Android中GPS定位的简单应用

时间：2023-11-23 08:14:08

在Android中通过GPS获得当前位置，首先要获得一个LocationManager实例，通过该实例的getLastKnownLocation()方法获得第一个的位置，该方法的说明如下：

void android.location.LocationManager.requestLocationUpdates(String provider, long minTime, float minDistance, LocationListener listener)

provider即定位方式，可以采用GPS定位(LocationManager.GPS_PROVIDER)或者网络定位(LocationManager.NETWORK_PROVIDER)，本文是GPS定位，因此使用LocationManager.GPS_PROVIDER。minTime是位置更新的间隔时间。listener是位置改变的监听器，自己定义一个LocationListener()，重写onLocationChanged()，加入位置改变时的动作。

布局文件：

<LinearLayout 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:orientation="vertical"

    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/txt_time"

        style="@style/my_text"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="时间:" />

    <TextView

        android:id="@+id/txt_lat"

        style="@style/my_text"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="经度:" />

    <TextView

        android:id="@+id/txt_lng"

        style="@style/my_text"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="纬度:" />

</LinearLayout>

MainActivity.java文件：

package com.hzhi.my_gps;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Timer;

import java.util.TimerTask;

import android.location.Criteria;

import android.location.Location;

import android.location.LocationListener;

import android.location.LocationManager;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.app.Activity;

import android.content.Context;

import android.view.Menu;

import android.widget.TextView;

public class MainActivity extends Activity {

	TextView txt_time;

	TextView txt_lat;

	TextView txt_lng;

	LocationManager lom;

	Location loc;

	Double lat;

	Double lng;

	SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

	Date now;

	String str_date;

	Timer timer;

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		get_con();

		get_gps();

		timer = new Timer(true);

		timer.schedule(task, 0, 1000);

	}

	@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;

	}

	public void get_gps(){

		lom = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

		loc = lom.getLastKnownLocation(LocationManager.GPS_PROVIDER);

		if (loc != null) {

		    lat = loc.getLatitude();

		    lng = loc.getLongitude();

		    txt_lat.setText("纬度:" + String.valueOf(lat));

		    txt_lng.setText("经度:" + String.valueOf(lng));

		}

		else{

		    txt_lat.setText("纬度:未知" );

		    txt_lng.setText("经度:未知" );

		}

        Criteria criteria = new Criteria();

        criteria.setAccuracy(Criteria.ACCURACY_FINE);

        criteria.setAltitudeRequired(false);

        criteria.setBearingRequired(false);

        criteria.setCostAllowed(true);

        criteria.setPowerRequirement(Criteria.POWER_LOW);

        String provider = lom.getBestProvider(criteria, true);

		lom.requestLocationUpdates(provider, 1000, 10, los);

	}

	LocationListener los = new LocationListener(){

		public void onLocationChanged(Location location){

			if (location != null) {

			    lat = location.getLatitude();

			    lng = location.getLongitude();

			    txt_lat.setText("纬度:" + String.valueOf(lat));

			    txt_lng.setText("经度:" + String.valueOf(lng));

			}

			else{

			    txt_lat.setText("纬度:未知" );

			    txt_lng.setText("经度:未知" );

			}

		};

    	public void onProviderDisabled(String provider){

    	};

    	public void onProviderEnabled(String provider){ };

    	public void onStatusChanged(String provider, int status,

    	Bundle extras){ };

	};

	// 获取控件

	public void get_con(){

		txt_time = (TextView) findViewById(R.id.txt_time);

		txt_lat = (TextView) findViewById(R.id.txt_lat);

		txt_lng = (TextView) findViewById(R.id.txt_lng);

	}

	Handler handler = new Handler(){

		public void handleMessage(Message msg){

			switch (msg.what){

			case 1:

				get_time();

				break;

			}

		}

	};

	TimerTask task = new TimerTask(){

	      public void run() {

	          Message message = new Message();

	          message.what = 1;

	          handler.sendMessage(message);

	   }

	};

	// 获取时间

	public void get_time(){

		now = new Date(System.currentTimeMillis());

		str_date = formatter.format(now);

		txt_time.setText("时间:" + str_date);

	}

}

在AndroidManifest.xml文件中加入权限：

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

运行前先打开GPS卫星，运行结果：

Android中GPS定位的简单应用

由于在室内，并且手机质量不好，没获取出来，在室外是可以获取的。

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