Question

我正在创建一个使用设备当前位置的Android应用。为了做到这一点，我使用以下代码开发了一个应用程序，每5秒获取一次当前位置。

import android.*;
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.media.audiofx.BassBoost;
import android.os.Build;
import android.provider.Settings;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class CurrentLocation extends AppCompatActivity {

    private Button button;
    private TextView textView;

    private LocationManager locationManager;
    private LocationListener locationListener;

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

        button = (Button) findViewById(R.id.button);
        textView = (TextView) findViewById(R.id.textView);

        locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                textView.append("\n " + location.getLongitude() + " " + location.getLatitude());
            }

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

            }

            @Override
            public void onProviderEnabled(String provider) {

            }

            @Override
            public void onProviderDisabled(String provider) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                startActivity(intent);
            }
        };

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                requestPermissions(new String[]{
                        Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION,
                        Manifest.permission.INTERNET
                }, 10);
                return;
            }
        }
        else{
            configureButton();
        }
        ;
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 10:
                if(grantResults.length>0 && grantResults[0]==PackageManager.PERMISSION_GRANTED)
                    configureButton();
        }
    }

    private void configureButton() {
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                locationManager.requestLocationUpdates("gps", 5000, 0, locationListener);
            }
        });

    }
}

第一次在我的设备中安装此应用程序时，它运行得非常好。但在那之后它根本不起作用。它甚至没有要求打开位置服务。有人可以帮我这个。谢谢。

Answer 1

在locationManager.requestLocationUpdates("gps", 5000, 0, locationListener);之前，您应该检查GPS（位置服务）是否已开启。你可以用以下功能来做到这一点：

public boolean isGPSOn() {
    boolean isOn = ((LocationManager) this.getSystemService(Context.LOCATION_SERVICE))
            .isProviderEnabled(LocationManager.GPS_PROVIDER);
    if (!isOn) {
        showGPSEnableDialog();
    }
    return isOn;
}

如果不工作，可以显示对话框或直接重定向到设置以启用它。对话更好。如果用户选择在对话框中启用GPS，则会重定向到此类设置。

startActivity(new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));

Android位置应用程序

1 个答案: