0 
public class MainActivity extends Activity {
    private static final String TAG = MainActivity.class.getSimpleName();
    private ListView listView;
    private FeedListAdapter listAdapter;
    private List<FeedItem> feedItems;
    private String URL_FEED = "http://myozawoo.esy.es/data.php";
    private String URL_FEED2 = "http://api.androidhive.info/feed/feed.json";

    private SwipeRefreshLayout swipeContainer;

//     String page = getIntent().getExtras().getString("page");
    @SuppressLint("NewApi")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 0);
        setContentView(R.layout.activity_main);

//        String page = getIntent().getExtras().getString("page");

        swipeContainer = (SwipeRefreshLayout) findViewById(R.id.swipeContainer);
        swipeContainer.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                parseJsonFeed();

            }
        });


        listView = (ListView) findViewById(R.id.list);

        feedItems = new ArrayList<FeedItem>();

        listAdapter = new FeedListAdapter(this, feedItems);
        listView.setAdapter(listAdapter);

        // These two lines not needed,
        // just to get the look of facebook (changing background color & hiding the icon)
//        getActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#3b5998")));
//        getActionBar().setIcon(
//                new ColorDrawable(getResources().getColor(android.R.color.transparent)));

        // We first check for cached request
//        Cache cache = AppController.getInstance().getRequestQueue().getCache();

        // Page One
        String page = getIntent().getExtras().getString("page");
        if(page.equals("1")) {
            Cache cache = AppController.getInstance().getRequestQueue().getCache();
            Entry entry = cache.get(URL_FEED);
            if (entry != null) {
                // fetch the data from cache
                try {
                    String data = new String(entry.data, "UTF-8");
                    try {
                        parseJsonFeed(new JSONObject(data));
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

            } else {
                // making fresh volley request and getting json
                JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET,
                        URL_FEED, null, new Response.Listener<JSONObject>() {

                    @Override
                    public void onResponse(JSONObject response) {
                        VolleyLog.d(TAG, "Response: " + response.toString());
                        if (response != null) {
                            parseJsonFeed(response);
                        }
                    }
                }, new Response.ErrorListener() {

                    @Override
                    public void onErrorResponse(VolleyError error) {
                        VolleyLog.d(TAG, "Error: " + error.getMessage());
                    }
                });

                // Adding request to volley request queue
                AppController.getInstance().addToRequestQueue(jsonReq);
            }
        }

        //Page Two

        else if (page.equals("2")) {
            Cache cache = AppController.getInstance().getRequestQueue().getCache();
            Entry entry = cache.get(URL_FEED2);
            if (entry != null) {
                // fetch the data from cache
                try {
                    String data = new String(entry.data, "UTF-8");
                    try {
                        parseJsonFeed(new JSONObject(data));
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

            } else {
                // making fresh volley request and getting json
                JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET,
                        URL_FEED2, null, new Response.Listener<JSONObject>() {

                    @Override
                    public void onResponse(JSONObject response) {
                        VolleyLog.d(TAG, "Response: " + response.toString());
                        if (response != null) {
                            parseJsonFeed(response);
                        }
                    }
                }, new Response.ErrorListener() {

                    @Override
                    public void onErrorResponse(VolleyError error) {
                        VolleyLog.d(TAG, "Error: " + error.getMessage());
                    }
                });

                // Adding request to volley request queue
                AppController.getInstance().addToRequestQueue(jsonReq);
            }
        }

        // Other Four Pages
        else {
            Cache cache = AppController.getInstance().getRequestQueue().getCache();
                Entry entry = cache.get(URL_FEED);
                if (entry != null) {
                    // fetch the data from cache
                    try {
                        String data = new String(entry.data, "UTF-8");
                        try {
                            parseJsonFeed(new JSONObject(data));
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    } catch (UnsupportedEncodingException e) {
                        e.printStackTrace();
                    }

                } else {
                    // making fresh volley request and getting json
                    JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET,
                            URL_FEED, null, new Response.Listener<JSONObject>() {

                        @Override
                        public void onResponse(JSONObject response) {
                            VolleyLog.d(TAG, "Response: " + response.toString());
                            if (response != null) {
                                parseJsonFeed(response);
                            }
                        }
                    }, new Response.ErrorListener() {

                        @Override
                        public void onErrorResponse(VolleyError error) {
                            VolleyLog.d(TAG, "Error: " + error.getMessage());
                        }
                    });

                    // Adding request to volley request queue
                    AppController.getInstance().addToRequestQueue(jsonReq);
                }

        }

        swipeContainer.setColorSchemeColors(android.R.color.holo_blue_bright,
                android.R.color.holo_green_light,
                android.R.color.holo_orange_light,
                android.R.color.holo_red_light);

    }





    /**
     * Parsing json reponse and passing the data to feed view list adapter
     * */
    public void parseJsonFeed(JSONObject response) {
        try {
//            String page = getIntent().getExtras().getString("page");
//            if (page.equals("1"))
            JSONArray feedArray = response.getJSONArray("feed");

            for (int i = 0; i < feedArray.length(); i++) {
                JSONObject feedObj = (JSONObject) feedArray.get(i);

                final FeedItem item = new FeedItem();
                item.setId(feedObj.getInt("id"));
                item.setName(feedObj.getString("name"));

                // Image might be null sometimes
                String image = feedObj.isNull("image") ? null : feedObj
                        .getString("image");
                item.setImge(image);
                item.setStatus(feedObj.getString("status"));
                item.setProfilePic(feedObj.getString("profilePic"));
                item.setTimeStamp(feedObj.getString("timeStamp"));

                // url might be null sometimes
                String feedUrl = feedObj.isNull("url") ? null : feedObj
                        .getString("url");
                item.setUrl(feedUrl);

                feedItems.add(item);
            }

            // notify data changes to list adapater
            listAdapter.notifyDataSetChanged();
        } catch (JSONException e) {
            e.printStackTrace();
        }

        swipeContainer.setRefreshing(false);
    }


}

我想刷新我的 ListView。现在，我无法刷新。不知道怎么刷新 如何在 onRefresh(){} 中执行。我不能将 parseJSON() 调用到 onRefresh(){}。请告诉我某人。非常感谢你！:-)

4

3 回答 3

1

在您的页面更改调用中，使用适配器清除 ListView 中的项目

listAdapter.clear();
adapter.notifyDataSetChanged();

如果您使用的是扩展 Android ArrayAdapter 的自定义适配器，您可能找不到 .clear()，因为私有类因实现而异。例如， .update()

无论如何，尝试在这里进行更改，看看它是否有效。

swipeContainer.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                // ---- RIGHT HERE THIS LINE     
                listAdapter.notifyDataSetChanged();
            }
        });
于 2014-11-22T14:39:43.593 回答
0

您在列表视图中使用了 adaper 作为

listAdapter = new FeedListAdapter(this, feedItems);
    listView.setAdapter(listAdapter);

现在更新其值后，您可以调用

listAdapter.notifyDataSetChanged();

您正在寻找刷新列表视图数据的方法，然后在适配器 notifyDataSetChanged();

在一小时内 pareseJsonFeed 更新

it...



    /**
     * Parsing json reponse and passing the data to feed view list adapter
     * */
    public void parseJsonFeed(JSONObject response) {
        try {
//            String page = getIntent().getExtras().getString("page");
//            if (page.equals("1"))
            JSONArray feedArray = response.getJSONArray("feed");

            for (int i = 0; i < feedArray.length(); i++) {
                JSONObject feedObj = (JSONObject) feedArray.get(i);

                final FeedItem item = new FeedItem();
                item.setId(feedObj.getInt("id"));
                item.setName(feedObj.getString("name"));

                // Image might be null sometimes
                String image = feedObj.isNull("image") ? null : feedObj
                        .getString("image");
                item.setImge(image);
                item.setStatus(feedObj.getString("status"));
                item.setProfilePic(feedObj.getString("profilePic"));
                item.setTimeStamp(feedObj.getString("timeStamp"));

                // url might be null sometimes
                String feedUrl = feedObj.isNull("url") ? null : feedObj
                        .getString("url");
                item.setUrl(feedUrl);

                feedItems.add(item);
            }
            listAdapter.clear();
            listAdapter.addAll(feedItems);
            // notify data changes to list adapater
            listAdapter.notifyDataSetChanged();
        } catch (JSONException e) {
            e.printStackTrace();
        }

        swipeContainer.setRefreshing(false);
    }


}
于 2014-11-22T14:46:15.850 回答
-1

当您再次调用服务器时，请尝试使您的缓存数据无效。这是最后一次通话AppController.getInstance().getRequestQueue().getCache().invalidate(key,boolean)

于 2016-02-24T09:31:42.207 回答