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[英]How to call a method inside a method, on click of a button? (Android Java)
[英]Android: how to restart a method with a button click
我有一個按鈕,它從微調器中獲取月份和年份,然后調用異步任務,該任務讀取json數據。 那部分工作正常,但是如果我嘗試更改月份和年份,然后再次單擊該按鈕,則無濟於事。 我必須按返回以重新加載頁面,然后再次單擊該按鈕才能獲得不同的結果。 這是我的代碼。 你們中任何一個聰明的人可以幫我嗎。
package com.app.simplictyPortal;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.app.simplicityPortal.adapter.InvoiceAdapter;
import android.app.Fragment;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Spinner;
public class InvoiceFragment extends Fragment {
public InvoiceFragment(){}
Button load;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_invoice, container, false);
ArrayList<String> years = new ArrayList<String>();
int thisYear = Calendar.getInstance().get(Calendar.YEAR);
int currentMonth = Calendar.getInstance().get(Calendar.MONTH);
for (int i = 2013; i <= thisYear; i++)
{
years.add(Integer.toString(i));
}
//String tmonth = Integer.toString(currentMonth);
String tyear = Integer.toString(thisYear);
final Spinner year = (Spinner)rootView.findViewById(R.id.spinner1);
final Spinner month = (Spinner)rootView.findViewById(R.id.spinner2);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_spinner_item, years);
// Specify the layout to use when the list of choices appears
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Apply the adapter to the spinner
year.setAdapter(adapter);
year.setSelection(adapter.getPosition(tyear));
ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(getActivity(),
R.array.month, android.R.layout.simple_spinner_item);
// Specify the layout to use when the list of choices appears
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Apply the adapter to the spinner
month.setAdapter(adapter2);
month.setSelection(currentMonth);
load=(Button)rootView.findViewById(R.id.button1);
load.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String y = (String) year.getSelectedItem();
int im = month.getSelectedItemPosition();
String m = Integer.toString(im +1);
final GlobalClass globalVariable = (GlobalClass) getActivity().getApplicationContext();
final String Compid = globalVariable.getCompid();
new InvoiceAsyncTask().execute("http://dev-sql1:8080/api/invoice/getall/"+Compid+"?m="+m+"&y="+y);
}
});
return rootView;
}
public void invoice(JSONArray jArray) {
ListView lv = (ListView) getView().findViewById(R.id.listView1);
List<ListViewItem> items = new ArrayList<InvoiceFragment.ListViewItem>();
try {
for (int i = 0; i <jArray.length(); i++) {
final JSONObject json_data = jArray.getJSONObject(i);
items.add(new ListViewItem()
{{
Vendor= json_data.optString("CarrierName");
Bill = "$ " + json_data.optString("BillAmount");
Serviceacct = json_data.optString("ServiceAccountNumber");
Date = json_data.optString("ReceivedDate");
}});
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
InvoiceAdapter adapter = new InvoiceAdapter(getActivity(), items);
lv.setAdapter(adapter);
// TODO Auto-generated method stub
}
public class ListViewItem
{
public String Vendor;
public String Bill;
public String Serviceacct;
public String Date;
} public static String GET(String url){
InputStream inputStream = null;
String result = "";
try {
// create HttpClient
HttpClient httpclient = new DefaultHttpClient();
// make GET request to the given URL
HttpResponse httpResponse = httpclient.execute(new HttpGet(url));
// receive response as inputStream
inputStream = httpResponse.getEntity().getContent();
// convert inputstream to string
if(inputStream != null)
result = convertInputStreamToString(inputStream);
else
result = "Did not work!";
} catch (Exception e) {
Log.d("InputStream", e.getLocalizedMessage());
}
return result;
}
private static String convertInputStreamToString(InputStream inputStream) throws IOException{
BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
String line = "";
String result = "";
while((line = bufferedReader.readLine()) != null)
result += line;
inputStream.close();
return result;
}
public class InvoiceAsyncTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
return GET(urls[0]);
}
// onPostExecute displays the results of the AsyncTask.
@Override
protected void onPostExecute(String result) {
try {
JSONArray jArray = new JSONArray(result);
invoice(jArray);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
您如何處理InvoiceAsyncTask的結果? 您是否實現了從AsyncTask的onPostExecute()到活動的回調?
也許下面的示例將為您提供幫助。
首先,使用回調接口實現AsyncTask類:
public class ServerRequestAsyncTask extends AsyncTask<String, Void, ServerResponseDetails> {
public ServerRequestAsyncTask(Fragment fragment, ServerRequestDetails request) {
mFragment = fragment;
mRequest = request;
}
public interface OnServerRequestAsyncTaskCompletedListener {
void onServerRequestAsyncTaskCompleted(ServerResponseDetails response);
}
public void cancel() {
if (mHttpGet != null && !mHttpGet.isAborted()) mHttpGet.abort();
cancel(true);
}
並添加onPostExecute():
@Override
protected void onPostExecute(ServerResponseDetails response) {
if (mFragment != null) mFragment.onServerRequestAsyncTaskCompleted(response);
}
我從Fragment調用AsyncTask,但是您可以將其與Activity結合使用。 然后,在“活動”中實現接口:
@Override
public void onServerRequestAsyncTaskCompleted(ServerResponseDetails response) {
// do what you need here, then 'finish' task by setting mServerRequest to null
mServerRequest = null;
}
並執行AsyncTask:
protected ServerRequestAsyncTask mServerRequest = null;
public boolean isServerRequestRunning() {
return (mServerRequest != null);
}
public void cancelServerRequest() {
mServerRequest.cancel();
}
public void sendServerRequest(Fragment fragment, ServerRequestDetails request) {
if (Application.isNetworkAvailable()) {
if (!isServerRequestRunning()) {
mServerRequest = new ServerRequestAsyncTask(fragment, request);
mServerRequest.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
{params});
}
}
}
mServerRequest變量保存對當前執行任務的引用。 如果需要中止,可以調用mServerRequest.cancel()。
謝謝大家,但我已經弄清楚了。 我需要在post execute方法中取消Async任務。
@Override
protected void onPostExecute(String result) {
try {
JSONArray jArray = new JSONArray(result);
invoice(jArray);
cancel(true);
isCancelled();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
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