Question

我需要帮助，以找到一种根据用户选择更改RecyclerView内容的方法。我正在制作一个Android应用，默认情况下显示来自abc新闻的新闻，但我想让用户选择其他来源，例如cnn等。我在微调器中有此选项，并在其中叫onItemSelected()可以获取用户选择的来源。使用新的源，我调用loadNews（Source）方法，该方法向新闻api发出请求并获取数据。我将发布我的代码，希望有人能提供帮助。截至目前，当我打开新闻活动时，它会从abc加载新闻，但是当我选择另一个来源时，它不会从其他来源重新加载数据，它将保持相同的内容！

活动代码

private String Source ="abc-news";
private Spinner spinner;

private List<Article> articles;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_news);

    // getting the news service
    newsService = Common.getNewsService();
    recyclerView = findViewById(R.id.recyclerView);
    kbv = findViewById(R.id.kbv);
    swipeRefreshLayout = findViewById(R.id.swipeRefresh);
    spinner  =(Spinner)findViewById(R.id.drop_Down_News_Source);

    loadSpinner();


    // originally load from abc news and if user wants to change they can select from the list and reload the news
    // initialize the recycler
    loadNews(this.Source);


    swipeRefreshLayout.setOnRefreshListener(new   SwipeRefreshLayout.OnRefreshListener() {
        @TargetApi(Build.VERSION_CODES.P)
        @RequiresApi(api = Build.VERSION_CODES.P)
        @Override
        public void onRefresh() {
            loadNews(Source);
            new Handler().postDelayed(new Runnable() {
                @Override
                public void run() {
                    swipeRefreshLayout.setRefreshing(false);
                }
            },4000);

        }
    });


}

private void loadSpinner() {

    ArrayAdapter<CharSequence> myAdapter = ArrayAdapter.createFromResource(this,R.array.News_Sources, android.R.layout.simple_spinner_item);
    myAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(myAdapter);

}


public void loadNews(String Source){
    newsService.getArticles(Common.getAPIUrl(Source)).enqueue(new Callback<News>() {
        @Override
        public void onResponse(Call<News> call, Response<News> response) {
            Picasso.get()
                    .load(response.body().getArticles().get(0).getUrlToImage())
                    .into(kbv);

            articles = response.body().getArticles();

            articles.remove(0);
            RecyclerViewAdapter adapter = new RecyclerViewAdapter(newsActivity.this, articles, newsActivity.this);
            recyclerView.setAdapter(adapter);
            recyclerView.setLayoutManager(new LinearLayoutManager(newsActivity.this));
        }

        @Override
        public void onFailure(Call<News> call, Throwable t) {
            Toast.makeText(newsActivity.this,"Something went wrong!!!", Toast.LENGTH_SHORT).show();
        }
    });
}

@Override
public void onClickListener(View view, int position) {
if(articles != null && view != null){
    Intent intent = new Intent(newsActivity.this, webviewClass.class);
    intent.putExtra("article_url", articles.get(position).getUrl());
    startActivity(intent);
}
else{
    Toast.makeText(this, "something went wrong in clickListener  method!", Toast.LENGTH_SHORT);
}
}

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
  switch (position){
      case 0 :
          Source = "cbs-news";
          break;
      case 1 :
          Source = "espn";
          break;
      case 2:
          Source ="cnn";
          break;
      case 3:
          Source = "mtv-news";
          break;
      case 4:
          Source = "nbc-news";
          break;
          default:
              Source ="abc-news";
  }
  loadNews(Source);
}

Answer 1

我认为您没有为微调器设置监听器。

spinner.setOnItemSelectedListener(this);

Answer 2

您的微调器没有用于侦听值更改的侦听器。在将适配器设置为微调器之后，添加这段代码。

spinner.setOnItemSelectedListener(this);

此外，您的活动现在也将实现微调器的itemSelected侦听器。

希望有帮助。：）

根据用户输入的android更改recyclerview的内容

2 个答案: