新的权限系统（位置整合）

Question

这是我的第一个问题。我学习计算机科学，并试图提高我在android开发方面的技能。所以我想制作一个简单的天气应用程序。我不习惯android 6.0的新权限系统，所以我需要你的帮助。

我总是有问题，日志告诉我，没有找到位置（我使用的字符串，如果位置为空）。我这样做，因为我想要检查是否有任何位置。之后，我想将纬度和高度传递给用于请求坐标的天气数据的API。请看看我的代码，并试图帮助我，给我一些建议，以提高代码：

public class MainActivity extends AppCompatActivity implements LocationListener { 

LocationManager locationManager; 
Location location; 
String provider; 
String[] permissions = {Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}; 

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

    //LocationManager Setup get System Services 
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
    provider = locationManager.getBestProvider(new Criteria(), false); 

    //Get Last known Location 
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && 
      ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 

     ActivityCompat.requestPermissions(this, permissions, 10); 

    } else { 

     locationManager.requestLocationUpdates(provider, 400, 1000, this); 
     location = locationManager.getLastKnownLocation(provider); 

     if (location != null) { 
      Log.i("Location Info", "Location Achieved"); 
     } else { 
      Log.i("Location Info", "No Location found"); 
     } 
    } 
} 

@Override 
protected void onResume() { 
    super.onResume(); 
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 
     ActivityCompat.requestPermissions(this, permissions, 10); 
     return; 
    } else { 
     locationManager.requestLocationUpdates(provider, 400, 1000, this); 
    } 
} 

@Override 
protected void onPause() { 
    super.onPause(); 
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 
     ActivityCompat.requestPermissions(this, permissions, 10); 
     return; 
    } else { 
     locationManager.removeUpdates(this); 
    } 
} 



@Override 
public void onLocationChanged(Location location) { 
    Double lat = location.getLatitude(); 
    Double lng = location.getLongitude(); 

    Log.i("Latitude", lat.toString()); 
    Log.i("Longitude", lng.toString()); 
} 

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

} 

@Override 
public void onProviderEnabled(String provider) { 

} 

@Override 
public void onProviderDisabled(String provider) { 

} 
} 

Answer 1

你需要处理Permissions Result

@Override 
public void onRequestPermissionsResult(int requestCode, 
    String permissions[], int[] grantResults) { 
switch (requestCode) { 
    case MY_PERMISSIONS_REQUEST_LOCATION: { // for your case 10 
     // If request is cancelled, the result arrays are empty. 
     if (grantResults.length > 0 
      && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 

      // permission was granted, yay! Do the 
      // location-related task you need to do. 

     } else { 

      // permission denied, boo! Disable the 
      // functionality that depends on this permission. 
     } 
     return; 
    } 

    // other 'case' lines to check for other 
    // permissions this app might request 
} 
}