实验05-android-广播定位

实验目的

1).静态注册：直接在AndroidManifest.xml文件中进行注册。
2).动态注册：动态注册时，无须在AndroidManifest中注册组件。直接在代码中通过调用Context的registerReceiver函数动态注册广播。

静态广播与动态广播的区别

1. 动态注册的广播永远要快于静态注册的广播,不管静态注册优先级设置的多高,不管动态注册的优先级有多低,

2. 在同一个优先级下,谁先启动的快,谁将先接收到广播

3. 动态注册广播不是常驻型广播,也就是广播跟随activity的省命周期(在Activity结束前,移除广播接收器),静态注册是常驻型,也就是说当前应用程序关闭后,如果有信息广播来,程序也会被系统调用自动运行,

4. PendingIntent是一个特殊的Intent,主要区别是Intent是立马执行,PendingIntent是待确定的Intent

5. PendingIntent的实际操作上是传入的Intent的操作,使用PendingIntent的目的主要是用于所包含的intent是否满足某些条件
   获取PendingIntent有三种方式:

6. getActivity(Context context, int requestCode, Intent intent, int flags)

7. getService(Context context, int requestCode, Intent intent, int flags)

8. getBroadCast(Context context, int requestCode, Intent intent, int flags)

PendingIntent的flags参数

1. FLAG_CANCEL_CURRENT
2. FLAG_UPDATE_CURRENT
3. FLAG_NO_CREATE
4. FLAG_ONE_SHOT

LocationManager常量可在Intent中携带。
1、LocationManager.KEY_LOCATION_CHANGED
2、LocationManager.KEY_PROVIDER_ENABLED
3、LocationManager.KEY_PROXIMITY_ENTERING
4、LocationManager.KEY_STATUS_CHANGED

1、requestLocationUpdates（provider，time，dis，listenter）；
2、 requestLocationUpdates（provider，time，dis，PendingIntent）；

新建一个Android项目
AndroidManifest.xml添加权限

<uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
    <uses-permission  android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FIND_LOCATION"/>
    <uses-permission android:name="android.permission.BROADCAST_SMS"/>

LocationReceiver.java

package com.example.lu01_week10_brocast;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationManager;
import android.util.Log;

public class LocationReceiver extends BroadcastReceiver{
	public final String TAG = "LocationReceiver";

	@Override
	public void onReceive(Context context, Intent intent) {
		// TODO Auto-generated method stub
		Location location = intent.getParcelableExtra(LocationManager.KEY_LOCATION_CHANGED);
		if(location != null){
			onLocationReceived(context,location);
		}if(intent.hasExtra(LocationManager.KEY_PROVIDER_ENABLED)){
			boolean enabled = intent.getBooleanExtra(LocationManager.KEY_PROVIDER_ENABLED, false);
			onProviderEnabledChanged(enabled);
		}
	}

	private void onProviderEnabledChanged(boolean enabled) {
		Log.v(TAG, "Provider"+(enabled ? "enabled":"disabled"));
		
	}
	private void onLocationReceived(Context context, Location location) {
		// TODO Auto-generated method stub
		Log.v(TAG, this+"Got location from"+location.getProvider()+":"+location.getLatitude()+","+location.getLongitude());
		
	}
}

MainActivity.java

package com.example.lu01_week10_brocast;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.location.Address;
import android.location.Criteria;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationManager;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;



public class MainActivity extends Activity{
String action = "com.example.lu01_week10_brocast";
TextView textView;
Button start,stop;
LocationManager locationManager;
Location mLastlocation;

private BroadcastReceiver mBroadcastReceiver = new LocationReceiver(){
	private void onLocationReceived(Location location) {
		// TODO Auto-generated method stub
		mLastlocation= location;
		updateTextView(mLastlocation);
	}
private void onProviderEnabledChanged(boolean enabled) {
//	Gps服务提供者启动或停止时,消息提示
	String toastText = enabled?"gps_enabled":"gps_disabled";
	Toast.makeText(MainActivity.this, toastText, Toast.LENGTH_LONG).show();
}
};

protected void onCreate(android.os.Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	textView= (TextView) findViewById(R.id.TextView);
	start = (Button) findViewById(R.id.start);
	stop= (Button) findViewById(R.id.stop);
	locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
	start.setOnClickListener(new OnClickListener() {
		
		@Override
		public void onClick(View arg0) {
			startLocationupdates();
		}
	});
	stop.setOnClickListener(new OnClickListener() {
		
		@Override
		public void onClick(View arg0) {
			stopLocationUpdates();
			
		}
	});	
};
protected void stopLocationUpdates() {
	PendingIntent pi = getLocationPendingIntent(false);
	if(pi != null){
		locationManager.removeUpdates(pi);
		pi.cancel();
		textView.setText("stop listener");
		Toast.makeText(MainActivity.this, "pi canceled", 2000).show();
	}	
}
protected void startLocationupdates() {
	// 要求LocationManager通过GPS或NETWORK定位装置提供实时的定位数据更新
	String bestProvider = locationManager.getBestProvider(getCriteria(), true);
//	获取最近一次地理位置信息,避免用户开启定位时的长时间等待,
	Location LastKnownLocation = locationManager.getLastKnownLocation(bestProvider);
	updateTextView(LastKnownLocation);
	if(LastKnownLocation != null){
		broadcastLocation(LastKnownLocation);
	}
	PendingIntent pi = getLocationPendingIntent(true);
	locationManager.requestLocationUpdates(bestProvider, 1, 1, pi);
	
}
//发送最近一次地理位置信息的广播
private PendingIntent getLocationPendingIntent( boolean shouldCreate) {
	Intent broacast = new Intent(action);
	int flags = shouldCreate ? 0:PendingIntent.FLAG_NO_CREATE;
	return PendingIntent.getBroadcast(MainActivity.this, 0, broacast, PendingIntent.FLAG_CANCEL_CURRENT);
}
private void start() {
	// TODO Auto-generated method stub
String bestProvider = locationManager.getBestProvider(getCriteria(),true);
Location location = locationManager.getLastKnownLocation(bestProvider);

updateTextView(location);
if(location != null){
	broadcastLocation(location);
}
PendingIntent pi = getLocationPendingIntent();
locationManager.requestLocationUpdates(bestProvider, 0, 0, pi);
}

private PendingIntent getLocationPendingIntent() {
	Intent intent = new Intent(action);
	PendingIntent.getBroadcast(MainActivity.this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
	return null;
}


private void broadcastLocation(Location location) {
	Intent intent = new Intent(action);
	intent.putExtra(LocationManager.KEY_LOCATION_CHANGED,location );
	sendBroadcast(intent);
}
private Criteria getCriteria() {
//设置Criteria
	Criteria criteria= new Criteria();
	criteria.setAccuracy(Criteria.ACCURACY_FINE);
//	设置是否要求速度
	criteria.setSpeedRequired(false);
//	设置是否允许运营商收费
	criteria.setCostAllowed(false);
//	设置是否需要方位消息
	criteria.setBearingRequired(false);
//	设置是否需要海拔消息
	criteria.setAltitudeRequired(false);
//	设置对电源的需求
	criteria.setPowerRequirement(Criteria.POWER_LOW);
	
	return criteria;
}
private void updateTextView(Location location) {
	// TODO Auto-generated method stub	// TODO Auto-generated method stub
//	Address address = getAddress( this,location);
	StringBuilder stringBuilder = new StringBuilder();
	if(location !=null){
		stringBuilder.append("当前经度是:"+location.getLongitude()+"\n");
		stringBuilder.append("当前纬度是"+location.getLatitude()+"\n");
		stringBuilder.append("当前海拔是"+location.getAltitude()+"\n");
		stringBuilder.append("当前时间是"+location.getTime()+"\n");
//		stringBuilder.append("当前国家是"+address.getCountryName()+"\n");
//		stringBuilder.append("当前省份是"+address.getAdminArea()+"\n");
		
		textView.setText(stringBuilder.toString());
	}else {
		textView.setTag("location is null");
	}
	
}

private Address getAddress(Context context,Location location) {
	// TODO Auto-generated method stub
	Geocoder gecoder= new Geocoder(context,Locale.getDefault());
	try {
		List<Address> lists = gecoder.getFromLocation(location.getLongitude(), location.getLatitude(), 1);
		if(lists.size() >0){
			return lists.get(0);
		}
	} catch (IOException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	return null;

}


}

实验结果:

stop后

项目需要注意添加权限,Criteria用于找到合适的地理位置提供者,有三种:gps,移动网络,主动发送位置
静态广播是在配置文件AndroidManifest.xml进行注册,常驻内存的广播
动态广播是在代码里面注册,内存是随着应用程序的结束而结束

PendingIntent是Intent的特殊形式,两者没有太大的变化

本文地址：https://blog.csdn.net/weixin_44123412/article/details/107493316