Android開發教程：Notification和NotificationManager淺析

Notification和NotificationManager操作相對比較簡單，一般獲取系統級的服務NotificationManager，然後實例化Notification，設置它的屬性，通過NotificationManager發出通知就可以了。基本步驟如下：

1.獲取NotificationManager

String service = Context.NOTIFICATION_SERVICE;

NotificationManager mNotificationManager =(NotificationManager)getSystemService(service);

2.實例化Notification對象

//實例化Notification  
Notification notification = new Notification(); 

3.設置Notification的屬性

// 設置顯示圖標，該圖標會在狀態欄顯示    
int icon = notification.icon = R.drawable.happy;    
// 設置顯示提示信息，該信息也在狀態欄顯示   
String tickerText = "測試Notification";     
// 顯示時間    
long when = System.currentTimeMillis();  notification.icon = icon;    
notification.tickerText = tickerText;    
notification.when = when;    
 
//也可以這樣設置    
Notification notification_2=new Notification(icon,tickerText,when)  

調用setLatestEventInfo()方法在視圖中設置圖標和時間。

// 實例化Intent  
Intent intent = new Intent(MainActivity.this, MainActivity.class);   
// 獲得PendingIntent  
PendingIntent pIntent = PendingIntent.getActivity(MainActivity.this, 0, intent, 0);   
// 設置事件信息  
notification.setLatestEventInfo(MainActivity.this, " Title", "Content", pIntent);  

4.發出通知

//Notification標示ID  
private static final int ID = 1;  
//發出通知  
mNotificationManager.notify(ID, n); 

下面是具體的例子,在這個例子裡定義了一個MainActivity發出廣播通知，定義一個MyReceiver類繼承Broadcasts接受通知，當接收完通知之後，啟動一個SecondActivity，在SecondActivity類中通過Notification和NotificationManager來可視化顯示廣播通知。具體的步驟如下：

MainActivity.java

package com.Android.notification;  
 
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;  
 
public class MainActivity extends Activity {  
    // 聲明Button  
    private Button btn;  
    // 定義Broadcast Receiver action  
    private static final String MY_ACTION = "com.android.notification.MY_ACTION";  
    @Override 
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        // 設置當前布局視圖  
        setContentView(R.layout.main);  
        // 實例化Button  
        btn = (Button)findViewById(R.id.Button1);  
        // 添加事件監聽器  
        btn.setOnClickListener(listener);  
    }  
    // 創建事件監聽器  
    private OnClickListener listener = new OnClickListener() {  
        @Override 
        public void onClick(View v) {  
            // 實例化Intent  
            Intent intent = new Intent();  
            // 設置Intent action屬性  
            intent.setAction(MY_ACTION);  
            // 發起廣播  
            sendBroadcast(intent);  
        }  
    };  
} 

MyReceiver.java

package com.android.notification;  
 
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) {  
        // 實例化Intent  
        Intent i = new Intent();  
        // 在新的任務中啟動Activity  
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  
        // 設置Intent啟動的組件名稱  
        i.setClass(context, SecondActivity.class);  
        // 啟動Activity顯示通知  
        context.startActivity(i);  
    }  
}  

SecondActivity.java

package com.android.notification;  
 
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 SecondActivity extends Activity {  
    // 聲明按鈕  
    private Button cancelBtn;  
    // 聲明Notification  
    private Notification notification ;  
    // 聲明NotificationManager  
    private NotificationManager mNotification;  
    // Notification標示ID  
    private static final int ID = 1;  
    @Override 
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.second);  
        // 實例化按鈕  
        cancelBtn = (Button)findViewById(R.id.cancelButton2);  
        // 獲得NotificationManager實例  
        String service = NOTIFICATION_SERVICE;  
        mNotification = (NotificationManager)getSystemService(service);  
          
        // 實例化Notification  
        notification = new Notification();  
        // 設置顯示圖標，該圖標會在狀態欄顯示  
        int icon = notification.icon = android.R.drawable.stat_notify_chat;   
        // 設置顯示提示信息，該信息也會在狀態欄顯示  
        String tickerText = "Test Notification";   
        // 顯示時間  
        long when = System.currentTimeMillis();  
        notification.icon = icon;  
        notification.tickerText = tickerText;  
        notification.when = when;  
          
        // 實例化Intent  
        Intent intent = new Intent(this, MainActivity.class);   
        // 獲得PendingIntent  
        PendingIntent pi = PendingIntent.getActivity(this, 0, intent, 0);   
        // 設置事件信息  
        notification.setLatestEventInfo(this, "消息", "Hello Android", pi);   
        // 發出通知  
        mNotification.notify(ID, notification);  
          
        // 為按鈕添加監聽器  
        cancelBtn.setOnClickListener(cancelListener);  
    }  
      
    // 取消通知監聽器  
     private OnClickListener cancelListener = new OnClickListener() {  
        @Override 
        public void onClick(View v) {  
            // 取消通知  
            mNotification.cancel(ID);  
        }  
    };  
}