当我按下刷新按钮时，android sun app实时数据未加载到列表中
嗨我一直在关注android阳光Udacity课程，但我被困在加载来自互联网i日志的实时数据，我看到数据，但它没有加载在listView上提前感谢。
package com.example.ali.ican;
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 ForcastFragment())
.commit();
}
}
}
ForcastFragment
/**
* A placeholder fragment containing a simple view.
*/
public class ForcastFragment extends android.support.v4.app.Fragment {
private static ArrayAdapter<String> ForcastIncoming;
public ForcastFragment() {
}
//---------------------------------------------------------
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
new FetchWeatherTask().execute("London");
}
@Override
public void onCreateOptionsMenu(Menu menu,MenuInflater inflater) {
// Inflate the menu; this adds items to the action bar if it is present.
inflater.inflate(R.menu.forcastfragment, menu);
}
@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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_refresh) {
FetchWeatherTask fetchWeatherTask = new FetchWeatherTask();
fetchWeatherTask.execute("119505");
Log.v("Action_refresh","works");
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);
// api.openweathermap.org/data/2.5/forecast?q=Qazvin,Iran&mode=Json
// api.openweathermap.org/data/2.5/forecast/daily?q=Qazvin,Iran&mode=Json&units=metric&cnt=7
String [] wheather ={
"Today - sunny 88/66",
"Tommorow - foggy 65/66",
"Sunday - windy 55/63",
"Monday - cloudy 89/66"
};
List<String> WeekForecast =new ArrayList<String>(
Arrays.asList(wheather)
);
ForcastIncoming =
new ArrayAdapter<String>
(getActivity()
,R.layout.list_item_forcast,
R.id._list_item_forecast_textView,
WeekForecast);
ListView firstlist =(ListView) rootView.findViewById(R.id.list_view_foreccast);
firstlist.setAdapter(ForcastIncoming);
return rootView;
}
public class FetchWeatherTask extends AsyncTask<String ,Void, String[]>{
private final String LOG_TAG =FetchWeatherTask.class.getCanonicalName();
@Override
protected String[] doInBackground(String... params) {
Log.v("CityID",""+params);
// 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;
int numDays =7;
// 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
// final String FORCAST_BASE_URL ="http://api.openweathermap.org/data/2.5/forecast?id=119505&APPID=2a1ca9cdf8fa6bece6558112664c02ab";
final String FORCAST_BASE_URL ="http://api.openweathermap.org/data/2.5/forecast?id=119505&APPID=2a1ca9cdf8fa6bece6558112664c02ab";
final String QUERY_PARAM ="id";
final String QUERY_AAPID = "APPID";
final String APPID = "2a1ca9cdf8fa6bece6558112664c02ab";
final String QUERY_CNT = "cnt";
Uri uriBuilder = Uri.parse(FORCAST_BASE_URL).buildUpon()
.appendQueryParameter(QUERY_PARAM,params[0])
.appendQueryParameter(QUERY_AAPID,APPID)
.appendQueryParameter(QUERY_CNT,Integer.toString(numDays))
.build();
// URL url = new URL("http://api.openweathermap.org/data/2.5/forecast?id=119505&APPID=2a1ca9cdf8fa6bece6558112664c02ab");
URL url = new URL(uriBuilder.toString());
Log.v("Uri_builder",""+uriBuilder);
// Create the request to OpenWeatherMap, and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
// urlConnection.setRequestProperty("User-Agent","Mozilla/5.0 ( compatible ) ");
// urlConnection.setRequestProperty("Accept","*/*");
// urlConnection.setRequestProperty("API_KEY", "2a1ca9cdf8fa6bece6558112664c02ab");
// urlConnection.setDoInput(true);
// urlConnection.setDoOutput(false);
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
Log.e("inputstreamshouting","yesssssssssnullllllllll");
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();
Log.v("MAhdi","forcastJsonStr:" +forecastJsonStr);
} catch (IOException e) {
Log.e("PlaceholderFragment", "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("PlaceholderFragment", "Error closing stream", e);
}
}
}
try {
return getWeatherDataFromJson(forecastJsonStr,numDays);
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String[] res) {
super.onPostExecute(res);
Log.v("From_onPost",""+res);
if (res !=null)
{
ForcastIncoming.clear();
for(String dayForcastTR :res){
ForcastIncoming.add(dayForcastTR);
}
}
ForcastIncoming.notifyDataSetChanged();
}
/* The date/time conversion code is going to be moved outside the asynctask later,
* so for convenience we're breaking it out into its own method now.
*/
private String getReadableDateString(long time){
// Because the API returns a unix timestamp (measured in seconds),
// it must be converted to milliseconds in order to be converted to valid date.
Date date = new Date(time * 1000);
SimpleDateFormat format = new SimpleDateFormat("E, MMM d");
return format.format(date).toString();
}
/**
* Prepare the weather high/lows for presentation.
*/
private String formatHighLows(double high, double low) {
// For presentation, assume the user doesn't care about tenths of a degree.
long roundedHigh = Math.round(high);
long roundedLow = Math.round(low);
String highLowStr = roundedHigh + "/" + roundedLow;
return highLowStr;
}
/**
* Take the String representing the complete forecast in JSON Format and
* pull out the data we need to construct the Strings needed for the wireframes.
*
* Fortunately parsing is easy: constructor takes the JSON string and converts it
* into an Object hierarchy for us.
*/
private String[] getWeatherDataFromJson(String forecastJsonStr, int numDays)
throws JSONException {
Log.v("Testing_arg","this is the ::"+ forecastJsonStr);
// These are the names of the JSON objects that need to be extracted.
final String OWM_LIST = "list";
final String OWM_WEATHER = "weather";
final String OWM_TEMPERATURE = "temp";
final String OWM_MAX = "temp_max";
final String OWM_MIN = "temp_min";
final String OWM_DATETIME = "dt";
final String OWM_DESCRIPTION = "main";
JSONObject forecastJson = new JSONObject(forecastJsonStr);
JSONArray weatherArray = forecastJson.getJSONArray(OWM_LIST);
String[] resultStrs = new String[numDays];
Log.v("here_weatherArray","works ::"+ weatherArray);
for(int i = 0; i < weatherArray.length(); i++) {
// For now, using the format "Day, description, hi/low"
String day;
String description;
String highAndLow;
// Get the JSON object representing the day
JSONObject dayForecast = weatherArray.getJSONObject(i);
Log.v("here_dayForecast","works ::"+dayForecast);
// The date/time is returned as a long. We need to convert that
// into something human-readable, since most people won't read "1400356800" as
// "this saturday".
long dateTime = dayForecast.getLong(OWM_DATETIME);
day = getReadableDateString(dateTime);
// description is in a child array called "weather", which is 1 element long.
JSONObject weatherObject = dayForecast.getJSONArray(OWM_WEATHER).getJSONObject(0);
description = weatherObject.getString(OWM_DESCRIPTION);
Log.v("herewat","worksk ::" + weatherObject);
// Temperatures are in a child object called "temp". Try not to name variables
// "temp" when working with temperature. It confuses everybody.
JSONObject temperatureObject = dayForecast.getJSONObject(OWM_DESCRIPTION);
double high = temperatureObject.getDouble(OWM_MAX);
double low = temperatureObject.getDouble(OWM_MIN);
Log.v("high","temperatureObject ::"+high);
highAndLow = formatHighLows(high, low);
resultStrs[i] = day + " - " + description + " - " + highAndLow;
Log.v("_resultStrs","works ::"+resultStrs);
// Log.v("resultStrs[i]","this is the ::"+ resultStrs[i]);
// for(int ii=0;ii<resultStrs.length;i++){
//
// Log.v("_Parsing", "Forcast entry: " + resultStrs[ii]);
//
//
// }
return resultStrs;
}
return resultStrs;
}
}
}
我希望有人可以提前再次感谢我
布局结构
1 个答案:
答案 0 :(得分：1)
将您的List<String> WeekForecast设为全局，并在onPostExecute中添加新项目，如
@Override
protected void onPostExecute(String[] res) {
super.onPostExecute(res);
Log.v("From_onPost",""+res);
if (res !=null)
{
WeekForecast.clear();
WeekForecast.addAll(Arrays.asList(res));
ForcastIncoming.notifyDataSetChanged();
}
}
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