使用 GPS 获取用户的当前位置

问题描述

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.

推荐答案

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"/>

这篇关于使用 GPS 获取用户的当前位置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持html5模板网！