Question

我正在从我的片段进行API调用并使用volley获取响应。每次单击该片段选项卡时，都会再次进行API调用。我希望API调用只进行一次。有没有办法实现这个目标？我试着寻找解决方案，但没有找到任何有用的东西。下面是我片段的代码。

public class Tab3News extends Fragment {

    private RecyclerView newsView;
    private NewsAdapter newsadapter;
    String myxmlResponse;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        Log.d("Making request again","hello");
        View layout = inflater.inflate(R.layout.tab3news, container, false);
        newsView = (RecyclerView) layout.findViewById(R.id.newstable);
        String symPassed = ((SendString)getActivity()).message;

        String XmlURL = "http://demoapplication-env.us-east-2.elasticbeanstalk.com/?symbol="+symPassed+"&indicator=XML";


        RequestQueue queue = Volley.newRequestQueue(getActivity().getApplicationContext());

        StringRequest req = new StringRequest(Request.Method.GET, XmlURL,
                new Response.Listener<String>()
                {
                    @Override
                    public void onResponse(String response) {
                        try {
                            //processData(response);

                            myxmlResponse = response;

                            newsView.setHasFixedSize(true);
                            //newsView.setItemAnimator(new DefaultItemAnimator());
                            newsView.setLayoutManager(new LinearLayoutManager(getActivity()));
                            newsView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL_LIST));
                            newsadapter = new NewsAdapter(getActivity(),getData());
                            newsView.setAdapter(newsadapter);

                        } catch (UnsupportedEncodingException e) {
                            e.printStackTrace();
                        } catch (XmlPullParserException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener()
                {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        // handle error response
                    }
                }
        );
        queue.add(req);


        return layout;
    }
}

Answer 1

有两种方法可以做到这一点 -

1-从此片段的父活动中调用API，并相应地使用“setArguments(bundle)”将数据传递给片段，这样，每次加载片段时都不会调用API。 / p>

2-每当调用API时，在Preference中保留一个布尔值 -

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
{
        mMyPrefs = PreferenceManager.getDefaultSharedPreferences(this);
        boolean isFirstTime = mMyPrefs.getBoolean("IS_FIRST_TIME", true);
       if (mIsFirstTime)
                    {
                        SharedPreferences.Editor editPrefs = mMyPrefs.edit();
                        editPrefs.putBoolean("IS_FIRST_TIME", false);
                        editPrefs.apply();

                        callAPI();
                    }
      else
      {
             //TO DO YOUR STUFF
      }
}

Answer 2

我认为最好在活动中调用api并通过bundle传递参数，而不是在共享首选项中使用标志。再一次，这是我个人的看法。

Api使用Volley从一个片段调用

2 个答案: