谷歌地图api v2闪烁

Question

我的地图代码似乎会导致我的应用程序每秒钟闪烁一次。有人看到突出的东西吗？它用红圈追踪我去过的地方。它似乎也没有达到我设置的缩放级别。

感谢

 package com.direction.investor.farmsprayer;
import com.direction.investor.farmsprayer.R;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.LocationSource.OnLocationChangedListener;

import com.google.android.gms.maps.model.Circle;
 import com.google.android.gms.maps.model.CircleOptions;
 import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.PolygonOptions;
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
import com.google.android.gms.maps.*;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.graphics.Color;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.location.LocationListener;
public class MainActivity extends Activity implements LocationListener{
Location myLocation;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


// Get back the mutable Circle
Location myLocation;
LocationManager locationmanager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria cr = new Criteria();
String provider = locationmanager.getBestProvider(cr, true);
Location location = locationmanager.getLastKnownLocation(provider);
locationmanager.requestLocationUpdates(provider, 200, 0, (LocationListener) this);

}
@SuppressLint("NewApi")
@Override
public void onLocationChanged(Location location) {
    // TODO Auto-generated method stub
     GoogleMap mMap;
        mMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
        mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);

        mMap.setMyLocationEnabled(true);
        mMap.animateCamera(CameraUpdateFactory.zoomBy(17));
     mMap.moveCamera(CameraUpdateFactory.newLatLng((new LatLng(location.getLatitude(), location.getLongitude()))));

     CircleOptions circleOptions = new CircleOptions()
    .center(new LatLng(location.getLatitude(), location.getLongitude()));
    circleOptions.radius(3.048); // In meters
    circleOptions.fillColor(0xffff0000);
    circleOptions.strokeWidth(0);

     mMap.addCircle(circleOptions); 

}

Answer 1

在当前代码中，每次调用onlocationchanged方法时都要重新初始化映射片段。

将映射GoogleMap mMap;标记为类中所有方法都可以访问的全局变量。每当你的应用程序加载时，只初始化你的地图片段一次，所以把下面的代码移到你的onResume()方法中，这样它只调用一次。同样，在将mMap设置为映射片段后，在进行其他映射初始化之前，进行null检查以确保片段已加载。

     mMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
        if(mMap!=null) {
                mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
                mMap.setMyLocationEnabled(true);
                mMap.animateCamera(CameraUpdateFactory.zoomBy(17));
}