android service broadcastreceiver intentfilter

service 组件，和UI并不进行交互，运行在后台，可以和其他组件进行交互

broadcastreceiver，广播是一种广泛运用的在应用程序之间传输信息的机制 。而 BroadcastReceiver 是对发送出来的广播进行过滤接收并响应的一类组件

intentfilter Intent类似于Windows中的消息，而intentfilter可以理解为消息过滤器

下面我们用例子来说明如何运用这三种组件

首先，我们建立一个Serivce，他的作用是每间隔一秒生成一个随机数，并将随机数放到Intent中

然后声明一个action,在Service中进行广播，在MainActivity中来接收这个广播，并显示随机数.

为了可以使服务停止，我们另外建立了一个BroadCastReceiver 来接受广播，当判断广播内容是停止服务时，调用停止服务.

在服务的onCreate中，注册广播接收器组件，在onDestory中取消注册广播接收组件

在onStartCommand中声明了一个IntentFilter用来过滤广播消息，设定Action

先来看下Service和停止服务用的BroadCastReceiver 

package com.ssln.broadcastreceiver_service_intentfilter;



import android.app.Service;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.os.IBinder;

import android.util.Log;



public class MyService extends Service {



    public final static int CMD_STOP_SERVICE=1;    //停止服务

    private CommandReciver cmdReceiver;

    private boolean flag;

    public final static String action="com.ssln.broadcastreceiver_service_intentfilter.MyService";

    private static final String TAG = "MyService";



    @Override

    public IBinder onBind(Intent intent) {

        return null;

    }



    @Override

    public void onCreate() {

        flag = true;

        cmdReceiver = new CommandReciver();

        super.onCreate();

        Log.i(TAG, "MyService-->onCreate");

    }



    @Override

    public int onStartCommand(Intent intent, int flags, int startId) {

        Log.i(TAG, "MyService-->onStartCommand");

        IntentFilter filter = new IntentFilter(); // 建立IntentFilter对象

        filter.addAction(action);

        // 注册广播接收，并设置接受的action

        registerReceiver(cmdReceiver, filter);

        Log.i(TAG, "MyService-->注册BroadcastReceiver成功");

        // 启动线程

        doJob();

        return super.onStartCommand(intent, flags, startId);

    }



    @Override

    public void onDestroy() {

        Log.i(TAG, "MyService-->onDestroy");

        // 取消广播接受的注册

        unregisterReceiver(cmdReceiver);

        Log.i(TAG, "MyService-->取消注册BroadcastReceiver成功");

        super.onDestroy();

    }



    /**

     * 执行线程

     */

    private void doJob() {

        new Thread() {

            public void run() {

                while (flag) {

                    try {

                        Thread.sleep(1000);// 睡眠一秒

                    } catch (Exception exp) {

                        exp.printStackTrace();

                    }

                    Intent intent=new Intent();

                    //设置action

                    intent.setAction(action);

                    //设置随机数

                    intent.putExtra("data", Math.random());

                    //发送广播

                    sendBroadcast(intent);

                    Log.i(TAG, "MyService-->doJob");

                }

            }



        }.start();

    }



    /**

     * 为了Service的停止，为Service注册Broadcast Receiver组件

     * @author ssln

     *

     */

    private class CommandReciver extends BroadcastReceiver {



        @Override

        public void onReceive(Context context, Intent intent) {

            int cmd=intent.getExtras().getInt("cmd",-1);

            if(cmd==CMD_STOP_SERVICE){

                //停止线程

                flag=false;

                //停止服务

                stopSelf();

            }

        }



    }

}

在来看看MainActivity.java

在onclick中，我们看到btnStart是启动了我们自定义的服务，而btnStop是发送了一个停止服务的广播内容

package com.ssln.broadcastreceiver_service_intentfilter;



import android.app.Activity;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.TextView;



public class MainActivity extends Activity implements OnClickListener{



    private static final String TAG = "MainActivity";

    private TextView tvData;

    private Button btnStart,btnStop;

    private DataReceiver datareceiver;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

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

        btnStart=(Button)findViewById(R.id.btnStart);

        btnStop=(Button)findViewById(R.id.btnStop);

        

        btnStart.setOnClickListener(this);

        btnStop.setOnClickListener(this);

    }

 

    /**

     * 注册广播接收

     */

    private void RegDataReceiver()

    {

        if(datareceiver==null)

        {

            //注册action

            datareceiver=new DataReceiver();

            IntentFilter filter=new IntentFilter();

            //添加接受的action

            filter.addAction(MyService.action);

            //注册

            registerReceiver(datareceiver, filter);

            Log.i(TAG, "注册广播成功");

        }

    }

    /**

     * 取消注册

     */

    private void UnRegDataReceiver()

    {

        if(datareceiver!=null)

        {

            unregisterReceiver(datareceiver);

            datareceiver=null;

            Log.i(TAG, "取消注册广播");

        }

    }



    @Override

    protected void onResume() {

        RegDataReceiver();

        Log.i(TAG, "onResume");

        super.onResume();

    }



    @Override

    protected void onPause() {

        UnRegDataReceiver();

        Log.i(TAG, "onPause");

        super.onPause();

    }





    /**

     * 接受线程发送过来的数据

     * @author ssln

     *

     */

    private class DataReceiver extends BroadcastReceiver{



        @Override

        public void onReceive(Context context, Intent intent) {

            double data=intent.getDoubleExtra("data", 0.0d);

            if(data==0)

            {

                int cmd=intent.getIntExtra("cmd", -1);

                if(cmd==MyService.CMD_STOP_SERVICE)

                    tvData.setText("停止服务成功");

                else

                    tvData.setText("未知数据");

            }

            else

            {

                tvData.setText("Service 发送的数据为: "+String.valueOf(data));

            }

        }

        

    }



    @Override

    public void onClick(View v) {

        if(v==btnStart)

        {

            Intent myIntent=new Intent(MainActivity.this,MyService.class);

            startService(myIntent);

            tvData.setText("启动服务成功 ");

        }

        else if(v==btnStop)

        {

            Intent myIntent=new Intent();

            myIntent.setAction(MyService.action);

            myIntent.putExtra("cmd", MyService.CMD_STOP_SERVICE);

            sendBroadcast(myIntent);

        }

    }

}

 

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:id="@+id/LinearLayout1"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context="com.ssln.broadcastreceiver_service_intentfilter.MainActivity" >



    <TextView

        android:id="@+id/tvData"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="TextView" />



    <Button

        android:id="@+id/btnStart"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="启动服务" />



    <Button

        android:id="@+id/btnStop"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="停止服务" />



</LinearLayout>

最后，记得在AndroidManifest.xml中注册我们的服务，否则启动不了的啊

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.ssln.broadcastreceiver_service_intentfilter"

    android:versionCode="1"

    android:versionName="1.0" >



    <uses-sdk

        android:minSdkVersion="17"

        android:targetSdkVersion="20" />



    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name=".MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />



                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

        <!-- 注册服务 -->

        <service android:name="MyService"></service>

    </application>



</manifest>

看下效果,每秒生成的随机数都不同

我们点击停止后，会停止服务