单击按钮时不显示GPS位置

时间:2017-07-04 16:49:32

标签: android android-location android-gps

我试图通过点击按钮获取gps location。 代码如下:

MainActivity.java

public class MainActivity extends AppCompatActivity {

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;

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

    retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);

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

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        if (Build.VERSION.SDK_INT >= 23) { // Marshmallow

            ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 1252);
        }
        return;

    }

    locationManager.requestLocationUpdates(
            LocationManager.GPS_PROVIDER,
            MINIMUM_TIME_BETWEEN_UPDATES,
            MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
            new MyLocationListener()
    );

    retrieveLocationButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            showCurrentLocation();
        }
    });

}

protected void showCurrentLocation() {

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        if (Build.VERSION.SDK_INT >= 23) { // Marshmallow

            ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 1252);
        }
        return;
    }
    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(MainActivity.this, message,
                Toast.LENGTH_LONG).show();
    }

}

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(MainActivity.this, message, Toast.LENGTH_LONG).show();
    }

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

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

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

}

}

此处的问题是Toast未显示在显示位置即latitudelongitude的位置。我为runtime permission添加了API level 23。我还在manifest文件中添加了以下权限:

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

感谢您的帮助:)

1 个答案:

答案 0 :(得分:0)

我通过在onRequestPermissionsResult..类之上添加MyLocationListener来解决它。以下代码是更正后的代码:

<强> MainActivity.java

公共类MainActivity扩展了AppCompatActivity {

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;

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

    retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);

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

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        if (Build.VERSION.SDK_INT >= 23) { // Marshmallow

            ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 1252);
        }
        return;

    }

    locationManager.requestLocationUpdates(
            LocationManager.GPS_PROVIDER,
            MINIMUM_TIME_BETWEEN_UPDATES,
            MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
            new MyLocationListener()
    );

    retrieveLocationButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            showCurrentLocation();
        }
    });

}

protected void showCurrentLocation() {

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        if (Build.VERSION.SDK_INT >= 23) { // Marshmallow

            ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 1252);
        }
        return;
    }
    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(MainActivity.this, message,
                Toast.LENGTH_LONG).show();
    }

}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode==1252){
        if (grantResults.length>0 && grantResults[0]==PackageManager.PERMISSION_GRANTED){
            Log.i("Permission Granted : ", String.valueOf(grantResults));

        }
    }
}

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(MainActivity.this, message, Toast.LENGTH_LONG).show();
    }

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

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

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

}

}

谢谢@Pavneet_Singh