java - 我的 RSS 解析器代码不断崩溃，我找不到问题所在

Question

我正在尝试在列表视图中获取和显示实时新闻，但它崩溃了。

我查看了社区解决的一些教程和问题，但我仍然无法在我的代码中找到问题所在。我在一个片段内工作，我正在使用 MVC 结构。

public class HomeFragment extends Fragment {
    private MutableLiveData<List<Article>> articleListLive = null;
    private String urlString = "https://www.androidauthority.com/feed";
    private RecyclerView mRecyclerView;
    private ArticleAdapter mAdapter;
    private ArrayList<Article> listArticle = new ArrayList<Article>();
    public HomeFragment() {
        // Required empty public constructor
    }
    public static HomeFragment newInstance () {
        return (new HomeFragment());
    }


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

        View rootView = inflater.inflate(R.layout.fragment_home, container, false);

        ListView listView = (ListView)rootView.findViewById(R.id.news_list);
        listView.setAdapter((ListAdapter) new ArticleAdapter(listArticle,getContext()));

        return rootView;
    }

    public void fetchFeed() {

        Parser parser = new Parser();
        parser.onFinish(new OnTaskCompleted() {


            @Override
            public void onTaskCompleted(List<Article> list) {
                setArticleList(list);
            }

            @Override
            public void onError(Exception e) {
                setArticleList(new ArrayList<Article>());
                e.printStackTrace();
                snackbar.postValue("An error has occurred. Please try again");
            }
        });
        parser.execute(urlString);
    }
    private MutableLiveData<String> snackbar = new MutableLiveData<>();

    public MutableLiveData<List<Article>> getArticleList() {
        if (articleListLive == null) {
            articleListLive = new MutableLiveData<>();
        }
        return articleListLive;
    }
    private void setArticleList(List<Article> articleList) {
        this.articleListLive.postValue(articleList);
    }


}

我期待一个新闻列表，但它崩溃了。这是我的适配器类：

public class ArticleAdapter extends RecyclerView.Adapter<ArticleAdapter.ViewHolder> {

    private List<Article> articles;

    private Context mContext;
    private WebView articleView;

    public ArticleAdapter(List<Article> list, Context context) {
        this.articles = list;
        this.mContext = context;
    }

    public List<Article> getArticleList() {
        return articles;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.row, viewGroup, false);
        return new ViewHolder(v);
    }

    @Override
    public void onBindViewHolder(@NonNull final ViewHolder viewHolder, int position) {

        Article currentArticle = articles.get(position);

        String pubDateString;
        try {
            String sourceDateString = currentArticle.getPubDate();

            SimpleDateFormat sourceSdf = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z", Locale.ENGLISH);
            Date date = sourceSdf.parse(sourceDateString);

            SimpleDateFormat sdf = new SimpleDateFormat("dd MMMM yyyy", Locale.getDefault());
            pubDateString = sdf.format(date);

        } catch (ParseException e) {
            e.printStackTrace();
            pubDateString = currentArticle.getPubDate();
        }

        viewHolder.title.setText(currentArticle.getTitle());

        Picasso.get()
                .load(currentArticle.getImage())
                .placeholder(R.drawable.placeholder)
                .into(viewHolder.image);

        viewHolder.pubDate.setText(pubDateString);

        StringBuilder categories = new StringBuilder();
        for (int i = 0; i < currentArticle.getCategories().size(); i++) {
            if (i == currentArticle.getCategories().size() - 1) {
                categories.append(currentArticle.getCategories().get(i));
            } else {
                categories.append(currentArticle.getCategories().get(i)).append(", ");
            }
        }

        viewHolder.category.setText(categories.toString());

        viewHolder.itemView.setOnClickListener(new View.OnClickListener() {

            @SuppressLint("SetJavaScriptEnabled")
            @Override
            public void onClick(View view) {

                //show article content inside a dialog
                articleView = new WebView(mContext);

                articleView.getSettings().setLoadWithOverviewMode(true);

                String title = articles.get(viewHolder.getAdapterPosition()).getTitle();
                String content = articles.get(viewHolder.getAdapterPosition()).getContent();

                articleView.getSettings().setJavaScriptEnabled(true);
                articleView.setHorizontalScrollBarEnabled(false);
                articleView.setWebChromeClient(new WebChromeClient());
                articleView.loadDataWithBaseURL(null, "<style>img{display: inline; height: auto; max-width: 100%;} " +

                        "</style>\n" + "<style>iframe{ height: auto; width: auto;}" + "</style>\n" + content, null, "utf-8", null);

                AlertDialog alertDialog = new AlertDialog.Builder(mContext).create();
                alertDialog.setTitle(title);
                alertDialog.setView(articleView);
                alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                dialog.dismiss();
                            }
                        });
                alertDialog.show();

                ((TextView) alertDialog.findViewById(android.R.id.message)).setMovementMethod(LinkMovementMethod.getInstance());
            }
        });
    }

    @Override
    public int getItemCount() {
        return articles == null ? 0 : articles.size();
    }

    class ViewHolder extends RecyclerView.ViewHolder {
        TextView title;
        TextView pubDate;
        ImageView image;
        TextView category;

        public ViewHolder(View itemView) {

            super(itemView);
            title = itemView.findViewById(R.id.title);
            pubDate = itemView.findViewById(R.id.pubDate);
            image = itemView.findViewById(R.id.image);
            category = itemView.findViewById(R.id.categories);
        }
    }
}

标签： javaandroid

Answer 1

啊。给你。您正在尝试将 Recycler Adapter 转换为列表适配器。因此类转换异常。

您可以将列表视图替换为回收站视图。