我有一个帮助下载数据并将其存储在内容提供程序中的类，我有一个ListFragment，它从用户登录时加载来自提供程序的数据，下载数据并且一切正常，但是当数据有更新时，该类意味着下载数据并保存，但是当我调用ListFragment进行更新时，它会崩溃。任何帮助将不胜感激，我的代码如下：
这是下载数据的类
public class OrderDataRetrieval {
final Context context;
ProgressDialog pDiag;
public OrderDataRetrieval(final Context myContext){
context = myContext;
}
public void getData(String getToken, final Uri uri1, final Uri uri2, final Uri uri3){
pDiag = new ProgressDialog(context.getApplicationContext());
pDiag.setMessage("Loading...");
pDiag.setCancelable(false);
String order_URL = "http://xxxxxxxxxxxxxxxxx.json?token=" + getToken + "&contain=nnnnn,mmmm&uuuuu=0";
//pDiag.show();
Cache cache = AppController.getInstance().getRequestQueue().getCache();
final Entry entry = cache.get(order_URL);
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.GET,
order_URL, null,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
//pDiag.dismiss();
if (response != null) {
context.getContentResolver().delete(uri2, null, null);
context.getContentResolver().delete(uri3, null, null);
context.getContentResolver().delete(uri1, null, null);
Log.d("REPLY", response.toString());
handleResponse(response, uri1, uri2, uri3);
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// TODO Auto-generated method stub
//pDiag.dismiss();
}
});
// Adding request to request queue
AppController.getInstance().addToRequestQueue(jsonObjReq);
}
public void handleResponse(JSONObject response, Uri uri1, Uri uri2, Uri uri3){
try {
JSONObject respOrd = response.getJSONObject("response");
JSONObject dataOrd = respOrd.getJSONObject("data");
JSONArray ordersArr = dataOrd.getJSONArray("orders");
Log.d("TEST", uri1.toString());
Log.d("TAGURL", uri2.toString());
for (int i = 0; i < ordersArr.length(); i++) {
ContentValues value = new ContentValues();
JSONObject ordItmObj = (JSONObject) ordersArr.get(i);
final String id = ordItmObj.getString("id");
value.put("order_id", ordItmObj.getString("id"));
value.put("source_number", ordItmObj.getString("number"));
value.put("order_type", ordItmObj.getString("order_type"));
value.put("order_picked", ordItmObj.getString("picked"));
value.put("order_delivered", ordItmObj.getString("delivered"));
value.put("source_code", ordItmObj.getString("source_customer_code"));
value.put("source_email", ordItmObj.getString("source_customer_email"));
value.put("source_name", ordItmObj.getString("source_customer_name"));
value.put("source_phone", ordItmObj.getString("source_customer_phone_number"));
value.put("source_address", ordItmObj.getString("source_customer_address_line_1") + " " + ordItmObj.getString("source_customer_city"));
value.put("destination_code", ordItmObj.getString("destination_customer_code"));
value.put("destination_email", ordItmObj.getString("destination_customer_email"));
value.put("destination_name", ordItmObj.getString("destination_customer_name"));
value.put("destination_phone", ordItmObj.getString("destination_customer_phone_number"));
value.put("destination_address", ordItmObj.getString("destination_customer_address_line_1") + " " + ordItmObj.getString("destination_customer_city"));
context.getContentResolver().insert(uri1, value);
JSONArray ordItem = ordItmObj.getJSONArray("OrderItem");
for (int j = 0; j < ordItem.length(); j++) {
JSONObject itm = (JSONObject) ordItem.get(j);
ContentValues valueItem = new ContentValues();
valueItem.put("order_id", id);
valueItem.put("item_name", itm.getString("name"));
valueItem.put("item_quantity", itm.getString("quantity"));
valueItem.put("item_details", itm.getString("details"));
context.getContentResolver().insert(uri2, valueItem);
}
JSONArray ordIssues = ordItmObj.getJSONArray("Issue");
for (int h = 0; h < ordIssues.length(); h++) {
JSONObject issues = (JSONObject) ordIssues.get(h);
ContentValues valueIssues = new ContentValues();
valueIssues.put("order_id", id);
valueIssues.put("issue_type", issues.getString("issue_type_id"));
valueIssues.put("issue_description", issues.getString("description"));
context.getContentResolver().insert(uri3, valueIssues);
}
}
Intent intent = new Intent();
intent.setAction("RELOAD");
context.sendBroadcast(intent);
//pends.getActivity().
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
以下是需要更新的ListFragment，PendingFragment pends = PendingFragment.getInstance();
pends.getResults();调用该行时，它会崩溃应用
public class PendingFragment extends ListFragment{
Context activityContext;
private ProgressDialog pDialog;
private PendingOrderListAdapter listAdapter;
private List<PendingTrackItem> trackItems;
SharedPreferences pref;
private BroadcastReceiver myReciever = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
getResults();
}
};
public void onDestroyView() {
super.onDestroyView();
getActivity().getApplicationContext().unregisterReceiver(myReciever);
};
private static PendingFragment pending;
public PendingFragment(){
}
public static PendingFragment getInstance(){
if (null == pending) {
pending = new PendingFragment();
}
return pending;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View pending = inflater.inflate(R.layout.pending_frag, container, false);
setHasOptionsMenu(true);
return pending;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onViewCreated(view, savedInstanceState);
ListView list = getListView();
trackItems = new ArrayList<PendingTrackItem>();
listAdapter = new PendingOrderListAdapter(getActivity(), trackItems);
list.setAdapter(listAdapter);
list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
TextView add_id = (TextView) view.findViewById(R.id.orderId);
TextView orderNumber = (TextView) view.findViewById(R.id.orderNumber);
pref = getActivity().getSharedPreferences("myId", Context.MODE_PRIVATE);
Editor edit = pref.edit();
edit.putString("int1", add_id.getText().toString());
edit.commit();
Intent i = new Intent(getActivity(), OrderFragmentActivity.class);
i.putExtra("key1", orderNumber.getText().toString());
startActivity(i);
}
});
}
public void getResults(){
Uri uri = Uri.parse("content://" + getString(R.string.AUTORITY_ORDER) + "/order");
Log.d("URL PRINT", uri.toString());
final Cursor cursor = getActivity().getContentResolver().query(uri, null, null, null, "_id");
Log.d("CURSOR DATA:", cursor.toString());
JSONArray array = new JSONArray();
if (cursor != null && cursor.getCount() > 0) {
while(cursor.moveToNext()){
JSONObject object = new JSONObject();
try {
object.put("destination_address", cursor.getString(0));
object.put("destination_code", cursor.getString(1));
object.put("destination_email", cursor.getString(2));
object.put("destination_name", cursor.getString(3));
object.put("destination_phone", cursor.getString(4));
object.put("_id", cursor.getString(5));
object.put("order_delivered", cursor.getString(6));
object.put("order_id", cursor.getString(7));
object.put("order_picked", cursor.getString(8));
object.put("order_type", cursor.getString(9));
object.put("source_address", cursor.getString(10));
object.put("source_code", cursor.getString(11));
object.put("source_email", cursor.getString(12));
object.put("source_name", cursor.getString(13));
object.put("source_number", cursor.getString(14));
object.put("source_phone", cursor.getString(15));
array.put(object);
Log.d("ARRAY", String.valueOf(array.length()));
} catch (JSONException e) {
e.printStackTrace();
}
}
parseJsonFeed(array);
cursor.close();
/*FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ClosedFragment cF = new ClosedFragment();
ft.replace(android.R.id.list, cF);
ft.commit();
cF.getResults();*/
}
}
public void parseJsonFeed(JSONArray jArr){
Log.d("jsonArr", jArr.toString());
try {
trackItems.clear();
for (int i = 0; i < jArr.length(); i++) {
JSONObject rest = (JSONObject) jArr.get(i);
String check = rest.getString("order_delivered");
PendingTrackItem item = new PendingTrackItem();
String sourceAdrress, destinationAddress;
sourceAdrress = rest.getString("source_address");
destinationAddress = rest.getString("destination_address");
Log.d("ORDER_CHECK", rest.toString());
if (check.equals("false")) {
item.setId(rest.getString("order_id"));
item.setNumber(rest.getString("source_number"));
if (sourceAdrress.matches(" ")) {
item.setSourceAddress(rest.getString("destination_address"));
item.setSourceName(rest.getString("destination_name"));
} else if (destinationAddress.matches(" ")) {
item.setSourceAddress(rest.getString("source_address"));
item.setSourceName(rest.getString("source_name"));
} else {
item.setSourceAddress(rest.getString("source_address"));
item.setSourceName(rest.getString("source_name"));
}
trackItems.add(item);
}
}
//Log.d("ITEm", String.valueOf(trackItems.size()));
TextView txt = (TextView) getActivity().findViewById(R.id.txtCount);
txt.setText(String.valueOf(trackItems.size()));
listAdapter.notifyDataSetChanged();
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
@Override
public void onResume() {
// TODO Auto-generated method stub
activityContext = getActivity().getApplicationContext();
SharedPreferences pref = this.getActivity().getSharedPreferences("myData", Context.MODE_PRIVATE);
String getToken = pref.getString("key1", "no data");
IntentFilter filter = new IntentFilter("RELOAD");
getActivity().getApplicationContext().registerReceiver(myReciever, filter);
getResults();
//getData(getToken, uri, itemUri, issuesUri);
super.onResume();
}
}
崩溃报告
10-08 13:29:34.370: E/AndroidRuntime(9723): Process: com.deliveryscience.pod, PID: 9723
10-08 13:29:34.370: E/AndroidRuntime(9723): java.lang.IllegalStateException: Fragment PendingFragment{41f49628} not attached to Activity
10-08 13:29:34.370: E/AndroidRuntime(9723): at android.support.v4.app.Fragment.getResources(Fragment.java:603)
10-08 13:29:34.370: E/AndroidRuntime(9723): at android.support.v4.app.Fragment.getString(Fragment.java:625)
10-08 13:29:34.370: E/AndroidRuntime(9723): at com.deliveryscience.pod.fragments.PendingFragment.getResults(PendingFragment.java:109)
10-08 13:29:34.370: E/AndroidRuntime(9723): at com.deliveryscience.pod.handlers.OrderDataRetrieval.handleResponse(OrderDataRetrieval.java:122)
10-08 13:29:34.370: E/AndroidRuntime(9723): at com.deliveryscience.pod.handlers.OrderDataRetrieval$1.onResponse(OrderDataRetrieval.java:53)
10-08 13:29:34.370: E/AndroidRuntime(9723): at com.deliveryscience.pod.handlers.OrderDataRetrieval$1.onResponse(OrderDataRetrieval.java:1)
10-08 13:29:34.370: E/AndroidRuntime(9723): at com.android.volley.toolbox.JsonRequest.deliverResponse(JsonRequest.java:65)
10-08 13:29:34.370: E/AndroidRuntime(9723): at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
我很难找到一种方法来刷新ListFragment
答案 0 :(得分：0)
按照以下步骤
1）在ListFragment中注册广播接收器。
2）从下载数据类，发送一个广播消息，其注意事项与您注册接收器相同。
而不是代码，请使用sendBroadcast
PendingFragment pends = PendingFragment.getInstance();
pends.getResults();
3）从接收者类的onReceive进行必要的更新。
或者，您可以使用Handler在Download class和Fragment之间进行通信。
而不是