本文主要用到了安卓监测网络状态变化功能,实现了WIFI,3G,无网络状态切换时发出通知的功能。
主要知识点
- service
- broadcast
- 接口回调实现
service的基本知识
service可分为
- 按运行地点分类
- 本地服务
- 远程服务
- 按按运行类型分类:
- 前台服务
- 后台服务
- 按使用方式分类:
- startService 启动的服务
- bindService 启动的服务
- startService 同时也 bindService 启动的服务
service生命周期
详情请见参考链接:
Android 中的 Service 全面总结 - - 博客频道 - CSDN.NET
Android开发之如何保证Service不被杀掉(broadcast+system/app) - 其实并不难,是你太悲观 - 博客频道 - CSDN.NET
安卓监测网络状态变化
service部分
package com.zj.servicewifi;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Binder;
import android.os.IBinder;
import android.provider.SyncStateContract.Constants;
import android.util.Log;
public class WIFIService extends Service{
int IntentId;
int NOINTENT=0;
int WIFI=1;
int GRS=2;
// 实时监听网络状态改变
private BroadcastReceiver mReceiver = new BroadcastReceiver()
{
@Override
public void onReceive(Context context, Intent intent)
{
String action = intent.getAction();
if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION))
{
Timer timer = new Timer();
timer.schedule(new QunXTask(getApplicationContext()), new Date());
}
}
};
public interface GetConnectState
{
public void GetState(int isConnected); // 网络状态改变之后,通过此接口的实例通知当前网络的状态,此接口在Activity中注入实例对象
}
private GetConnectState onGetConnectState;
public void setOnGetConnectState(GetConnectState onGetConnectState)
{
this.onGetConnectState = onGetConnectState;
}
private Binder binder = new MyBinder();
private boolean isContected = true;
@Override
public IBinder onBind(Intent intent)
{
return binder;
}
@Override
public void onCreate()
{// 注册广播
IntentFilter mFilter = new IntentFilter();
mFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION); // 添加接收网络连接状态改变的Action
registerReceiver(mReceiver, mFilter);
}
class QunXTask extends TimerTask
{
private Context context;
public QunXTask(Context context)
{
this.context = context;
}
@Override
public void run()
{
if (is3GConnected(context)&&isWifiConnected(context)==false)
{
System.out.println("hereere*************");
IntentId= 2;
}
else if(isWifiConnected(context))
{
IntentId=WIFI;
}
else
{
IntentId=NOINTENT;
}
if (onGetConnectState != null)
{
onGetConnectState.GetState(IntentId); // 通知网络状态改变
Log.i("mylog", "通知网络状态改变:" + IntentId);
}
}
/*
* 判断是3G否有网络连接
*/
private boolean is3GConnected(Context context)
{
if (context != null)
{
ConnectivityManager mConnectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mNetworkInfo = mConnectivityManager.getActiveNetworkInfo();
if (mNetworkInfo != null)
{
return mNetworkInfo.isAvailable();
}
}
return false;
}
/*
* 判断是否有wifi连接
*/
private boolean isWifiConnected(Context context)
{
if (context != null)
{
ConnectivityManager mConnectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mWiFiNetworkInfo = mConnectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (mWiFiNetworkInfo != null)
{
return mWiFiNetworkInfo.isAvailable();
}
}
return false;
}
}
public class MyBinder extends Binder
{
public WIFIService getService()
{
return WIFIService.this;
}
}
@Override
public void onDestroy()
{
super.onDestroy();
unregisterReceiver(mReceiver); // 删除广播
}
}
注意,其中用到广播接收者,广播接收者有两种注册方式,在代码中注册与在XML文件中注册,本例中在代码中注册了,如果再在XML中注册,会报错
activity中代码
package com.zj.servicewifi;
import com.zj.servicewifi.WIFIService.GetConnectState;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;
public class MainActivity extends Activity {
protected String TAG = "mylog";
WIFIService receiveMsgService;
int IntentID=0;
ServiceConnection sc;
boolean state;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sc=new ServiceConnection() {
@Override
public void onServiceDisconnected(ComponentName name) {
// TODO Auto-generated method stub
}
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
// TODO Auto-generated method stub
receiveMsgService = ((WIFIService.MyBinder) service)
.getService();
receiveMsgService.setOnGetConnectState(new GetConnectState() { // 添加接口实例获取连接状态
@Override
public void GetState(int id) {
if (IntentID != id) { // 如果当前连接状态与广播服务返回的状态不同才进行通知显示
IntentID = id;
if (IntentID==0) {// 已连接
handler.sendEmptyMessage(0);
} else if(IntentID==1){// 未连接
handler.sendEmptyMessage(1);
} else if(IntentID==2)
{
handler.sendEmptyMessage(2);
}
}
}
});
}
};
}
public void bind(View view)
{
startService(new Intent(MainActivity.this,WIFIService.class));
bindService(new Intent(MainActivity.this, WIFIService.class), sc, getApplicationContext().BIND_AUTO_CREATE);
state = true;
}
public void unbind(View view)
{
if(state ){
unbindService(sc);
state = false;
}
}
public void start(View view)
{
}
public void stop(View view)
{
}
@Override
protected void onDestroy()
{
// TODO Auto-generated method stub
super.onDestroy();
if(state){
unbindService(sc);
state = false;
}
}
Handler handler = new Handler() {
public void handleMessage(Message msg) {
switch (msg.what) {
case 0:
Toast.makeText(MainActivity.this, "网络未经连接" ,Toast.LENGTH_LONG).show();
break;
case 1:// 已连接
Toast.makeText(MainActivity.this, "WIFI已经连接" ,Toast.LENGTH_LONG).show();
break;
case 2:// 未连接
Toast.makeText(MainActivity.this, "3G已连接" ,Toast.LENGTH_LONG).show();
break;
default:
break;
}
;
};
};
}
本例中最重要的一点就是在service中定义了一个接口,在activity中实例化,则在service中调用方法的时候,会调用在activity中实例化的方法,不知道这是什么设计模式,只觉得很神奇。
参考链接:
android 通过Service和Receiver来监听网络状态 - - ITeye技术网站
Android判断设备网络连接状态,并判断连接方式 - lzan13的专栏 - 博客频道 - CSDN.NET