我在這裏有一個問題,我不能得到它的工作... 我想獲得最新的GPS位置,但我得到的是空指針異常。 它適用於第一類GPSActivity,但不適用於第二個SmsReceiver。Android locationManager空指針異常? (如何通過上下文?)
我讀到這可能是因爲我必須將上下文傳遞給第二類,但我不知道如何......請幫助!
這裏談到的代碼:
GPSActivity.class
:
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
public class GPSActivity extends Activity {
long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
long MINIMUM_TIME_BETWEEN_UPDATES = 10000; // in Milliseconds
LocationManager locationManager;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
locationManager =
(LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.getAllProviders();
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MINIMUM_TIME_BETWEEN_UPDATES,
MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
new MyLocationListener());
}
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(GPSActivity.this, message,
Toast.LENGTH_LONG).show();
}
}
}
(我扯下了代碼位)
現在,我可以打電話showCurrentLocation並showes我長和緯度值。
我怎麼能做到這一點的位置:
SmsReceive.class
(收到短信時,發送的GPS座標)
import ...
public class SmsReceiver extends BroadcastReceiver
{
@Override
public void onReceive(Context context, Intent intent)
{
GPSActivity myGPS;
myGPS = new GPSActivity();
//---get the SMS message passed in---
Bundle bundle = intent.getExtras();
SmsMessage[] msgs = null;
if (bundle != null) {
//HERE I GET THE NULL POINTER EXCEPTION
Location loc =
myGPS.locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
double varLong = loc.getLongitude();
double varLat = loc.getLatitude();
String locationData = "LONG: " + varLong+ " LAT: " + varLat;
Toast.makeText(context, locationData, Toast.LENGTH_SHORT).show();
}
}
}
的感謝!