我正在申请，我们是否在房间内。我必须存储4个角值意味着做多边形。但是我无法在同一个位置获得准确的价值，它在同一个位置获得不同的价值。如何解决这个问题??
代码：
MainActivity.java
public class MainActivity extends Activity {
Button btnShowLocation;
TextView tvLat;
TextView tvLang;
TextView tvInsideRoom;
dbHandler myDbHelper;
// GPSTracker class
GPSTracker gps;
Handler mHandler1;
tvInsideRoom = (TextView)findViewById(R.id.insideRoom);
btnShow = (Button) findViewById(R.id.btnShow);
// show location button click event
btnShow.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
mHandler1 = new Handler();
new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
while (true) {
try {
Thread.sleep(100);
mHandler1.post(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
// creating GPS Class object
GPSTracker gps = new GPSTracker (MainActivity.this);
// check if GPS location have some values
if (gps.canGetLocation()) {
double currentlat = gps.getLatitude();
double currentlong = gps.getLongitude();
tvLat = (TextView)findViewById(R.id.lat);
tvLang = (TextView)findViewById(R.id.lang);
tvLat.setText(""+currentlat);
tvLang.setText(""+currentlong);
boolean boolFlag = myDbHelper.isInsideRoom(currentlat,currentlong);
tvInsideRoom.setText("");
if(boolFlag)
tvInsideRoom.setText("You are in inside Room");
else
tvInsideRoom.setText(""+boolFlag);
} else {
// no current location
gps.showSettingsAlert();
}
}
});
} catch (Exception e) {
// TODO: handle exception
}
}
}
}).start();
}
}); }
GPSTracker.java
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 = 1; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 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) {
Log.d("Accuracy1 := ", ""+location.getAccuracy());
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) {
Log.d("Accuracy2 := ", ""+location.getAccuracy());
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) {
this.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;
}}
答案 0 :(得分：3)
位置跟踪的准确性可能差异很大。由于准确度不足，您要实现的目标永远不会奏效。特别是在房间内，但即使有GPS。
根据您所处的位置，网络小区塔，wifi或GPS将用于确定当前位置，并且所有位置都具有不同的准确度。即使在室外，通常需要几秒钟才能获得GPS定位。
使用getAccuracy()检查您的位置是否对当前修复程序有用。