android广播事件处理broadcast receive

一.Broadcast Receive为广播接收器，它和事件处理机制类似，只不过事件的处理机制是程序组件级别的，而广播处理机制是系统级别的。

Broadcast Receiver用于接收并处理广播通知（broadcast announcements）。多数的广播是系统发起的，如地域变换、电量不足、来电来信等。程序也可以播放一个广播。程序可以有任意数量的 broadcast receivers来响应它觉得重要的通知。broadcast receiver可以通过多种方式通知用户：启动activity、使用NotificationManager、开启背景灯、振动设备、播放声音等，最典型的是在状态栏显示一个图标，这样用户就可以点它打开看通知内容。

通常我们的某个应用或系统本身在某些事件（电池电量不足、来电来短信）来临时会广播一个Intent出去，我们可以利用注册一个Broadcast Receiver来监听到这些Intent并获取Intent中的数据。

二.事件的广播比价简单，构建Intent对象，调用sendBroadcast()方法将广播发出。事件的接收是通过定义一个继承BroadcastReceiver类来实现，继承该类后覆盖其onReceiver方法，并在该方法中相应事件。
  MainActivity：
   Intent intent=new Intent();
   intent.setAction(MY_ACTION);
   intent.putExtra("msg","请回复")；
   sendBroadcast(intent);
  MyReceiver:
   public calss MyReceiver extends BroadcastReceiver{
       public void onReceiver(Context ctx,intent intent){
            //从Intent中获得信息
           String msg=intent.getString("msg");
          Toast.makeText(ctx,msg,Toast.LENGTH_LONG).show()


          }


       }
  
三.系统广播事件的使用
   1. 这些广播是系统自动发出，我们直接定义事件接收器进行接收。
      通过配置文件注册
      MyReceiver2:
     public class MyReceiver2 extends BroadcastReceiver{
            
           public void onReceiver( Context context,Intent intent){
                  Log.i("my_tag","BOOT_COMPLETED")
                    
                     }    


                 }
       AndroidMainifest.xml:
      <receiver android:name="MyReceiver2">
          <intent-filter>
            <android android:name="android.intent.android.BOOT_COMPLETED">
         </intent-filter>
       </receiver>
       通过代码注册：
       IntentFilter filter=new IntentFilter();//实例化
       //实例化Receiver
       MyReceiver2=new MyReceiver2();
      //注册Receiver
       registerReceiver（r,filter）;
      //注销Receiver
       unregisterReceiver(r);
四.Notification和NotificationManager的使用
   Broadcast Receiver组件并没有提供可视化的界面来显示广播信息。这里我们可以使用Notification和Notification Manager来实现可视化的信息的界面，通过使用它们 ,我们可以显示广播信息的内容，图标及震动信息。
五.AlarmManager的使用
   现在的手机普遍都会有一个闹钟功能，如果使用Android来实现一个闹钟，可以使用AlarmManager来实现。AndroidManager提供了一种系统级的提示服务，允许你安排在将来的某个时间执行一个任务，AlarmManager对象一般不直接实例化，而是通过Context.getSystemService(Context.ALARM_SERVICE)方法获得。

实例一、自定义broadcast receive来处理广播事件

/Chapter08_Broadcast_Receiver1/src/com/amaker/ch08/app/MainActivity.java

package com.amaker.ch08.app;

import com.amaker.ch08.app.R;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
/**
 * 
 * 发出广播
 */
public class MainActivity extends Activity {
    // 定义一个Action常量
    private static final String MY_ACTION = "com.amaker.ch08.action.MY_ACTION";
    // 定义一个Button对象
    private Button btn;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 设置当前布局视图
        setContentView(R.layout.main);
        btn = (Button)findViewById(R.id.Button01);
        // 为按钮设置单击监听器
        btn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // 实例化Intent对象
                Intent intent = new Intent();
                // 设置Intent action属性
                intent.setAction(MY_ACTION);
                // 为Intent添加附加信息
                intent.putExtra("msg", "地瓜地瓜，我是土豆，收到请回复，收到请回复！");
                // 发出广播
                sendBroadcast(intent);
            }
        });
    }
}

自定义广播事件的使用

/Chapter08_Broadcast_Receiver1/src/com/amaker/ch08/app/MyReceiver.java

package com.amaker.ch08.app;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

/**
 * 接收广播
 */
public class MyReceiver extends BroadcastReceiver{
    
    @Override
    public void onReceive(Context cxt, Intent intent) {
        // 从Intent中获得信息
        String msg = intent.getStringExtra("msg");
        // 使用Toast显示
        Toast.makeText(cxt, msg, Toast.LENGTH_LONG).show();
    }
}

/Chapter08_Broadcast_Receiver1/src/com/amaker/ch08/app/MyReceiver2.java

package com.amaker.ch08.app;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

/**
 * 
 * 显示系统启动完成广播接收器
 */
public class MyReceiver2 extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {
        // 显示广播信息
        Log.i("my_tag", "BOOT_COMPLETED~~~~~~~~~~~~~~~~");
    }

}

系统广播事件的使用

/Chapter08_Broadcast_Receiver1/res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

    <Button 
        android:text="发出广播..." 
        android:id="@+id/Button01" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"/>
        
</LinearLayout>

/Chapter08_Broadcast_Receiver1/AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.amaker.ch08.app"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <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>
        
        <receiver android:name="MyReceiver">
            <intent-filter>
                <action  android:name="com.amaker.ch08.action.MY_ACTION"/>
            </intent-filter>
        </receiver>
        
        <receiver android:name="MyReceiver2">
            <intent-filter>
                <action  android:name="android.intent.action.BOOT_COMPLETED"/>
            </intent-filter>
        </receiver>
        
    </application>
    <uses-sdk android:minSdkVersion="3" />
</manifest> 

二、notification和notificationmanager的使用

        1、获取系统级的服务notificationmanager

        String service = NOTIFICATION_SERVICE;
        NotificationManager nm = (NotificationManager)getSystemService(service);
        
        2、实例化Notification
        Notification n = new Notification();
        // 设置显示图标，该图标会在状态栏显示
        int icon = n.icon = R.drawable.icon;
        // 设置显示提示信息，该信息也会在状态栏显示
        String tickerText = "Test Notification";
        // 显示时间
        long when = System.currentTimeMillis();
        n.icon = icon;
        n.tickerText = tickerText;
        n.when = when;

        // 也可以通过这种构造方法来设置
        Notification n1 = new Notification(icon, tickerText, when); 
        
        3、实例化Intent
        Intent intent = new Intent(this, MainActivity_Temp.class);
        // 获得PendingIntent
        PendingIntent pi = PendingIntent.getActivity(this, 0, intent, 0);
        // 设置事件信息
        n.setLatestEventInfo(this, "My Title", "My Content", pi); 
        n.defaults |= Notification.DEFAULT_SOUND;
        n.sound = Uri.parse("file:///sdcard/sound.mp3");
        n.sound = Uri.withAppendedPath(Audio.Media.INTERNAL_CONTENT_URI, "6");

        n.defaults |= Notification.DEFAULT_VIBRATE;
        long[] vibrate = {0,50,100,150};
        n.vibrate = vibrate; 
        n.defaults |= Notification.DEFAULT_LIGHTS;
        n.ledARGB = 0xff00ff00;
        n.ledOnMS = 300;
        n.ledOffMS = 1000;
        n.flags |= Notification.FLAG_SHOW_LIGHTS; 
        

         4、发通知
        // 标示该通知的ID
        int ID = 1;
        // 发出通知
        nm.notify(ID, n);

利用notification和notificationmanager来实现可视化的消息显示。

/Chapter08_Notification1/src/com/amaker/ch08/app/MainActivity.java

package com.amaker.ch08.app;

import com.amaker.ch08.app.R;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

/**
 * 测试通知
 */

public class MainActivity extends Activity {
    // 声明按钮
    private Button sendBtn,cancelBtn;
    // 声明Notification
    private Notification n ;
    // 声明NotificationManager
    private NotificationManager nm;
    // Notification标示ID
    private static final int ID = 1;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        // 实例化按钮
        sendBtn = (Button)findViewById(R.id.sendButton01);
        cancelBtn = (Button)findViewById(R.id.cancelButton02);
        
        // 获得NotificationManager实例
        String service = NOTIFICATION_SERVICE;
        nm = (NotificationManager)getSystemService(service);
        
        // 实例化Notification
        n = new Notification();
        // 设置显示图标，该图标会在状态栏显示
        int icon = n.icon = R.drawable.happy; 
        // 设置显示提示信息，该信息也会在状态栏显示
        String tickerText = "Test Notification"; 
        // 显示时间
        long when = System.currentTimeMillis();
        n.icon = icon;
        n.tickerText = tickerText;
        n.when = when;
        // 为按钮添加监听器
        sendBtn.setOnClickListener(sendListener);
        cancelBtn.setOnClickListener(cancelListener);
        
    }
    // 发送通知监听器
    private OnClickListener sendListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            // 实例化Intent
            Intent intent = new Intent(MainActivity.this, MainActivity.class); 
            // 获得PendingIntent
            PendingIntent pi = PendingIntent.getActivity(MainActivity.this, 0, intent, 0); 
            // 设置事件信息
            n.setLatestEventInfo(MainActivity.this, "My Title", "My Content", pi); 
            // 发出通知
            nm.notify(ID, n);
        }
    };
    // 取消通知监听器
     private OnClickListener cancelListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            // 取消通知
            nm.cancel(ID);
        }
    };
}

/Chapter08_Notification1/res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="测试Notification"
    />
    
<Button 
    android:text="发出通知" 
    android:id="@+id/sendButton01" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"></Button>

<Button 
    android:text="取消通知" 
    android:id="@+id/cancelButton02" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"></Button>

</LinearLayout>

/Chapter08_Notification1/AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.amaker.ch08.app"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <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>

    </application>
    <uses-sdk android:minSdkVersion="3" />

</manifest> 

二、notification、notificationmanager和broadcast receiver的综合实例

/Chapter08_Notification2/src/com/amaker/ch08/app/MainActivity.java

package com.amaker.ch08.app;

import com.amaker.ch08.app.R;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
/**
 * 测试广播和通知
 */
public class MainActivity extends Activity {
    // 声明Button
    private Button btn;
    // 定义Broadcast Receiver action
    private static final String MY_ACTION = "com.amaker.ch08.app.MY_ACTION";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 设置当前布局视图
        setContentView(R.layout.main);
        // 实例化Button
        btn = (Button)findViewById(R.id.Button01);
        // 添加事件监听器
        btn.setOnClickListener(listener);
    }
    // 创建事件监听器
    private OnClickListener listener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            // 实例化Intent
            Intent intent = new Intent();
            // 设置Intent action属性
            intent.setAction(MY_ACTION);
            // 发起广播
            sendBroadcast(intent);
        }
    };
}

/Chapter08_Notification2/src/com/amaker/ch08/app/DisplayActivity.java

package com.amaker.ch08.app;

import com.amaker.ch08.app.R;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class DisplayActivity extends Activity {
    // 声明按钮
    private Button cancelBtn;
    // 声明Notification
    private Notification n ;
    // 声明NotificationManager
    private NotificationManager nm;
    // Notification标示ID
    private static final int ID = 1;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main2);
        // 实例化按钮
        cancelBtn = (Button)findViewById(R.id.cancelButton02);
        // 获得NotificationManager实例
        String service = NOTIFICATION_SERVICE;
        nm = (NotificationManager)getSystemService(service);
        
        // 实例化Notification
        n = new Notification();
        // 设置显示图标，该图标会在状态栏显示
        int icon = n.icon = R.drawable.happy; 
        // 设置显示提示信息，该信息也会在状态栏显示
        String tickerText = "Test Notification"; 
        // 显示时间
        long when = System.currentTimeMillis();
        n.icon = icon;
        n.tickerText = tickerText;
        n.when = when;
        
        // 实例化Intent
        Intent intent = new Intent(this, MainActivity.class); 
        // 获得PendingIntent
        PendingIntent pi = PendingIntent.getActivity(this, 0, intent, 0); 
        // 设置事件信息
        n.setLatestEventInfo(this, "My Title", "My Content", pi); 
        // 发出通知
        nm.notify(ID, n);
        
        // 为按钮添加监听器
        cancelBtn.setOnClickListener(cancelListener);
    }
    
    // 取消通知监听器
     private OnClickListener cancelListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            // 取消通知
            nm.cancel(ID);
        }
    };
}

/Chapter08_Notification2/src/com/amaker/ch08/app/MyReceiver.java

package com.amaker.ch08.app;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class MyReceiver extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        // 实例化Intent
        Intent i = new Intent();
        // 在新的任务中启动Activity
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        // 设置Intent启动的组件名称
        i.setClass(context, DisplayActivity.class);
        // 启动Activity显示通知
        context.startActivity(i);
    }

}

/Chapter08_Notification2/res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

    <Button 
        android:text="发出广播" 
        android:id="@+id/Button01" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"></Button>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.amaker.ch08.app"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <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>
        
        <receiver android:name="MyReceiver">
            <intent-filter>
                <action android:name="com.amaker.ch08.app.MY_ACTION"/>
            </intent-filter>
        </receiver>
        
        <activity android:name="DisplayActivity"/>

    </application>
    <uses-sdk android:minSdkVersion="3" />

</manifest>