我是安卓新手.我目前正在开发一个 android 项目,我需要使用 GPS 获取用户的当前位置.但是我的代码不能正常工作.
I'm new in android. I'm currently working on an android project in witch I need to get user's current location using GPS. But my code is not working properly.
java代码
package com.example.checkinapp;
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.widget.TextView;
public class MainActivity extends Activity
{
TextView textlat;
TextView textlong;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textlat = (TextView)findViewById(R.id.textlat);
textlong = (TextView)findViewById(R.id.textlong);
LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener ll = new mylocationlistener();
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, ll);
}
class mylocationlistener implements LocationListener{
@Override
public void onLocationChanged(Location location) {
if(location!=null)
{
double lat = location.getLatitude();
double lng = location.getLongitude();
textlat.setText(Double.toString(lat));
textlong.setText(Double.toString(lng));
}
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status,
Bundle extras) {
// TODO Auto-generated method stub
}
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:id="@+id/textlat"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_marginTop="16dp"
android:text=""
android:ems="10">
</TextView>
<TextView
android:id="@+id/textlong"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="25dp"
android:text=""
android:ems="10">
</TextView>
</RelativeLayout>
AndroidMainfest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.checkinapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.checkinapp.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
我正在尝试将用户的纬度和经度显示到文本视图.但我没有得到结果.谢谢.
I'm trying to display the latitude and longitude of user to a textview. But I'm not getting the result. Thanks.
使用这个类在你的应用程序中获取当前位置,这对我来说非常有用
Use this class for getting Current Location in your App this is perfectly works for me
/**
* Gps location tracker class
* to get users location and other information related to location
*/
public class GpsLocationTracker extends Service implements LocationListener
{
/**
* context of calling class
*/
private Context mContext;
/**
* flag for gps status
*/
private boolean isGpsEnabled = false;
/**
* flag for network status
*/
private boolean isNetworkEnabled = false;
/**
* flag for gps
*/
private boolean canGetLocation = false;
/**
* location
*/
private Location mLocation;
/**
* latitude
*/
private double mLatitude;
/**
* longitude
*/
private double mLongitude;
/**
* min distance change to get location update
*/
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATE = 10;
/**
* min time for location update
* 60000 = 1min
*/
private static final long MIN_TIME_FOR_UPDATE = 60000;
/**
* location manager
*/
private LocationManager mLocationManager;
/**
* @param mContext constructor of the class
*/
public GpsLocationTracker(Context mContext) {
this.mContext = mContext;
getLocation();
}
/**
* @return location
*/
public Location getLocation() {
try {
mLocationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
/*getting status of the gps*/
isGpsEnabled = mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
/*getting status of network provider*/
isNetworkEnabled = mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGpsEnabled && !isNetworkEnabled) {
/*no location provider enabled*/
} else {
this.canGetLocation = true;
/*getting location from network provider*/
if (isNetworkEnabled) {
mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_FOR_UPDATE, MIN_DISTANCE_CHANGE_FOR_UPDATE, this);
if (mLocationManager != null) {
mLocation = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (mLocation != null) {
mLatitude = mLocation.getLatitude();
mLongitude = mLocation.getLongitude();
}
}
/*if gps is enabled then get location using gps*/
if (isGpsEnabled) {
if (mLocation == null) {
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_FOR_UPDATE, MIN_DISTANCE_CHANGE_FOR_UPDATE, this);
if (mLocationManager != null) {
mLocation = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (mLocation != null) {
mLatitude = mLocation.getLatitude();
mLongitude = mLocation.getLongitude();
}
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return mLocation;
}
/**
* call this function to stop using gps in your application
*/
public void stopUsingGps() {
if (mLocationManager != null) {
mLocationManager.removeUpdates(GpsLocationTracker.this);
}
}
/**
* @return latitude
* <p/>
* function to get latitude
*/
public double getLatitude() {
if (mLocation != null) {
mLatitude = mLocation.getLatitude();
}
return mLatitude;
}
/**
* @return longitude
* function to get longitude
*/
public double getLongitude() {
if (mLocation != null) {
mLongitude = mLocation.getLongitude();
}
return mLongitude;
}
/**
* @return to check gps or wifi is enabled or not
*/
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* function to prompt user to open
* settings to enable gps
*/
public void showSettingsAlert() {
AlertDialog.Builder mAlertDialog = new AlertDialog.Builder(new ContextThemeWrapper(mContext, R.style.AppTheme));
mAlertDialog.setTitle("Gps Disabled");
mAlertDialog.setMessage("gps is not enabled . do you want to enable ?");
mAlertDialog.setPositiveButton("settings", new OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
Intent mIntent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(mIntent);
}
});
mAlertDialog.setNegativeButton("cancle", new OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
dialog.cancel();
}
});
final AlertDialog mcreateDialog = mAlertDialog.create();
mcreateDialog.show();
}
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
}
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
&这样使用它
GpsLocationTracker mGpsLocationTracker = new GpsLocationTracker(YourActivity.this);
/**
* Set GPS Location fetched address
*/
if (mGpsLocationTracker.canGetLocation())
{
latitude = mGpsLocationTracker.getLatitude();
longitude = mGpsLocationTracker.getLongitude();
Log.i(TAG, String.format("latitude: %s", latitude));
Log.i(TAG, String.format("longitude: %s", longitude));
}
else
{
mGpsLocationTracker.showSettingsAlert();
}
&不要忘记在 Manifest.xml 中设置权限
& don't forget to set permission in Manifest.xml
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
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