我想在 Android 屏幕上更新位置数据。我在LiczydloGPS.class中有 LocationListener 和 LocationManager :
package com.zoltrix.gpsallinfo;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;
public class LiczydloGPS extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
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 LiczydloGPS(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;
}
@Override
public void onLocationChanged(Location location) {
if(location!=null)
{
MainActivity main2 = new MainActivity();
main2.update(location.getLatitude(), location.getLongitude());
}
Log.d("onLocationChanged", "idze do maina");
}
@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;
}
/**
* 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 if best network provider
*
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* */
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?");
// Setting Icon to Dialog
// alertDialog.setIcon(R.drawable.delete);
// 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();
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(LiczydloGPS.this);
}
}
}
在 MainActivity 我进行了方法更新,该方法在onLocationChanged的 LiczydloGPS.class中调用:
package com.zoltrix.gpsallinfo;
import com.zoltrix.gpsallinfo.R.id;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
double lat, lon;
TextView latData, longData;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
latData = (TextView) findViewById(R.id.latData);
longData = (TextView) findViewById(R.id.longData);
LiczydloGPS gps = new LiczydloGPS(this);
if (gps.canGetLocation() != true) {
gps.showSettingsAlert();
} else {
lat = gps.getLatitude(); // returns latitude
lon = gps.getLongitude();
latData.setText(String.valueOf(lat));
longData.setText(String.valueOf(lon));
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// TODO Auto-generated method stub
switch (item.getItemId()) {
case id.oprogramie:
Intent intent = new Intent(this, Oprogramie.class);
startActivity(intent);
case id.action_settings:
Intent intent2 = new Intent(this, Ustawienia.class);
startActivity(intent2);
}
return super.onOptionsItemSelected(item);
}
public void update(double lat1, double lon1) {
Log.d("onLocationChanged", "jest w mainie!");
latData.setText(lat1);
longData.setText(lon1);
Log.d("onLocationChanged", String.valueOf(lat1));
//Toast.makeText(getApplicationContext(), "TOAST!!!!!!!!!!!!!!!", Toast.LENGTH_SHORT).show();
}
}
但是当您想更改 DDMS 中的 GPS 数据时,该应用程序将被终止。日志:
11-11 09:22:27.626:D/GPS 已启用 (2734):GPS 已启用 11-11 09:22:28.136:D/gralloc_goldfish(2734):没有检测到 GPU 仿真的模拟器。11-11 09:22:32.506: D/onLocationChanged(2734): 开个玩笑!11-11 09:22:32.506: D/AndroidRuntime(2734): 关闭 VM 11-11 09:22:32.506: W/dalvikvm(2734): threadid=1: 线程以未捕获的异常退出 (group=0xb3aa2b90) 11 -11 09:22:32.516:E/AndroidRuntime(2734):致命异常:主要 11-11 09:22:32.516:E/AndroidRuntime(2734):进程:com.zoltrix.gpsallinfo,PID:2734 11-11 09 :22:32.516: E/AndroidRuntime(2734): java.lang.NullPointerException 11-11 09:22:32.516: E/AndroidRuntime(2734): at com.zoltrix.gpsallinfo.MainActivity.update(MainActivity.java:69) 11-11 09:22:32.516: E/AndroidRuntime(2734): 在 com.zoltrix.gpsallinfo.LiczydloGPS.onLocationChanged(LiczydloGPS.java:
在此先感谢您的帮助