【问题标题】:Can't get current location android on location changed无法在位置更改时获取当前位置 android
【发布时间】:2016-08-16 22:59:40
【问题描述】:

我正在使用的 PC 和 android studio (macbook) 有什么问题。 我尝试了不同的方法来获取当前位置,但每次我失败时,我都会按照不同的教程使用不同的程序来获取位置,但没有运气。我遵循this 教程,但它对我不起作用,但我下载了它工作正常的源代码,如果我创建新项目并尝试从示例项目添加文件它不起作用。我也试过thisthis 但没有运气。

我的安卓工作室有什么问题吗?请问我有什么解决办法。

我还更新了工具和 SDK。

我确实从here 尝试过这段代码

    package com.iorzb.gpstest;

import android.Manifest;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
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.support.v4.app.ActivityCompat;
import android.util.Log;

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;
            if (isNetworkEnabled) {
                if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    // TODO: Consider calling
                    //    ActivityCompat#requestPermissions
                    // here to request the missing permissions, and then overriding
                    //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                    //                                          int[] grantResults)
                    // to handle the case where the user grants the permission. See the documentation
                    // for ActivityCompat#requestPermissions for more details.
                    return null;
                }
                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;
}

}

相同的代码在下载的项目中有效,但在新项目中无效。

【问题讨论】:

标签: android android-studio locationmanager


【解决方案1】:

忘记你读过或做过的一切。使用 Google 的FusedLocationProviderApi

这是侦听位置更新的最简单方法。

您不必处理启用了哪个位置提供商(网络、gps 等)。您只需要位置更新,所以使用FusedLocationProviderApi 轻松获取它们

它被描述为here。您可以在几分钟内将其实施到您的应用程序中。

Here 是示例。

注意:您需要以下依赖项:

compile 'com.google.android.gms:play-services:8.1.0'

【讨论】:

    【解决方案2】:

    我使用这个代码,这个代码完全适合我,请试试这个代码。 并且,请检查手机并确保 GPS 已启用。

    公共类 GPSTracker 扩展服务实现 LocationListener { 私有最终上下文 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) {
    
        latitude = location.getLatitude();
        longitude = location.getLongitude();
    
        System.out.println("onLocationChanged.." + latitude);
        System.out.println("onLocationChanged.." + longitude);
    }
    
    @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;
    }
    

    }

    【讨论】:

    • 我遵循您的代码,如果我注释掉 onLocationChanged 函数内部部分,它可以正常工作,否则它会崩溃
    • 你实现了 OnLocationChangedListener 吗?
    【解决方案3】:

    你在用模拟器吗?如果是这样,除非您使用特定工具来模拟位置,否则位置功能将不起作用。 或者您可以尝试使用物理设备测试您的应用。

    【讨论】:

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