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ListView。现在，我无法刷新。我不知道如何刷新。如何在onRefresh（）{}中完成。我无法将parseJSON（）调用到onRefresh（）{}。请告诉我一个人。非常感谢你！ ： - ）
答案 0 :(得分：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，则可能找不到.clear（），因为私有类会因实现而异。例如，.update（）
无论如何，请尝试在此处进行更改，看看它是否有效。
swipeContainer.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
// ---- RIGHT HERE THIS LINE
listAdapter.notifyDataSetChanged();
}
});
答案 1 :(得分：0)
您已在列表视图中使用adaper作为
listAdapter = new FeedListAdapter(this, feedItems);
listView.setAdapter(listAdapter);
现在，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（）中找到它的方法;
小时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);
}
}
答案 2 :(得分：-1)
尝试使您的缓存数据无效，这是您再次呼叫服务器时的情况。这是AppController.getInstance().getRequestQueue().getCache().invalidate(key,boolean)