java - Android中的定位方法不起作用

Question

我正在学习一个教程，但陷入了一些代码中。问题是我无法将当前坐标获取到我的textView（id：red）中，并且它不会更改状态。我怀疑该错误是未调用方法onLocationChanged()。我也随附了Java程序和布局xml文件。感谢您的帮助！

Android MainActivity.java

package com.example.wepicit;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.widget.Button;
import android.widget.TextView;
import android.view.View;
import android.content.Context;
import android.content.Intent;
import android.view.View.OnClickListener;
import android.location.Location;
import android.location.LocationManager;
import android.location.LocationListener;

import com.facebook.*;
import com.facebook.model.*;


public class MainActivity extends Activity implements LocationListener{

    protected LocationManager locationManager;
    protected LocationListener locationListener;
    Location newLocation = new Location(LocationManager.GPS_PROVIDER);
    protected Context context;
    String lat;
    String provider; 
    protected String gps_enabled,network_enabled;
    Button button;
    TextView text;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
    }

    @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 void onLocationChanged(Location location) {
        // TODO Auto-generated method stub
        newLocation.set(location);
        //System.out.println("Lat:"+ location.getLatitude() +" Long:"+ location.getLongitude());
        text = (TextView) findViewById(R.id.red);
        text.setText("Lat:"+ newLocation.getLatitude() +" Long:"+ newLocation.getLongitude());
        Log.d("Lat:"+ newLocation.getLatitude() +" Long:"+ newLocation.getLongitude(), gps_enabled);
    }

    @Override
    public void onProviderDisabled(String arg0) {
        // TODO Auto-generated method stub
        Log.d("Latitude","disable");
    }

    @Override
    public void onProviderEnabled(String arg0) {
        // TODO Auto-generated method stub
        Log.d("Latitude","enable");
    }

    @Override
    public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
        // TODO Auto-generated method stub
        Log.d("Latitude","status");
    }

}

布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/textview1"
    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" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="35dp"
        android:text="Tester" />

    <TextView
        android:id="@+id/red"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="39dp"
        android:text="TextView" />

</RelativeLayout>

Answer 1

尝试使用此代码，这将为您提供GPS或网络提供商的位置。

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) {
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                Log.d("Network", "Network Enabled");
                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", "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;
}