一般当我们收到短信啊，微信啊，或者有些app的提醒。我们都会在通知栏收到一天简单的消息，然后点击消息进入到app里面，事实上android中有专门的Notification的类能够完毕这个工作，这里就实现下这个功能。

首先新建NotificationTestproject，然后加入一个button，用来触发通知。然后编写代码例如以下：

package com.example.jared.notificationtest;import android.app.NotificationManager;
import android.os.Bundle;
import android.support.v4.app.NotificationCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;public class MainActivity extends AppCompatActivity {private Button sendNotificationBtn;private int mId = 1;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sendNotificationBtn = (Button)findViewById(R.id.sendNotification);sendNotificationBtn.setOnClickListener(new myOnClickListener());}private class myOnClickListener implements View.OnClickListener {@Overridepublic void onClick(View view) {switch (view.getId()) {case R.id.sendNotification:setSendNotificationBtn();break;default:break;}}}public void setSendNotificationBtn () {NotificationCompat.Builder notification = new NotificationCompat.Builder(this).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("My Notification").setContentText("Hello Notification");NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);manager.notify(mId, notification.build());}
}

这里了用了NotificatonCompat.Builder来创建一个简单的Notification，setSmallIcon是指定当中的图标，setContentTitle方法是指定标题，setContentText指定内容，然后通过getSystemService获取通知的管理类，通过notify方法发送通知，当中mId是一个id号，每个通知有其独特的通知号。不能反复。

执行效果例如以下所看到的：

接着我们来实现点击通知后跳转到相应的Activity中，然后消除这条通知。再创建一个Activity，布局例如以下：

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

> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.jared.notificationtest.Notification"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="欢迎点击通知事件!" android:layout_margin="20dp" android:textSize="20dp"/> </LinearLayout>

这里就一个textview用来显示下信息，接着编写代码例如以下：

package com.example.jared.notificationtest;import android.app.NotificationManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;public class Notification extends AppCompatActivity {private int mId = 1;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_notification);NotificationManager manager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);manager.cancel(mId);}
}

这里进入到Activity后就把通知清除掉，接着就是改动MainActivity代码：

package com.example.jared.notificationtest;import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.NotificationCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;public class MainActivity extends AppCompatActivity {private Button sendNotificationBtn;private int mId = 1;private int numMessage = 0;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sendNotificationBtn = (Button)findViewById(R.id.sendNotification);sendNotificationBtn.setOnClickListener(new myOnClickListener());}private class myOnClickListener implements View.OnClickListener {@Overridepublic void onClick(View view) {switch (view.getId()) {case R.id.sendNotification:setSendNotificationBtn();break;default:break;}}}public void setSendNotificationBtn () {NotificationCompat.Builder notification = new NotificationCompat.Builder(this).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("My Notification").setContentText("Hello Notification").setNumber(++numMessage);Intent intent = new Intent(this, Notification.class);PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent,PendingIntent.FLAG_CANCEL_CURRENT);notification.setContentIntent(pendingIntent);NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);manager.notify(mId, notification.build());}
}

这里又加入了setNumber方法。主要是显示来了几条通知，比方微信中就须要知道，然后实例化了一个intent。再实例化一个pendingIntent。获取activity，在NotificationCompat.Builder里setContentIntent。之后就能够达到我们的效果，执行并点击通知例如以下所看到的：

如上所看到的收到了6条通知，然后点击后通知也消除了。

一般在下载歌曲啊。图片啊的时候。会有进度条表示下载的过程，这里来模拟实现下这个功能。改动MainAcitivy代码例如以下：

package com.example.jared.notificationtest;import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.NotificationCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;public class MainActivity extends AppCompatActivity {private static final String TAG = "MainActivity";private Button sendNotificationBtn;private int mId = 1;private int numMessage = 0;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sendNotificationBtn = (Button)findViewById(R.id.sendNotification);sendNotificationBtn.setOnClickListener(new myOnClickListener());}private class myOnClickListener implements View.OnClickListener {@Overridepublic void onClick(View view) {switch (view.getId()) {case R.id.sendNotification:setSendNotificationBtn();break;default:break;}}}public void setSendNotificationBtn () {final NotificationCompat.Builder notification = new NotificationCompat.Builder(this).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("Music Download").setContentText("burning.mp3").setNumber(++numMessage);Intent intent = new Intent(this, Notification.class);PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent,PendingIntent.FLAG_CANCEL_CURRENT);notification.setContentIntent(pendingIntent);final NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);new Thread(new Runnable(){@Overridepublic void run() {for(int cnt=0; cnt<=100; cnt++){notification.setProgress(100, cnt, false);manager.notify(mId, notification.build());try {Thread.sleep(200);} catch (InterruptedException e) {Log.d(TAG, "Sleep failure");}}notification.setContentText("Download complete");notification.setProgress(0, 0, false);manager.notify(mId, notification.build());}}).start();}
}

这里通过setProgress方法来实现，这里开了一个Thread，当下载完毕后又一次设置下内容。

执行结果例如以下：

图1显示运行进度条在走，图2完毕了下载功能。

一般收到通知，手机都会有一段声音。加上震动。那么接下来来实现这个功能。上图，假设下载完毕后，就放一段音乐而且震动，改动代码例如以下：

package com.example.jared.notificationtest;import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.NotificationCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;import java.io.File;public class MainActivity extends AppCompatActivity {private static final String TAG = "MainActivity";private Button sendNotificationBtn;private int mId = 1;private int numMessage = 0;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sendNotificationBtn = (Button)findViewById(R.id.sendNotification);sendNotificationBtn.setOnClickListener(new myOnClickListener());}private class myOnClickListener implements View.OnClickListener {@Overridepublic void onClick(View view) {switch (view.getId()) {case R.id.sendNotification:setSendNotificationBtn();break;default:break;}}}public void setSendNotificationBtn () {final NotificationCompat.Builder notification = new NotificationCompat.Builder(this).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("Music Download").setContentText("burning.mp3").setNumber(++numMessage);Intent intent = new Intent(this, Notification.class);PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent,PendingIntent.FLAG_CANCEL_CURRENT);notification.setContentIntent(pendingIntent);final NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);new Thread(new Runnable(){@Overridepublic void run() {for(int cnt=0; cnt<=100; cnt++){notification.setProgress(100, cnt, false);manager.notify(mId, notification.build());try {Thread.sleep(100);} catch (InterruptedException e) {Log.d(TAG, "Sleep failure");}}notification.setContentText("Download complete");notification.setProgress(0, 0, false);Uri soundUri = Uri.fromFile(new File("/system/media/audio/animationsounds/bootSound.ogg"));notification.setSound(soundUri);long[] vibrates = {0, 1000, 1000, 1000};notification.setVibrate(vibrates);manager.notify(mId, notification.build());}}).start();}
}

这里加上了setSound和setVibrate方法，而且须要在AndroidManifest中加入权限：

<uses-permission android:name="android.permission.VIBRATE"/>

这里的歌曲名是通过adb shell查看系统的存在的音乐：

下载到手机执行后就能够观察效果。

当然还能够控制led灯，不知为啥led灯的效果一直没有，网上翻阅非常多资料也没找到问题所在，若有朋友知道。麻烦告知一二不甚感激。

 notification.setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION));long[] vibrates = {0, 1000, 1000, 1000};notification.setVibrate(vibrates);notification.setLights(Color.GREEN, 1000, 1000);

关于Notification基本上就学到这里了。