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问题描述
我尝试创建一个应用程序，它会更新多个城市。每行的天气将有不同势温度，所以我有使用AsynkTask。但我无法得到来自API的响应之后，更新UI。
I am try to create a application that will update the weather of multiple cities .Each row will have diffrent temp so i have use a AsynkTask. But i am not able to update the UI after getting the response from the API.
我的主要活动
public class MainActivity extends Activity {
LinearLayout depart_arrivals_details;
LayoutInflater inflater;
TextView depart_time,
depart_airport_city, depart_airport, arrival_time,
arrival_airport_city, arrival_airport, pnr_number,temprature,humidity;
ImageView flight_depart_image;
public static String url = "";
WeatherResponse response;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
depart_arrivals_details = (LinearLayout) findViewById(R.id.depart_arrivals_details);
inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
setSectorData();
}
void setSectorData() {
for (int i = 0; i < 1; i++) {
inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
RelativeLayout layout = (RelativeLayout) inflater.inflate(
R.layout.sector_details, depart_arrivals_details, false);
depart_time = (TextView)layout.findViewById(R.id.depart_time);
depart_airport_city = (TextView)layout.findViewById(R.id.depart_airport_city);
temprature = (TextView)layout.findViewById(R.id.temprature);
humidity = (TextView)layout.findViewById(R.id.humidity);
flight_depart_image = (ImageView)layout.findViewById(R.id.flight_depart_image);
WeatherResponse responseUpdate = requestWeatherUpdate("DEL");
depart_time.setText("20:45");
depart_airport_city.setText("Mumbai");
/*
* This part will be updated when we will se the request and get the response
* then we have to set the temp and humidity for each city that we have recived
* */
temprature.setText(responseUpdate.getTempInC()+(char) 0x00B0);//Here it is showing null pointer exception after that the respone is coming from the server .So can we do this
humidity.setText(responseUpdate.getHumidity());
flight_depart_image.setImageResource(R.drawable.f1);
depart_arrivals_details.addView(layout, i);
}
}
/*
* Here the location will be dynamic and have to send the request for all the location i have
* */
private WeatherResponse requestWeatherUpdate(String location) {
url = "http://api.worldweatheronline.com/free/v1/weather.ashx?&format=xml&num_of_days=2&key=uysakmq923nbd5y549yz3aaw&q="
+ location;
Log.d("URL for Weather Upadate", url);
WeatherUpdateAsyncTask weatherReq = new WeatherUpdateAsyncTask(new CallBack() {
@Override
public void run(Object result) {
try {
String AppResponse = (String) result;
response = ParseWeatherResponseXML
.parseMyTripXML(AppResponse);
} catch (Exception e) {
Log.e("TAG Exception Occured",
"Exception is " + e.getMessage());
}
}
});
weatherReq.execute(url);
return response;
}
这是我的 requestWeatherUpdate
private WeatherResponse requestWeatherUpdate(String location) {
url = ""
+ location;
Log.d("URL for Weather Upadate", url);
WeatherUpdateAsyncTask weatherReq = new WeatherUpdateAsyncTask(new CallBack() {
@Override
public void run(Object result) {
try {
String AppResponse = (String) result;
response = ParseWeatherResponseXML
.parseMyTripXML(AppResponse);
} catch (Exception e) {
Log.e("TAG Exception Occured",
"Exception is " + e.getMessage());
}
}
});
weatherReq.execute(url);
return response;
}
如果我尝试设置我收到抛出空指针异常值
And if i try to set the value that i have recieved is throwing null pointer exception
推荐答案
试试这个
首先在 for循环
depart_arrivals_details.removeAllViews();
for (int i = 0; i < 2; i++) {
requestWeatherUpdate("BLR");
}
功能WeatherResponse
private WeatherResponse requestWeatherUpdate(String location) {
url = ""
+ location;
Log.d("URL for Weather Upadate", url);
WeatherUpdateAsyncTask weatherReq = new WeatherUpdateAsyncTask();
String weatherRequestResponse="";
try {
weatherRequestResponse=weatherReq.execute(url).get();
parsedWeatherResponse = ParseWeatherResponseXML
.parseMyTripXML(weatherRequestResponse);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return parsedWeatherResponse;
}
和和 AsynkTask
public class WeatherUpdateAsyncTask extends AsyncTask<String, Void, String> {
Context context;
CallBack callBack;
@Override
protected String doInBackground(String... arg0) {
String responseString = "";
HttpClient client = null;
try {
client = new DefaultHttpClient();
HttpGet get = new HttpGet(arg0[0]);
client.getParams().setParameter("http.socket.timeout", 6000);
client.getParams().setParameter("http.connection.timeout", 6000);
HttpResponse responseGet = client.execute(get);
HttpEntity resEntityGet = responseGet.getEntity();
if (resEntityGet != null) {
responseString = EntityUtils.toString(resEntityGet);
Log.i("GET RESPONSE", responseString.trim());
}
} catch (Exception e) {
Log.d("ANDRO_ASYNC_ERROR", "Error is " + e.toString());
}
Log.d("ANDRO_ASYNC_RESPONSE", responseString.trim());
client.getConnectionManager().shutdown();
return responseString.trim();
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
}
}
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