從異步任務中獲取LatLngs

Question

我已經成功實現了新的Google Maps Roads API以將我的位置更新爲Long ..它在我使用asyncTask.execute.get（）時正常工作，但它凍結了我的UI .. 我想要要知道如何將我的結果傳遞給來自異步任務的LatLng對象，因爲它必須每2秒運行一次才能獲得新的Lat Long。

MapsActivity.class

package com.example.akshay.roadsapi; 

import android.app.Activity; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Bundle; 
import android.support.v4.app.FragmentActivity; 

import com.google.android.gms.maps.GoogleMap; 
import com.google.android.gms.maps.SupportMapFragment; 
import com.google.android.gms.maps.model.LatLng; 
import com.google.android.gms.maps.model.MarkerOptions; 

import java.util.concurrent.ExecutionException; 

public class MapsActivity extends FragmentActivity { 

    private GoogleMap mMap; // Might be null if Google Play services APK is not available. 
    final String URL = "https://roads.googleapis.com/v1/snapToRoads?path="; 
    final String KEY = "MYAPK KEY HERE"; 
    int i = 0; 
    LatLng latLng1 = null; 
    Activity activity; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_maps); 
     mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap(); 
     final LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE); 
     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 60000, 0, new LocationListener() { 
      @Override 
      public void onLocationChanged(Location location) { 

       LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude()); 

       BackgroundTask backgroundTask = new BackgroundTask(MapsActivity.this, latLng, URL, KEY, activity); 
       try { 
        latLng1 = backgroundTask.execute().get(); 
       } catch (InterruptedException e) { 
        e.printStackTrace(); 
       } catch (ExecutionException e) { 
        e.printStackTrace(); 
       } 

       mMap.addMarker(new MarkerOptions().position(latLng1)); 
      } 

      @Override 
      public void onStatusChanged(String provider, int status, Bundle extras) { 
      } 

      @Override 
      public void onProviderEnabled(String provider) { 
      } 

      @Override 
      public void onProviderDisabled(String provider) { 
      } 
     }); 
    } 
} 

BackgroundTask.class

package com.example.akshay.roadsapi; 

import android.app.Activity; 
import android.content.Context; 
import android.os.AsyncTask; 
import android.util.Log; 

import com.google.android.gms.maps.model.LatLng; 

import org.apache.http.HttpEntity; 
import org.apache.http.HttpResponse; 
import org.apache.http.client.ClientProtocolException; 
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 java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.URI; 
import java.net.URISyntaxException; 

/** 
* Created by Akshay on 9/8/2015. 
*/ 
public class BackgroundTask extends AsyncTask<Void, Void, LatLng> { 
    Context CONTEXT; 
    LatLng LATLNGS; 
    String URL; 
    String KEY; 
    Double LAT = null; 
    Double LONG = null; 

    Activity ACTIVITY; 
myInt myInt = null; 
    public BackgroundTask(Context context, LatLng LATLNGS, String URL, String KEY , Activity ACTIVITY) { 
     this.CONTEXT = context; 
     this.LATLNGS = LATLNGS; 
     this.URL = URL; 
     this.KEY = KEY; 
     this.ACTIVITY = ACTIVITY; 
    } 

    @Override 
    protected LatLng doInBackground(Void... params) { 
     HttpClient client = new DefaultHttpClient(); 
     HttpGet get = new HttpGet(); 
     HttpResponse response = null; 
     HttpEntity entity = null; 
     InputStream inputStreamReader = null; 
     BufferedReader bufferedReader = null; 
     String line = null; 
     StringBuilder strin = new StringBuilder(); 

     try { 
      /*get.setURI(new URI(URL + l1.latitude + "," + l1.longitude + "|" + l2.latitude + "," + l2.longitude + "|" + l3.latitude + "," + l3.longitude + "|" + l4.latitude + "," + l4.longitude + "|" + l5.latitude + "," + l5.longitude + "|" + l6.latitude + "," + l6.longitude + "|" + 
        l7.latitude + "," + l7.longitude + "|" + l8.latitude + "," + l8.longitude + "|" + l9.latitude + "," + l9.longitude + "|" + l10.latitude + "," + l10.longitude + "|" + l11.latitude + "," + l11.longitude + "|" + l12.latitude + "," + l12.longitude + "|" + l13.latitude + "," + l13.longitude + "|" + l14.latitude + "," + l14.longitude + "|" + l15.latitude + "," + l15.longitude + "|" + l16.latitude + "," + l16.longitude + "|" + l17.latitude + "," + l17.longitude + "|" + l18.latitude + "," + l18.longitude + "|" + l19.latitude + "," + l19.longitude + "|" + l20.latitude + "," + l20.longitude + "|" + "&interpolate=false&key=" + KEY)); 
     */ 
      get.setURI(new URI(URL + LATLNGS.latitude+","+LATLNGS.longitude+"&interpolate=false&key=" + KEY)); 
      response = client.execute(get); 
      entity = response.getEntity(); 
      inputStreamReader = entity.getContent(); 
      bufferedReader = new BufferedReader(new InputStreamReader(inputStreamReader)); 
      while ((line = bufferedReader.readLine()) != null) { 
       strin.append(line + "\n"); 
      } 

      JSONObject ob = new JSONObject(strin.toString()); 
      JSONArray array = ob.getJSONArray("snappedPoints"); 
      for(int i =0 ; i<=array.length();i++) 
      { 
       JSONObject object = array.getJSONObject(i).getJSONObject("location"); 
       LAT = object.getDouble("latitude"); 
       LONG = object.getDouble("longitude"); 

      } 
     } 
     catch (URISyntaxException e) { 
      e.printStackTrace(); 
     } catch (ClientProtocolException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 

LatLng latLng = new LatLng(LAT , LONG); 
     return latLng; 

    } 

    @Override 
    protected void onPostExecute(LatLng latLng) { 
     super.onPostExecute(latLng); 
    } 
} 

Answer 1

就在這個邏輯搬進onPostExecute：

mMap.addMarker(new MarkerOptions().position(latLng1)); 

你可能會阿爾斯o需要通過AsyncTask構造函數中的GoogleMap來實現此目的。