android - onRefresh Android SwipeRefreshLayout 不调用我的方法

Question

我正在学习 android 滑动刷新布局。我在 swipeRefreshLayout“setRefreshing(true)”上发布了 runabble，然后在 onRefresh 方法上我写了 fetchMovie()。但是 fetchMovie() 没有调用。如何解决？

package com.example.zihadrizkyef.belajarswiperefresh;

import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.example.zihadrizkyef.belajarswiperefresh.app.MyApplication;
import com.example.zihadrizkyef.belajarswiperefresh.helper.Movie;
import com.example.zihadrizkyef.belajarswiperefresh.helper.SwipeListAdapter;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity implements SwipeRefreshLayout.OnRefreshListener {
    private String TAG = MainActivity.class.getSimpleName();
    private String URL_TOP_250 = "http://api.androidhive.info/json/imdb_top_250.php?offset=";
    private SwipeRefreshLayout swipeRefreshLayout;
    private ListView listView;
    private SwipeListAdapter adapter;
    private List<Movie> movieList;
    private int offSet = 0;

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

        listView = (ListView) findViewById(R.id.listView);
        swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipe_refresh_layout);

        movieList = new ArrayList<Movie>();
        adapter = new SwipeListAdapter(this, movieList);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(MainActivity.this, "aaaaaaaaaa", Toast.LENGTH_SHORT).show();
            }
        });

        swipeRefreshLayout.setOnRefreshListener(this);

        swipeRefreshLayout.post(new Runnable() {
            @Override
            public void run() {
                swipeRefreshLayout.setRefreshing(true);
            }
        });
    }

    @Override
    public void onRefresh() {
        fetchMovie();
    }

    private void fetchMovie() {
        swipeRefreshLayout.setRefreshing(true);
        String url = URL_TOP_250+offSet;

        JsonArrayRequest req = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
            @Override
            public void onResponse(JSONArray response) {
                System.out.println(TAG+response.toString());

                if (response.length() > 0) {
                    for (int i=0; i<=response.length(); i++) {
                        try {
                            JSONObject movieObject = response.getJSONObject(i);
                            int rank = movieObject.getInt("rank");
                            String title = movieObject.getString("title");

                            Movie movie = new Movie(rank, title);
                            movieList.add(0, movie);

                            if (rank > offSet) {
                                offSet = rank;
                            }
                        } catch (JSONException e) {
                            System.out.println(TAG + " : JSON Parsing error : "+e.getMessage());
                        }
                    }
                    adapter.notifyDataSetChanged();
                }
                swipeRefreshLayout.setRefreshing(false);
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                System.out.println(TAG+" : Server error : "+error.getMessage());
                Toast.makeText(MainActivity.this, error.getMessage(), Toast.LENGTH_SHORT).show();
                swipeRefreshLayout.setRefreshing(false);
            }
        });

        MyApplication.getInstance().addToRequestQueue(req);
    }
}

Answer 1

如有关SwipeRefreshLayout 的文档中所示:

If an activity wishes to show just the progress animation, it should call setRefreshing(true).

调用 setRefreshing() 不会调用 OnRefreshListener。你可以在它之后调用 fetchMovie() :

swipeRefreshLayout.post(new Runnable() {
            @Override
            public void run() {
                swipeRefreshLayout.setRefreshing(true);
                fetchMovie();
            }
        });

相关文档:https://developer.android.com/reference/android/support/v4/widget/SwipeRefreshLayout.html