我在android中创建了一个小程序来同步来自云的数据但是每当我按下刷新按钮（用于开发目的）时代码都没有响应.. Logcat显示：
02-25 22:57:32.195: W/InputEventReceiver(17762): Attempted to finish an input event but the input event receiver has already been disposed.
MainActivity和FragmentActivity类的java代码如下所示
package sunshine.com.example.himanshu.sunshine;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction().add(R.id.container, new ForecastFragment()).commit(); }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
package sunshine.com.example.himanshu.sunshine;
import android.annotation.TargetApi;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
/**
* Created by Himanshu on 2/25/2015.
*/
public class ForecastFragment extends Fragment
{
public ForecastFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.forecast_fragment,menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id=item.getItemId();
if(id==R.id.refresh_action)
{
FetchWeatherTask fetch=new FetchWeatherTask();
fetch.execute("716217");
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
String forecastArray[] =
{ "Today-sunny-23/34",
"Tomorrow-foggy-45/67",
"Wed-asteroid-54/34",
"Thursday--sunny-34/56",
"Fri-foggy-45/34"
, "Sat-day-23/45"
, "Sun-Sunny-34/65",
"Someday-gloomy-78/90",
"Sat-day-23/45",
"Wed-asteroid-54/34",
"Today-sunny-23/34" };
List<String> weekForecast = new ArrayList<String>(Arrays.asList(forecastArray));
ArrayAdapter<String> mForecastAdapter = new ArrayAdapter<String>(getActivity(), R.layout.list_item_forecast, R.id.list_item_forecast_textview, weekForecast);
ListView listView = (ListView) rootView.findViewById(R.id.listview_forecast);
listView.setAdapter(mForecastAdapter);
return rootView;
}
public class FetchWeatherTask extends AsyncTask<String, Void, Void> {
private final String LOG_TAG = FetchWeatherTask.class.getSimpleName();
@Override
protected Void doInBackground(String... params)
{
if(params.length==0)
return null;
// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
// Will contain the raw JSON response as a string.
String forecastJsonStr = null;
try {
// Construct the URL for the OpenWeatherMap query
// Possible parameters are avaiable at OWM's forecast API page, at
// http://openweathermap.org/API#forecast
String format="json";
String unit="metric";
int days=7;
final String surl="http://api.openweathermap.org/data/2.5/forecast/daily?";
final String pcode="q";
final String mode="mode";
final String units="units";
final String daysy="cnt";
Uri urlbulilt=Uri.parse(surl).buildUpon().appendQueryParameter(pcode,params[0])
.appendQueryParameter(mode,format)
.appendQueryParameter(units,unit)
.appendQueryParameter(daysy,Integer.toString(days)).build();
URL url=new URL(urlbulilt.toString());
// Create the request to OpenWeatherMap, and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
forecastJsonStr = buffer.toString();
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's no point in attemping
// to parse it.
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e(LOG_TAG, "Error closing stream", e);
}
}
}
return null;
}
}
}
答案 0 :(得分：1)
我认为这是因为你的fetch对象是onOptionsItemSelected（）方法的局部变量，到AsyncTask完成时它已被垃圾收集。
尝试将其设为字段，然后在onOptionsItemSelected（）方法
中指定它public class ForecastFragment extends Fragment {
private FetchWeatherTask fetch;
public ForecastFragment() {
}
...
然后
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id=item.getItemId();
if(id==R.id.refresh_action)
{
fetch=new FetchWeatherTask();
fetch.execute("716217");
return true;
}
return super.onOptionsItemSelected(item);
}
现在，当AsyncTask完成时，你的fetch对象应该仍然存在。