Question

您正在使用简单的Android应用程序，显示用户的地址，但这个应用程序正在模拟器中工作，但当我在移动设备安装它显示力close.please帮助我提前感谢

 package com.gps.com;
    import java.io.IOException;
    import java.util.List;
import java.util.Locale;
import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class main extends Activity {

    private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
    private static final long MINIMUM_TIME_BETWEEN_UPDATES = 1000; // in Milliseconds

    protected LocationManager locationManager;

    protected Button retrieveLocationButton;
    public Location location;
    public TextView tv;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);
         tv= (TextView)findViewById(R.id.tv);
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        locationManager.requestLocationUpdates(
                LocationManager.GPS_PROVIDER, 
                MINIMUM_TIME_BETWEEN_UPDATES, 
                MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
                new MyLocationListener()
        );
        retrieveLocationButton.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                showCurrentLocation();

            }
        });


    }    

    public void showCurrentLocation() {

        Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

        if (location != null) {
            String message = String.format(
                    "Current Location \n Longitude: %1$s \n Latitude: %2$s",
                    location.getLongitude(), location.getLatitude()
            );
            Toast.makeText(main.this, message,
                    Toast.LENGTH_LONG).show();
        }
        try {
            List<Address> addresses;

            Geocoder gc = new Geocoder(this, Locale.ENGLISH); 
            addresses = gc.getFromLocation(location.getLatitude(),location.getLongitude(), 1); 
            if(addresses != null) {
            Address currentAddr = addresses.get(0);
            StringBuilder sb = new StringBuilder("Address:\n"); 
            for(int i=0; i<currentAddr.getMaxAddressLineIndex(); i++) {
            sb.append(currentAddr.getAddressLine(i)).append("\n"); 
            }
            tv.setText(sb.toString()); 
            }
            } catch(IOException e) { 
            tv.setText("Something is mistake the error is"+e);
            }

    }   

    private class MyLocationListener implements LocationListener {

        public void onLocationChanged(Location location) {
            String message = String.format(
                    "New Location \n Longitude: %1$s \n Latitude: %2$s",
                    location.getLongitude(), location.getLatitude()
            );
            Toast.makeText(main.this, message, Toast.LENGTH_LONG).show();
        }

        public void onStatusChanged(String s, int i, Bundle b) {
            Toast.makeText(main.this, "Provider status changed",
                    Toast.LENGTH_LONG).show();
        }

        public void onProviderDisabled(String s) {
            Toast.makeText(main.this,
                    "Provider disabled by the user. GPS turned off",
                    Toast.LENGTH_LONG).show();
        }

        public void onProviderEnabled(String s) {
            Toast.makeText(main.this,
                    "Provider enabled by the user. GPS turned on",
                    Toast.LENGTH_LONG).show();
        }

    }


}

Answer 1

这一行

addresses = gc.getFromLocation(location.getLatitude(),location.getLongitude(), 1);

可能会给你一个Nullpointer异常，因为它在if-block之外，是未处理的，因为你只是在特定的try-block中捕获IOException。这可能不是解决你遇到的问题的方法，但我认为无论如何我都会指出它。

Answer 2

这也是一个明显的建议，但你不能以编程方式打开GPS，你必须手动完成。您是否已确认手机中的GPS已开启？

Answer 3

我也有同样的问题。在manifest.xml中尝试此代码。它为我工作。

MainActivity：

public class WhereIActivity extends MapActivity {


      // MapController mc;
       MapView myMapView;
       MapController mapController;
       GeoPoint point;
       MyPositionOverlay positionOverlay;



    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_where_i);

        MapView myMapView=(MapView)findViewById(R.id.myMapView);

        mapController=myMapView.getController();


       myMapView.displayZoomControls(false);

       mapController.setZoom(17);

       positionOverlay=new MyPositionOverlay();
       List<Overlay> overlays=myMapView.getOverlays();
       overlays.add(positionOverlay);

      // myMapView.setSatellite(true);

       myMapView.setStreetView(true);
       myMapView.setTraffic(true);





        LocationManager locationManager; 
        String context = Context.LOCATION_SERVICE; 
        locationManager = (LocationManager)getSystemService(context); 

        Criteria crta = new Criteria(); 
        crta.setAccuracy(Criteria.ACCURACY_FINE); 
        crta.setAltitudeRequired(false); 
        crta.setBearingRequired(false); 
        crta.setCostAllowed(true); 
        crta.setPowerRequirement(Criteria.POWER_LOW); 
        String provider = locationManager.getBestProvider(crta, true); 

     // String provider = LocationManager.GPS_PROVIDER; 
        Location location = locationManager.getLastKnownLocation(provider); 
        updateWithNewLocation(location); 

        locationManager.requestLocationUpdates(provider, 2000, 10, locationListener); 
        } 
    private final LocationListener locationListener = new LocationListener() 
    { 

    @Override 
    public void onLocationChanged(Location location) { 
    updateWithNewLocation(location); 
    } 

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

    @Override 
    public void onProviderEnabled(String provider) { 
    } 

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

    }; 

    private void updateWithNewLocation(Location location) { 
        String latLong;
        TextView myLocation; 
        myLocation = (TextView) findViewById(R.id.myLocation); 

        String addressString = "no address found"; 

        if(location!=null) { 



            positionOverlay.setLocation(location);


            Double geoLat=location.getLatitude()*1E6;
            Double geoLng=location.getLongitude()*1E6;
            GeoPoint point=new GeoPoint(geoLat.intValue(),geoLng.intValue());

            mapController.animateTo(point);

        double lat = location.getLatitude(); 
        double lon = location.getLongitude(); 
        latLong = "Lat:" + lat + "\nLong:" + lon; 



        double lattitude = location.getLatitude(); 
        double longitude = location.getLongitude(); 

        Geocoder gc = new Geocoder(this,Locale.getDefault()); 
        try { 
        List<Address> addresses= gc.getFromLocation(lattitude, longitude, 1); 
        StringBuilder sb = new StringBuilder(); 
        if(addresses.size()>0) { 
        Address address=addresses.get(0);
        for(int i=0;i<address.getMaxAddressLineIndex();i++)
            sb.append(address.getAddressLine(i)).append("\n");
        sb.append(address.getLocality()).append("\n"); 
        sb.append(address.getPostalCode()).append("\n"); 
    sb.append(address.getCountryName()); 
    } 
        addressString = sb.toString(); 
        } 
        catch (Exception e) { 
        } 
        } else { 
        latLong = " NO Location Found "; 
        } 

        myLocation.setText("Current Position is :\n"+ latLong + "\n"+  addressString ); 
           }

MyPositionOverlay：

public class MyPositionOverlay extends Overlay {

    Location location;
    private final int mRadius=5;

    @Override
    public void draw(Canvas canvas,MapView mapView,boolean shadow){

        Projection projection=mapView.getProjection();

        if(shadow==false){
            Double latitude=location.getLatitude()*1E6;
            Double longitude=location.getLongitude()*1E6;

            GeoPoint geoPoint;
             geoPoint=new GeoPoint(latitude.intValue(),longitude.intValue());

             Point point=new Point();
             projection.toPixels(geoPoint, point);

             RectF oval=new RectF(point.x - mRadius,point.y - mRadius,point.x + mRadius,point.y + mRadius);

             Paint paint=new Paint();
             paint.setARGB(250, 255, 255, 255);

             paint.setAntiAlias(true);
             paint.setFakeBoldText(true);

             Paint backPaint=new Paint();
             backPaint.setARGB(175, 50, 50, 50);
             backPaint.setAntiAlias(true);

             RectF backRect=new RectF(point.x + 2 + mRadius, point.y - 3*mRadius,point.x + 65, point.y + mRadius);

             canvas.drawOval(oval, paint);
             canvas.drawRoundRect(backRect, 5, 5, backPaint);
             canvas.drawText("Here I Am", point.x + 2*mRadius, point.y, paint);
        }
        super.draw(canvas, mapView, shadow);


        }

    @Override
    public boolean onTap(GeoPoint point,MapView mapView){


            return false;
            }


public Location getLocation(){

    return location;

}
public void setLocation(Location location){
    this.location=location;
}
}

main.xml中：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    tools:context=".WhereIActivity" >

    <com.google.android.maps.MapView
        android:id="@+id/myMapView"
                 android:layout_width="fill_parent"
                 android:layout_height="fill_parent"
                 android:enabled="true"
                 android:clickable="true"                
                  android:apiKey="0_MW1zfGUXAZ2cAEBaB62GeWv0FoZODowBf1WYg"
          />

    <TextView
        android:id="@+id/myLocation"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"

        tools:context=".WhereIActivity"

        android:gravity="center_horizontal"

         android:textStyle="bold"
        android:textSize="14sp"
        android:typeface="sans"
        android:textColor="#0099CC"

                 android:layout_alignParentTop="true"     

         />    

</RelativeLayout>

manifest.xml：

    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.android.wherei"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="4"
        android:targetSdkVersion="15" />


    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <uses-library android:name="com.google.android.maps"></uses-library>      
          <activity
            android:name=".WhereIActivity"
            android:label="@string/title_activity_where_i" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />       
<uses-permission android:name="android.permission.INTERNET" />     
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
</manifest>

gps在模拟器中工作但不在移动设备上工作

3 个答案: