我有这个代码，我想从GPSTracker类获取gps纬度和经度
但错误显示
gps=new GPSTracker(MainActivity.this);
gps.getLatitude();
在作用域中不能访问mainActivity类型的封闭实例
完整的代码
bootcomplete.java文件
public class BootComplete extends BroadcastReceiver{
//private static final String PREFS_NAME = null;
public static final String PREFS_NAME = "MyPrefs";
String storedSimSerial;
String currentSimSerial;
String email; //email address input by user, generate email and sent to this address
String mobileno; //mobile number input by user, generate SMS and send to this address
String sms; //generate sms to user
public GPSTracker gps;
@Override
public void onReceive(final Context context, Intent intent) {
SharedPreferences prefs = context.getSharedPreferences(PREFS_NAME, 0);
storedSimSerial = prefs.getString("storedSimSerial", "");
mobileno = prefs.getString("trustedNum", "");
email = prefs.getString("Email", "");
TelephonyManager tm = (TelephonyManager) context.getSystemService(Service.TELEPHONY_SERVICE);
currentSimSerial = tm.getSimSerialNumber();
if(currentSimSerial != null){
if(currentSimSerial.compareToIgnoreCase(storedSimSerial) == 0){
}else{
prefs = context.getApplicationContext().getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = prefs.edit();
gps=new GPSTracker(MainActivity.this);
gps.getLatitude();
sms = "Alert!!!\nSim card changed.\nSim Serial Number:\n"+tm.getSimSerialNumber()+
"\nNetwork : "+ tm.getNetworkOperatorName()+"\nLatitude:\n" + gps.getLatitude();
editor.putBoolean("SimChangeMail", true);
editor.putString("subjectSimChange", "Your Sim card has changed.");
editor.putString("bodySimChange","Sim Serial Number is :\n"+tm.getSimSerialNumber()+"\n" +
"This Sim serial number is unique and used to identify the owner.\nNetwork Operator is : "+
tm.getNetworkOperatorName()+
"\nThanks for using Mobile Security Application");
editor.putString("SimChangeSms", sms);
editor.commit();
SmsManager sm = SmsManager.getDefault();
String num = mobileno;
sm.sendTextMessage(num, null, sms, null, null);
}
}else{
}
}
}
gpstracker.java语言
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
this.canGetLocation = true;
// First get location from Network Provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
}
最佳答案
如果bootcomplete是mainActivity中的嵌套类，则只能使用MainActivity.this。
因为你的gpstracker只需要一个上下文，你可以
gps = new GPSTracker(context);
关于java - 在作用域中无法访问类型为MainActivity的封闭实例，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/15390139/