Question

好的我已经尝试了Nicholas的解决方案，但是如果我按下后退按钮，当应用程序搜索gps fix.so我上传所有代码和文件（除了icon.png和pen.png在drawables中）时，仍然会强行关闭project ...这样就可以从这里复制粘贴代码以查看最新情况。我的main.xml：

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/icon"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<Button android:text="Start" 
android:id="@+id/Button01" 
android:layout_width="120px" 
android:layout_height="70px"
android:layout_gravity = "center_horizontal"
android:textSize="20px"
android:layout_marginTop="150px"
android:clickable="true"
></Button>

</LinearLayout>

接下来我的主要活动（GpsLocEx.java）

package com.example.gpslocex;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class GpsLocEx extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button start = (Button) findViewById(R.id.Button01);
        start.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
             Intent map = new Intent(view.getContext(), com.example.gpslocex.ShowMap.class);
             startActivityForResult(map, 0);

            }

        });


 }
    }

下一个我的gps.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/mainlayout"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <com.google.android.maps.MapView
        android:id="@+id/mapview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:clickable="true"
        android:apiKey="06ZLf-HkdkRMb513KS2ZRljmMQL0bntlyMJ-rOQ"
    />

</RelativeLayout>

下一个ShowMap.java

package com.example.gpslocex;

import java.util.List;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Point;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;

public class ShowMap extends MapActivity {

    private MapController mapController;
    private MapView mapView;
    private LocationManager locationManager;
    private GeoUpdateHandler geoUpdateHandler;

    @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.gps);
            mapView = (MapView) findViewById(R.id.mapview);
            mapView.setBuiltInZoomControls(true);
            mapView.setSatellite(true);
            mapController = mapView.getController();
            mapController.setZoom(14); // Zoom 1 is world view
            geoUpdateHandler = new GeoUpdateHandler();

            locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
            if (!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
                createGpsDisabledAlert();
            } else {
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0,
                        0,geoUpdateHandler);

            }

       }
     private void createGpsDisabledAlert() {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder
                    .setMessage(
                            "Your GPS is disabled! Would you like to enable it?")
                    .setCancelable(false).setPositiveButton("Enable GPS",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    showGpsOptions();
                                }
                            });
            builder.setNegativeButton("Do nothing",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            dialog.cancel();
                        }
                    });
            AlertDialog alert = builder.create();
            alert.show();
        }

     private void showGpsOptions() {
            Intent gpsOptionsIntent = new Intent(
                    android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            startActivity(gpsOptionsIntent);
        } 


     @Override
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }


    public class GeoUpdateHandler implements LocationListener {

        @Override
        public void onLocationChanged(Location location) {
            int lat = (int) (location.getLatitude() * 1E6);
            int lng = (int) (location.getLongitude() * 1E6);
            GeoPoint point = new GeoPoint(lat, lng);
            mapController.animateTo(point); //  mapController.setCenter(point);
             MapOverlay mapOverlay = new MapOverlay();
              mapOverlay.setPointToDraw(point);
              List<Overlay> listOfOverlays = mapView.getOverlays();
              listOfOverlays.clear();
              listOfOverlays.add(mapOverlay);

        }

        @Override
        public void onProviderDisabled(String provider) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onProviderEnabled(String provider) {
        }

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


    class MapOverlay extends Overlay
    {
      private GeoPoint pointToDraw;

      public void setPointToDraw(GeoPoint point) {
        pointToDraw = point;
      }

      public GeoPoint getPointToDraw() {
        return pointToDraw;
      }

      @Override
      public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) {
        super.draw(canvas, mapView, shadow);           

        // convert point to pixels
        Point screenPts = new Point();
        mapView.getProjection().toPixels(pointToDraw, screenPts);

        // add marker
        Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.pen);
        canvas.drawBitmap(bmp, screenPts.x, screenPts.y - 128, null);    
        return true;
      }




    }
    @Override
    public void onPause() {
        locationManager.removeUpdates(geoUpdateHandler);
    }


}

next strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Version-1.0</string>
    <string name="app_name">GpsLocEx</string>

</resources>

最后是AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.example.gpslocex"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <uses-library android:name="com.google.android.maps" />
        <activity android:name=".GpsLocEx"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
<activity android:name=".ShowMap"></activity>

</application>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="ACCESS_COARSE_LOCATION" />

</manifest>

Answer 1

当Activity不再位于顶部时，您可以使用Android lifecycle methods关闭GPS。

使用onPause（），onStop（）或onDestroy（）从locationManager中删除更新。像这样：

@Override
public void onPause() {
    locationManager.removeUpdates(myLocationListener);
}

编辑：

您的onPause()方法中存在ClassCastException。您无法将this（您的Activity）投射到LocationListener（至少在没有制作Activity工具LocationListener的情况下）。

在您的代码中，您创建了一个new GeoUpdateHandler()。首先，您应该创建一个作为GeoUpdateHandler的instanceVariable。在LocationManager的实例变量下方，创建一个如下：

private GeoUpdateHandler geoUpdateHandler;

你应该在onCreate（）方法中保留一个句柄：

@Override
public void onCreate(Bundle savedInstanceState) {
    //...some code here...
    geoUpdateHandler = new GeoUpdateHandler();
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0,
                        0,geoUpdateHandler);
    //...maybe some more code here...
}

然后在onPause中，将geoUpdateHandler传递给removeUpdates函数：

@Override
public void onPause() {
    locationManager.removeUpdates(geoUpdateHandler);
}

编辑2：

stacktrace说明了一切：

android.app.SuperNotCalledException: Activity {com.example.gpslocnav6ex/com.example.gpslocnav6ex.ShowMap} did not call through to super.onPause()

在onPause（）

中调用super.onPause（）

@Override
public void onPause() {
    super.onPause();
    locationManager.removeUpdates(geoUpdateHandler);
}

Answer 2

试试这个locationManager.removeUpdates(myLocationListener);

你应该在onPause（）

中写下来

@Override
    protected void onPause()
    {
        // TODO Auto-generated method stub
        super.onPause();
                locationManager.removeUpdates(myLocationListener);
    }

退出应用程序时，这将关闭GPS。

在退出应用程序时停止gps

2 个答案: