSpec.setIndicator(indicator);
        tabSpec.setContent(tabContentId);
        return tabSpec;
    }

    @Override
    public void onTabChanged(String arg0) {
        if (getString(R.string.str_home).equals(arg0)) {
            updateTab(arg0, R.id.tab_home);
            mCurrentTab = 0;
            return;
        } else if (getString(R.string.str_video).equals(arg0)) {
            updateTab(arg0, R.id.tab_video);
            mCurrentTab = 1;
            return;
        } else if (getString(R.string.str_audio).equals(arg0)) {
            updateTab(arg0, R.id.tab_audio);
            mCurrentTab = 2;
            return;
        } else if (getString(R.string.str_blog).equals(arg0)) {
            updateTab(arg0, R.id.tab_blog);
            mCurrentTab = 3;
            return;
        } else if (getString(R.string.str_gal).equals(arg0)) {
            updateTab(arg0, R.id.tab_gal);
            mCurrentTab = 4;
            return;
        } else if (getString(R.string.str_more).equals(arg0)) {

            updateTab(arg0, R.id.tab_more);
            mCurrentTab = mTabHost.getCurrentTab();
            return;
        }

    }

    private void updateTab(String tabId, int placeholder) {

        FragmentManager fm = getFragmentManager();

        mAudioFragment.stopPlay(tabId);


        if (fm.findFragmentByTag(tabId) == null) {
            if(AppData.isVideoPlaying && fm.findFragmentById(R.id.tab_video) != null){
                fm.popBackStack();
            }
            switch (placeholder) {
            case R.id.tab_home:
                fm.beginTransaction()
                        .replace(placeholder, new HomeFragment(), tabId)
                        .commit();
                break;
            case R.id.tab_video:
                fm.beginTransaction()
                        .replace(placeholder, new VideoFragment(), tabId)
                        .commit();
                break;
            case R.id.tab_audio:
                fm.beginTransaction()
                        .replace(placeholder, mAudioFragment, tabId).commit();
                break;
            case R.id.tab_blog:
                fm.beginTransaction()
                        .replace(placeholder, new BlogFragment(), tabId)
                        .commit();
                break;
            case R.id.tab_gal:
                fm.beginTransaction()
                        .replace(placeholder, new GalleryFragment(), tabId)
                        .commit();
                break;
            case R.id.tab_more:
                fm.beginTransaction()
                        .replace(placeholder, new MoreFragment(), tabId)
                        .commit();
                break;
            default:
                fm.beginTransaction()
                        .replace(placeholder, new HomeFragment(), tabId)
                        .commit();
                break;
            }

        } else if (fm.findFragmentByTag(tabId) != null) {
            if (tabId.equalsIgnoreCase(getString(R.string.str_more))) {
                fm.popBackStack();
            }

            if(AppData.isVideoPlaying && fm.findFragmentById(R.id.tab_video) != null){
                fm.popBackStack();
            }

        }
    }

    public void OnAudioSelected(Audio audio) {
        LiveStreamFragment audioDetailFragment = new LiveStreamFragment();
        FragmentTransaction transaction = getActivity()
                .getSupportFragmentManager().beginTransaction();
        transaction.replace(R.id.tab_audio, audioDetailFragment);
        transaction.addToBackStack(null);
        transaction.commit();
    }

    public void OnBlogSelected(Blog blog,String lang) {

        BlogDetailFragment blogDetailFragment = new BlogDetailFragment();
        Bundle bundle = new Bundle();
        bundle.putParcelable("blog", blog);
        bundle.putString("lang", lang);
        blogDetailFragment.setArguments(bundle);
        FragmentTransaction transaction = getActivity()
                .getSupportFragmentManager().beginTransaction();
        transaction.replace(R.id.tab_blog, blogDetailFragment);
        transaction.addToBackStack(null);
        transaction.commit();

    }

    public void OnVideoSelected(Video video) {


        FragmentTransaction transaction = getActivity()
                .getSupportFragmentManager().beginTransaction();
        if(video.getVideoType().equalsIgnoreCase("Youtube")){
            Intent intent=new Intent(getActivity(),YoutubePlayActivity.class);
            intent.putExtra("videoid", video.getVideoUrl());
            intent.putExtra("title", video.getVideoTitle());
            startActivity(intent);
        }else{
            LiveStreamFragment tubePlayFragment=new LiveStreamFragment();

            Bundle bundle=new Bundle();
            bundle.putString("live","VIDEO");
            if(AppData.isAudioAvalableinSD(video.getVideoTitle().trim())){
                try {
                    bundle.putString("url", AppData.getPath(video.getVideoTitle().trim()));
                } catch (Exception e) {
                    bundle.putString("url", video.getVideoUrl());
                }
            }else{
                bundle.putString("url", video.getVideoUrl());
            }
            tubePlayFragment.setArguments(bundle);
            transaction.replace(R.id.tab_video, tubePlayFragment);

        }
        transaction.addToBackStack(null);
        transaction.commit();
    }

    public void onMoreFragmentOptionSelected(final int option) {
        switch (option) {
        case 1:
            AnnouncenentFragment fragment = new AnnouncenentFragment();
            FragmentTransaction transaction = getActivity()
                    .getSupportFragmentManager().beginTransaction();
            transaction.replace(R.id.tab_more, fragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;
        case 2:
            MagzineFragment magzineFragment = new MagzineFragment();
            transaction = getActivity().getSupportFragmentManager()
                    .beginTransaction();
            transaction.replace(R.id.tab_more, magzineFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;
        case 3:
            CategoryFragment categoryFragment = new CategoryFragment();
            transaction = getActivity().getSupportFragmentManager()
                    .beginTransaction();
            transaction.replace(R.id.tab_more, categoryFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;
        case 4:
            LiveStreamFragment liveStreamFragment=new LiveStreamFragment();
            transaction = getActivity().getSupportFragmentManager()
                    .beginTransaction();
            Bundle bundle=new Bundle();
            bundle.putString("live","LIVE STREAMING");
            bundle.putString("url", appData.getLiveStreamVideo().getVideoUrl());  //345th Line
            liveStreamFragment.setArguments(bundle);
            transaction.replace(R.id.tab_more, liveStreamFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;
        case 5:
            PrayerRequestFragment prayerRequest = new PrayerRequestFragment();
            transaction = getActivity().getSupportFragmentManager()
                    .beginTransaction();
            transaction.replace(R.id.tab_more, prayerRequest);
            transaction.addToBackStack(null);
            transaction.commit();
            break;  
        case 6:
            SettingsFragment settingsFragment = new SettingsFragment();
            transaction = getActivity().getSupportFragmentManager()
                    .beginTransaction();
            transaction.replace(R.id.tab_more, settingsFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;      


        default:
            break;
        }

    }

}

AppData.java：

package com.sit.gems.app;


public class AppData {

    private static Context mContext;
    private static Typeface typefaceTamil;
    private static Typeface typefaceEnglish;
    private static Typeface typefaceHindi;
    private static Typeface typefaceTitle;
    private List<Gallery> galleries;
    private List<String> languages;
    private String language;
    private Map<String, List<Blog>> mapBlog;
    private Map<String, List<Audio>> mapAudio;
    private Map<String, List<Video>> mapVideo;
    private List<Announcement> announcements;
    private Map<String,List<Product>> products;
    private List<Category> categories;
    private boolean isPlaying;
    private static int screenWidth;
    public static boolean isVideoPlaying=false;
    private int screenHeight;
    private String magzfiles;
    private List<Magzine> magzines;
    private Video liveStreamVideo;
    private String blogLang;
    private String videoLang;

    public AppData(Context context) {
        mContext = context;
        languages = new ArrayList<String>();
        addLanguages();
        WindowManager windowManager = (WindowManager) mContext
                .getSystemService(Context.WINDOW_SERVICE);
        Display display = windowManager.getDefaultDisplay();
        screenWidth = display.getWidth();
        screenHeight = display.getHeight();
        mapAudio = new HashMap<String, List<Audio>>();
        mapBlog = new HashMap<String, List<Blog>>();
        mapVideo = new HashMap<String, List<Video>>();
        this.products=new HashMap<String, List<Product>>();
    }

    private void addLanguages() {
        languages.add("English");
        languages.add("Tamil");
        languages.add("Hindi");

    }

    private static void initFontStyles() {
        typefaceTamil = Typeface.createFromAsset(mContext.getAssets(),
                "fonts/tamil_nambi.ttf");

        typefaceEnglish = Typeface.DEFAULT;
        typefaceHindi = Typeface.createFromAsset(mContext.getAssets(),
                "fonts/vigyapti.ttf");

        typefaceTitle=Typeface.DEFAULT_BOLD;
    }

    public static Typeface getTamilFont() {
        if (typefaceTamil == null) {
            initFontStyles();
        }
        return typefaceTamil;
    }

    public static Typeface getTitleFont() {
        if (typefaceTitle == null) {
            initFontStyles();
        }
        return typefaceTitle;
    }

    public static Typeface getEnglishFont() {
        if (typefaceEnglish == null) {
            initFontStyles();
        }
        return typefaceEnglish;
    }

    public static Typeface getHindiFont() {
        if (typefaceHindi == null) {
            initFontStyles();
        }
        return typefaceHindi;
    }

    public List<String> getlanguages() {
        return languages;
    }

    public void setBlogs(String lnag, List<Blog> blogs) {
        if (mapBlog == null) {
            mapBlog = new HashMap<String, List<Blog>>();
        }
        mapBlog.put(lnag, blogs);
    }

    public List<Gallery> getGalleries() {
        return galleries;
    }

    public void setGalleries(List<Gallery> galleries) {
        this.galleries = galleries;
    }

    public String getLanguage() {
        return language;
    }

    public void setLanguage(String language) {
        this.language = language;
    }

    public List<Blog> getBlogs(String lang) {
        return mapBlog.get(lang);
    }

    public List<Audio> getAudios(String lang) {

        return mapAudio.get(lang);
    }

    public void setAudios(String lang, List<Audio> audios) {
        if (mapAudio == null) {
            mapAudio = new HashMap<String, List<Audio>>();
        }
        mapAudio.put(lang, audios);
    }

    public void setVideos(String lang, List<Video> videos) {
        if (mapVideo == null) {
            mapVideo = new HashMap<String, List<Video>>();
        }
        mapVideo.put(lang, videos);
    }

    public List<Video> getVideos(String lang) {

        return mapVideo.get(lang);
    }

    public static Typeface getTypeFace(String language) {
        if (language.equalsIgnoreCase("English")) {
            return getEnglishFont();
        } else if (language.equalsIgnoreCase("Hindi")) {
            return getHindiFont();
        } else if (language.equalsIgnoreCase("Tamil")) {
            return getTamilFont();
        }

        return getEnglishFont();
    }

    public void clearData() {
        if (mapAudio != null)
            mapAudio.clear();
        if (mapBlog != null)
            mapBlog.clear();
        if (mapVideo != null)
            mapVideo.clear();
        if(galleries!=null)
            galleries.clear();
        if(announcements!=null)
            announcements.clear();
        if(products!=null)
            products.clear();
        if(magzines!=null)
            magzines.clear();

        setBlogLang(null);
        setVideoLang(null);


    }

    public boolean isPlaying() {
        return isPlaying;
    }

    public void setPlaying(boolean isPlaying) {
        this.isPlaying = isPlaying;
    }

    public List<Announcement> getAnnouncements() {
        return announcements;
    }

    public void setAnnouncements(List<Announcement> announcements) {
        this.announcements = announcements;
    }

    public List<Product> getProducts(String cat) {
        return products.get(cat);
    }

    public void setProducts(String cat,List<Product> products) {
        if(this.products==null)
            this.products=new HashMap<String, List<Product>>();
        this.products.put(cat, products);
    }

    public List<Category> getCategories() {
        return categories;
    }

    public void setCategories(List<Category> categories) {
        this.categories = categories;
    }

    public static int getScreenWidth() {
        return screenWidth;
    }

    public List<Magzine> getMagzines() {
        return magzines;
    }

    public void setMagzines(List<Magzine> magzines) {
        this.magzines = magzines;
    }

    public void setLiveStreamVideo(Video video) {
        liveStreamVideo=video;

    }
    public Video getLiveStreamVideo() {
        return liveStreamVideo;

    }

    public void setBlogLang(String lang) {
        blogLang=lang;
    }
    public String getBlogLang() {
        return blogLang;
    }

    public static boolean isAudioAvalableinSD(String title) {
        String path ="";
        try {
            path = getPath(title);
            if(path==null)
                return false;   
        } catch (Exception e) {
            return false;
        }

        try {
            File f = new File(path);
            if (!f.exists()) {
                return false;
            }

        } catch (Exception e) {
            return false;
        }
        return true;
    }

    public static String getPath(String title)  throws Exception{

        final String cachePath =
                Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()) ||
                        !isExternalStorageRemovable() ? getExternalCacheDir(mContext).getPath() :
                                mContext.getCacheDir().getPath();

        return cachePath+ File.separator +title.trim() + ".mp3";
    }
     public static File getExternalCacheDir(Context context) {
            if (Utils.hasFroyo()) {
                return context.getExternalCacheDir();
            }


            final String cacheDir = "/Android/data/" + context.getPackageName() + "/cache/";
            return new File(Environment.getExternalStorageDirectory().getPath() + cacheDir);
        }
    public static boolean isExternalStorageRemovable() {
        if (Utils.hasGingerbread()) {
            return Environment.isExternalStorageRemovable();
        }
        return true;
    }

    public String getVideoLang() {
        return videoLang;
    }

    public void setVideoLang(String videoLang) {
        this.videoLang = videoLang;
    }
}

BaseFragment.java：

package com.sit.gems.app;

public class BaseFragment extends Fragment {

    private Activity activity;
    protected AppData appData;

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        this.activity = activity;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        appData = ((GemsApplication) activity.getApplication()).getAppData();

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        return super.onCreateView(inflater, container, savedInstanceState);
    }

}

HomeActivity.java：

package com.sit.gems.activity;

public class HomeActivity extends BaseActivity implements
        VideoFragment.OnVideoSelectedListener,
        AudioFragment.OnAudioSelectedListener,
        BlogFragment.OnBlogSelectedListener,
        MoreFragment.OnMoreFragmentOptionSelectedListener,
        AnnouncenentFragment.OnAnnouncementSelectedListener,
        ProductFragment.OnProductSelectedListener,
        GalleryFragment.OnGalItemSelectedListener,
        ProductDetailFragment.OnInquiryListener,
        CategoryFragment.OnCategorySelectedListener,
        MagzineFragment.OnMagzineSelectedListener{

    private HomeBaseFragment fragment;

    @Override
    protected void onCreate(Bundle arg0) {
        super.onCreate(arg0);

        setContentView(R.layout.base_fragment);
        AppPreferences.setAppPreferences(getApplicationContext());
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

        fragment = new HomeBaseFragment();
        getSupportFragmentManager().beginTransaction()
                .add(R.id.fragment_container, fragment).commit();
    }

    @Override
    public void OnAudioSelected(Audio audio) {
        fragment.OnAudioSelected(audio);

    }

    @Override
    public void OnBlogSelected(Blog blog,String lang) {
        fragment.OnBlogSelected(blog,lang);

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        appData.clearData();
    }

    @Override
    public void OnVideoSelected(Video video) {
        fragment.OnVideoSelected(video);

    }

    @Override
    public void onMoreFragmentOptionSelected(int option) {
        fragment.onMoreFragmentOptionSelected(option);  //80th Line
    }

    @Override
    public void OnAnnouncementSelected(Announcement announcement) {
        fragment.onAnnouncementSelected(announcement);

    }

    @Override
    public void OnProductSelected(Product product) {
        fragment.onProductSelected(product);

    }

    @Override
    public void OnGalItemSelected(String pos,String name) {
        fragment.onGalItemSelected(pos,name);

    }

    @Override
    public void OnInquirytSelected(Product product) {
        fragment.onInquirytSelected(product);

    }

    @Override
    public void OncategorySelected(String id,String name) {
        fragment.oncategorySelected(id,name);

    }

    @Override
    public void OnMagzineSelected(Magzine magzine) {

        fragment.onMagzineSelected(magzine);
    }


}

BaseActivity.java：

package com.sit.gems.app;

public class BaseActivity extends FragmentActivity {

    protected AppData appData;

    @Override
    protected void onCreate(Bundle arg0) {
        super.onCreate(arg0);
        appData=((GemsApplication) getApplication()).getAppData();

    }

    public void onDestroyView() {

    }

}

MoreFragment.java：

package com.sit.gems.frgment;

public class MoreFragment extends BaseFragment {

    OnMoreFragmentOptionSelectedListener mCallBack;

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

        View view = inflater.inflate(R.layout.quickaction, null);

        List<String> options=new ArrayList<String>();
        options.add("Announcements");
        options.add("Magazines");
        options.add("Products");
        options.add("Live Streaming");
        options.add("Prayer Request");
        options.add("Settings");

        ListView listView =(ListView) view.findViewById(R.id.tracks);

        listView.setAdapter(new MoreAdapter(getActivity(), 0, options));
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                    long arg3) {
                mCallBack.onMoreFragmentOptionSelected(arg2+1); //44th Line

            }
        });

        return view;
    }


    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        try {
            mCallBack = (OnMoreFragmentOptionSelectedListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement OnHeadlineSelectedListener");
        }
    }

 public interface OnMoreFragmentOptionSelectedListener{
     public void onMoreFragmentOptionSelected(int option);

 }  

}

输出：

enter image description here

如果单击实时流媒体选项，则会出现Log Cat错误发生。
如果有人知道如何解决这些类型的错误。你的回答将是非常欢迎。谢谢！

Answer 1

检查appData对象并确保其已初始化。这似乎是null或返回null网址字符串。

Answer 2

查看导致问题的代码行，看起来你没有在任何地方初始化appData实例，这可能是为什么？

如果这不是问题，您可以通过替换此问题来缩小问题范围或暂时修补问题：

bundle.putString("url", appData.getLiveStreamVideo().getVideoUrl());

有了这个：

try {
    Log.d("LiveStreamVideo", "Screen Width: " + appData.getScreenWidth());
    Log.d("LiveStreamVideo", "Video URL: " + getLiveStreamVideo().getVideoUrl());
    bundle.putString("url", appData.getLiveStreamVideo().getVideoUrl());
} catch (Exception e) {
    e.printStackTrace();
}

如果在期望看到第一个Log输出之前输出堆栈跟踪，则知道appData为null。如果它在第二个日志请求中失败，那么getVideoUrl（）就是问题。

可能是getVideoUrl（）返回null，因为我无法确定它是否存在。也许为这个变量设置一个默认值是为了确保：

private videoUrl = "";

Gems App - 直播片段

2 个答案: