添加标记后刷新Android谷歌地图v2

Question

我有一个应用程序，它需要android数据库中的android地图标记位置（lat/long）。我的应用中的用户也可以添加标记。问题是，当用户添加新标记的位置时，它不会显示在地图上。然而，纬度和长度值出现在MySQL数据库中，如果我重新安装应用程序，它会显示添加位置。这里的问题似乎是我必须刷新地图，我不知道如何在谷歌地图V2中做到这一点。我找到了一些答案，我应该清除所有标记，然后再加载它们像这样：

googleMap.clear(); 

但遗憾的是它没有工作。我发现，在version one有这种方法

map.invalidate(); 

可悲的是在谷歌地图v2上有没有这样的方法。有没有人有任何想法如何刷新谷歌地图v2当我重新激活活动或如果我按刷新按钮，任何建议将不胜感激。

更新 代码：

import android.annotation.SuppressLint; 
import android.app.Activity; 
import android.app.ProgressDialog; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.graphics.drawable.Drawable; 
import android.os.Build; 
import android.os.Bundle; 
import android.preference.PreferenceManager; 
import android.util.Log; 
import android.view.KeyEvent; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.RelativeLayout.LayoutParams; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.android.volley.Response; 
import com.android.volley.VolleyError; 
import com.android.volley.VolleyLog; 
import com.android.volley.toolbox.JsonArrayRequest; 
import com.google.android.gms.maps.CameraUpdate; 
import com.google.android.gms.maps.CameraUpdateFactory; 
import com.google.android.gms.maps.GoogleMap; 
import com.google.android.gms.maps.MapFragment; 
import com.google.android.gms.maps.model.BitmapDescriptorFactory; 
import com.google.android.gms.maps.model.CameraPosition; 
import com.google.android.gms.maps.model.LatLng; 
import com.google.android.gms.maps.model.Marker; 
import com.google.android.gms.maps.model.MarkerOptions; 
import com.wunderlist.slidinglayer.SlidingLayer; 

import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 

import app.AppController; 
import util.Content; 

public class MainActivity extends Activity { 


    private GoogleMap googleMap; 

    // json object response url 
    private String urlJsonObj = "alsodontneedthis.json"; 

    // json array response url 
    private String urlJsonArry = "dontneedthis"; 




    private static String TAG = MainActivity.class.getSimpleName(); 

    // Progress dialog 
    private ProgressDialog pDialog; 

    Content content = new Content(); 
    public static String valueEntered; 


    // temporary string to show the parsed response 
    private String jsonResponse; 

    private SlidingLayer mSlidingLayer; 
    private TextView swipeText; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     googleMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap(); 
     googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL); 
     googleMap.getUiSettings(); 
     googleMap.getUiSettings().setZoomControlsEnabled(true); 




     bindViews(); 
     initState(); 

     mSlidingLayer.bringToFront(); 

     redirect(); 


     googleMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() { 
      @Override 
      public boolean onMarkerClick(Marker marker) { 
       mSlidingLayer.openLayer(true); 
       return true; 
      } 
     }); 

    } 


    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.menu.menu, menu); 
     return true; 
    } 

    @SuppressLint("NewApi") 
    @Override 
    protected void onResume() { 
     super.onResume(); 

     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { 
      getActionBar().setDisplayHomeAsUpEnabled(true); 

     } 
    } 

    /** 
    * View binding 
    */ 
    private void bindViews() { 
     mSlidingLayer = (SlidingLayer) findViewById(R.id.slidingLayer1); 
//  swipeText = (TextView) findViewById(R.id.swipeText); 
    } 

    /** 
    * Initializes the origin state of the layer 
    */ 
    private void initState() { 

     SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this); 

     setupSlidingLayerPosition(prefs.getString("layer_location", "right")); 

     setupShadow(prefs.getBoolean("layer_has_shadow", false)); 
     setupLayerOffset(prefs.getBoolean("layer_has_offset", false)); 
     setupPreviewMode(prefs.getBoolean("preview_mode_enabled", false)); 
    } 

    private void setupSlidingLayerPosition(String layerPosition) { 

     LayoutParams rlp = (LayoutParams) mSlidingLayer.getLayoutParams(); 
     int textResource; 
     Drawable d; 

//  if (layerPosition.equals("right")) { 
      textResource = R.string.swipe_right_label; 
      d = getResources().getDrawable(R.drawable.container_rocket_right); 

      mSlidingLayer.setStickTo(SlidingLayer.STICK_TO_RIGHT); 


     d.setBounds(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight()); 
//  swipeText.setCompoundDrawables(null, d, null, null); 
//  swipeText.setText(getResources().getString(textResource)); 
     mSlidingLayer.setLayoutParams(rlp); 
    } 

    private void setupShadow(boolean enabled) { 
     if (enabled) { 
      mSlidingLayer.setShadowSizeRes(R.dimen.shadow_size); 
      mSlidingLayer.setShadowDrawable(R.drawable.sidebar_shadow); 
     } else { 
      mSlidingLayer.setShadowSize(0); 
      mSlidingLayer.setShadowDrawable(null); 
     } 
    } 

    private void setupLayerOffset(boolean enabled) { 
     int offsetDistance = enabled ? getResources().getDimensionPixelOffset(R.dimen.offset_distance) : 0; 
     mSlidingLayer.setOffsetDistance(offsetDistance); 
    } 

    private void setupPreviewMode(boolean enabled) { 
     int previewOffset = enabled ? getResources().getDimensionPixelOffset(R.dimen.preview_offset_distance) : -1; 
     mSlidingLayer.setPreviewOffsetDistance(previewOffset); 
    } 

    public void buttonClicked(View v) { 
     switch (v.getId()) { 
//  case R.id.buttonOpen: 
//   mSlidingLayer.openLayer(true); 
//   break; 
     case R.id.buttonClose: 
      mSlidingLayer.closeLayer(true); 
      break; 
     } 
    } 

    @Override 
    public boolean onKeyDown(int keyCode, KeyEvent event) { 
     switch (keyCode) { 
     case KeyEvent.KEYCODE_BACK: 
      if (mSlidingLayer.isOpened()) { 
       mSlidingLayer.closeLayer(true); 
       return true; 
      } 

     default: 
      return super.onKeyDown(keyCode, event); 
     } 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
      case R.id.addNewEvent: 

       Intent intent = new Intent(this, AddEvent.class); 
       startActivity(intent); 
       ; 
     } 

     return true; 
    } 







    private void redirect() { 


     //showpDialog(); 

     JsonArrayRequest req = new JsonArrayRequest(urlJsonArry, 
       new Response.Listener<JSONArray>() { 
        @Override 
        public void onResponse(JSONArray response) { 
         Log.d(TAG, response.toString()); 


         try { 
          Content content = new Content(); 
          // Parsing json array response 
          // loop through each json object 
          jsonResponse = ""; 
          for (int i = 0; i < response.length(); i++) { 

           JSONObject person = (JSONObject) response 
             .get(i); 

           String name = person.getString("nosaukums"); 
           String email = person.getString("nosaukums"); 
           String relation = person.getString("nosaukums"); 

           Double lat=person.getDouble("latCo"); 
           Double lng=person.getDouble("longCo"); 


           content.setName(name); 

           content.setPopulation(email); 
           content.setlat(lat); 
           content.setlng(lng); 
           content.setRelation(relation); 
           System.out.println("name="+content.getName()+content.getlat()); 
           LatLng lt = new LatLng(content.getlat(), content.getlng()); 
           content.setLatlng(lt); 
           //valueEntered=lt.toString(); 
           System.out.println("address="+content.getLatlng()); 
             /*String home = latlng.getLong("home"); 
             String mobile = phone.getString("mobile");*/ 
           System.out.println("relation="+content.getRelation()); 

           jsonResponse += "Name: " + name + "\n\n"; 
           jsonResponse += "Population: " + email + "\n\n"; 
           jsonResponse += "Latitude: " + lat + "\n\n"; 
           jsonResponse += "Longitude: " + lng + "\n\n\n"; 
           jsonResponse += "Relation" + relation +"\n\n\n"; 

           if(content.getRelation().equals("son")) 
           { 
            googleMap.addMarker(new MarkerOptions() 
              .position(lt) 
              .icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_son)) 
              .snippet(email) 
              .title(content.getName())).showInfoWindow(); 

           } 
           else 
           { 
            googleMap.addMarker(new MarkerOptions() 
              .position(lt) 
              .icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_daughter)) 

              .title(content.getName())).showInfoWindow(); 

           } 

           CameraPosition cameraPosition = new CameraPosition.Builder().target(lt).zoom(15.0f).build(); 
           CameraUpdate cameraUpdate = CameraUpdateFactory.newCameraPosition(cameraPosition); 
           googleMap.moveCamera(cameraUpdate); 



          } 



          //txtResponse.setText(jsonResponse); 

         } catch (JSONException e) { 
          e.printStackTrace(); 
          Toast.makeText(getApplicationContext(), 
            "Error: " + e.getMessage(), 
            Toast.LENGTH_LONG).show(); 
         } 

         //hidepDialog(); 


        } 
       }, new Response.ErrorListener() { 
      @Override 
      public void onErrorResponse(VolleyError error) { 
       VolleyLog.d(TAG, "Error: " + error.getMessage()); 
       Toast.makeText(getApplicationContext(), 
         error.getMessage(), Toast.LENGTH_SHORT).show(); 
       //hidepDialog(); 
      } 
     }); 

     // Adding request to request queue 
     //AppController.getInstance() == null; 
     AppController.getInstance().addToRequestQueue(req); 
    } 

} 

Answer 1

由于googleMap.appMarker()似乎没有被调用，在调用content.getRelation().equals("son")时propaply捕捉异常。