android學習之廣播發送與檢測網絡開啓服務

android四大組件之BroadcastReceiver和service使用；

BroadcastReceiver一般分爲普通廣播，有序廣播，異步廣播，開啓方式又分爲靜態註冊，和動態註冊兩種類型；

service:啓動service又包括通過啓動服務和綁定服務兩種類型；

四大基本組件都可以通過活動清單文件註冊；

看例子：通過不同方式發送廣播，和獲取系統服務檢查網絡

package com.example.boardcastreciver;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity  implements OnClickListener{
	private Button btn,btn1,checknet;
	private Boolean status;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		btn =(Button) findViewById(R.id.sendbd);
		btn.setOnClickListener(this);
		
		btn1 =(Button) findViewById(R.id.send);
		btn1.setOnClickListener(this);
		
		checknet =(Button) findViewById(R.id.checknet);
		checknet.setOnClickListener(this);
		
		createCaster();
		
	}
	
	@Override
	protected void onResume() {
		super.onResume();
		//createCaster();
	}
	
	public void createCaster(){
		//先動態註冊廣播
		IntentFilter filter =new IntentFilter("com.example.boardcastreciver.MyDBcaster");
		MyBDcaster cast =new MyBDcaster();
		registerReceiver(cast, filter);
		//再發廣播
		Intent intent =new Intent();
		intent.putExtra("msg", "這是剛纔發送的一個消息！");
		intent.putExtra("body", "沙特武裝組織進攻，影響國際油價");
		intent.setAction("com.example.boardcastreciver.MyDBcaster");
		sendBroadcast(intent);
		
	}
	
	public  Boolean cknetStatus(Context context){
		if(context!=null){
		ConnectivityManager manager=(ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE);
		NetworkInfo info=manager.getActiveNetworkInfo();
		if(info!=null){
			return true;
			}
		}
		
		return false;
	}
	
	public void onClick(View v) {
     
		switch (v.getId()) {
		case R.id.sendbd:
			Intent intent =new Intent();
			intent.putExtra("msg", "這是剛纔發送的一個消息！");
			intent.putExtra("body", "沙特武裝組織進攻，影響國際油價");
			intent.setAction("com.example.boardcastreciver.MyDBcaster");
			sendBroadcast(intent);
			break;
		case R.id.send:
			Intent intent1 =new Intent();
			intent1.putExtra("msg", "發送的是一個有序消息！");
			intent1.putExtra("body", "快訊：沙特武裝組織進攻，影響國際油價");
			intent1.setAction("com.example.boardcastreciver.MyDBcaster");
			sendOrderedBroadcast(intent1, null);
			break;
			
		case R.id.checknet:
			if(cknetStatus(MainActivity.this)==true){
				Toast.makeText(MainActivity.this, "網絡連接正常", Toast.LENGTH_SHORT).show();
			}else{
				Toast.makeText(MainActivity.this, "網絡連接失敗", Toast.LENGTH_SHORT).show();
			}
			break;
		default:
			break;
		}
		
	}

	
}

 <receiver 
            android:name=".MyBDcaster">
           <intent-filter>
               <action android:name="com.example.boardcastreciver.MyDBcaster"/>
           </intent-filter> 
        </receiver>

package com.example.boardcastreciver;


import android.app.Notification;
import android.app.NotificationManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class MyBDcaster extends BroadcastReceiver {

	@Override
	public void onReceive(Context context, Intent intent) {

		String msg =intent.getStringExtra("msg");
		String body =intent.getStringExtra("body");
		System.out.println("接受到的廣播信息爲："+msg);

		NotificationManager manager =(NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
		Notification notification =new Notification(R.drawable.ic_launcher, msg,System.currentTimeMillis());
		notification.setLatestEventInfo(context, msg, body, null);
		manager.notify(1, notification);
		
	}
	
	

}