【发布时间】：2013-10-04 11:24:30
【问题描述】：
我正在尝试从循环中调用 AsyncTask。它工作正常，但问题是执行所有请求需要更多时间。请建议我如何让它更快。
for (int i = 0; i < 6; i++) {
response = requestWeatherUpdate(location);
}
请求天气更新
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();
if (weatherRequestResponse != "") {
parsedWeatherResponse = ParseWeatherResponseXML
.parseMyTripXML(weatherRequestResponse);
}
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return parsedWeatherResponse;
}
使用回调
public class WeatherUpdateAsyncTask extends AsyncTask<String, Void, String> {
Context context;
CallBack callBack;
public WeatherUpdateAsyncTask(CallBack callBack) {
this.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) {
// TODO Auto-generated method stub
super.onPostExecute(result);
callBack.run(result);
}
}
请求天气更新
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;
}
我在这里打电话
for (int i = 0; i < 4; 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);
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("");//Here i have set the values from the response i recived from the AsynkTask
humidity.setText("");//Here i have set the values from the response i recived from the AsynkTask
flight_depart_image.setImageResource(R.drawable.f1);
depart_arrivals_details.addView(layout, i);
}
【问题讨论】：
-
你能详细说明为什么你需要循环异步吗？
-
如果您使用的是 4.0 或更高版本的异步任务，按调用顺序执行，而不是同时执行。尝试像这样执行：“AsyncTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, "");"
-
看到问题是我在 for 循环中调用 asynk 任务需要更多时间，所以有什么方法可以减少执行时间
-
@invisbo 你的意思是通过调用 execute() 他们将在同一个线程中依次运行？
-
@Rahul 是的，没错