一、概念
Notification，是一种具有全局效果的通知，可以在系统的通知栏中显示。当App向系统发出通知时，它将先以图标的形式显示在通知栏中。用户可以下拉通知栏查看通知的详细信息。通知栏和抽屉式通知栏均是由系统控制，用户可以随时查看。
二、使用
Notification的基本操作主要有创建、更新、取消这三种。
一个 Notification的必要属性有三项，如果不设置则在运行时会抛出异常：
小图标，通过 setSmallIcon() 方法设置；
标题，通过 setContentTitle() 方法设置；
内容，通过 setContentText() 方法设置。
除了以上三项，其它均为可选项。可以给 Notification设置一个 Action ，这样就可以直接跳转到App的某个Activity、启动一个 Service或者发送一个Broadcast。当系统接收到通知时，可以通过震动、响铃、呼吸灯等多种方式进行提醒。
1.创建Notification
import android.support.v4.app.NotificationCompat;
private void testNotification() {
Intent intent = new Intent(this, MainActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
//获取NotificationManager实例
NotificationManager notifyManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
//实例化NotificationCompat.Builde并设置相关属性
NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
//设置小图标
.setSmallIcon(R.mipmap.ic_launcher)
//设置通知标题
.setContentTitle("最简单的Notification")
//设置通知内容
.setContentText("只有小图标、标题、内容")
//设置pendingIntent
.setContentIntent(pendingIntent)
//点击通知后自动清除
.setAutoCancel(true);
//通过builder.build()方法生成Notification对象,并发送通知,id=1
notifyManager.notify(1, builder.build());
}
2.更新Notification
更新通知只需要再次发送相同ID的通知即可，如果之前的通知还未被取消，则会直接更新该通知相关的属性，如果之前的通知已经被取消，则会重新创建一个新通知。
3.取消Notification
取消通知有以下几种方式：
1.点击通知栏的清除按钮，会清除所有可清除的通知；
2.设置了setAutoCancel()或FLAG_AUTO_CANCEL的通知，点击该通知时会清除它；
3.通过NotificationManager调用cancel(int id)方法清除指定ID的通知；
4.通过NotificationManager调用cancel(String tag, int id)方法清除指定TAG和ID的通知；
5.通过NotificationManager调用cancelAll()方法清除所有该应用之前发送的通知。
如果是通过NotificationManager.notify(String tag, int id, Notification notify)方法创建的通知，那么只能通过NotificationManager.cancel(String tag, int id)方法才能清除对应的通知，调用NotificationManager.cancel(int id) 无效。
4.设置Notification的通知效果
Notification有震动、响铃、呼吸灯三种通知效果，可以通过setDefaults(int defualts)方法来设置。Default属性有以下四种，一旦设置了Default效果，自定义的效果就会失效。
默认通知效果：
//<uses-permission android:name="android.permission.VIBRATE" />
Notification.DEFAULT_VIBRATE
//添加系统默认声音效果，设置此值后，调用setSound()设置自定义声音无效
Notification.DEFAULT_SOUND
//添加默认呼吸灯效果，使用时须与Notification.FLAG_SHOW_LIGHTS结合使用，否则无效
Notification.DEFAULT_LIGHTS
//添加上述三种默认提醒效果
Notification.DEFAULT_ALL
常用通知效果：
//三色灯提醒，在使用三色灯提醒时候必须加该标志符
Notification.FLAG_SHOW_LIGHTS
//发起正在运行事件（活动中）
Notification.FLAG_ONGOING_EVENT
//让声音、振动无限循环，直到用户响应（取消或者打开）
Notification.FLAG_INSISTENT
//发起Notification后，铃声和震动均只执行一次
Notification.FLAG_ONLY_ALERT_ONCE
//用户单击通知后自动消失
Notification.FLAG_AUTO_CANCEL
//只有调用NotificationManager.cancel()时才会清除
Notification.FLAG_NO_CLEAR
//表示正在运行的服务
Notification.FLAG_FOREGROUND_SERVICE
设置方法：
NotificationCompat.Builder#setDefaults
NotificationCompat.Builder#setSound
NotificationCompat.Builder#setVibrate
NotificationCompat.Builder#setLights
notification.defaults
notification.sound
notification.vibrate
notification.ledARGB
notification.ledOnMS
notification.ledOffMS
notification.flags
三、适配Android 8.0通知
-
AndroidManifest.xml
<receiver android:name=".TestBroadcastReceiver"> <intent-filter> <action android:name="com.tomorrow.intent.action.test"/> </intent-filter> </receiver> -
strings.xml
<string name="one_notification">OneNotification</string> <string name="two_notification">TwoNotification</string> <string name="three_notification">ThreeNotification</string> -
NotificationChannelController
public class NotificationChannelController { public static final String CHANNEL_ID_ONE_NOTIFICATION = "CHANNEL_ID_ONE_NOTIFICATION"; public static final String CHANNEL_ID_TWO_NOTIFICATION = "CHANNEL_ID_TWO_NOTIFICATION"; public static final String CHANNEL_ID_THREE_NOTIFICATION = "CHANNEL_ID_THREE_NOTIFICATION"; @RequiresApi(api = Build.VERSION_CODES.O) private enum Channel { ONE_NOTIFICATION(CHANNEL_ID_ONE_NOTIFICATION, R.string.one_notification, NotificationManager.IMPORTANCE_LOW, true), TWO_NOTIFICATION(CHANNEL_ID_TWO_NOTIFICATION, R.string.two_notification, NotificationManager.IMPORTANCE_DEFAULT, false), THREE_NOTIFICATION(CHANNEL_ID_THREE_NOTIFICATION, R.string.three_notification, NotificationManager.IMPORTANCE_HIGH, true); private final String id; private final int nameResId; private final int importance; private final boolean showBadge; Channel(String id, @StringRes int nameResId, int importance, boolean showBadge) { this.id = id; this.nameResId = nameResId; this.importance = importance; this.showBadge = showBadge; } public String getId() { return id; } public int getNameResId() { return nameResId; } public int getImportance() { return importance; } public boolean canShowBadge() { return showBadge; } } public static void createChannels(Context context) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { final NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE); List<NotificationChannel> channelList = new ArrayList<>(); for (Channel channel : Channel.values()) { NotificationChannel notificationChannel = new NotificationChannel(channel.getId(), context.getString(channel.getNameResId()), channel.getImportance()); notificationChannel.setShowBadge(channel.canShowBadge()); channelList.add(notificationChannel); } if (notificationManager != null) { notificationManager.createNotificationChannels(channelList); } } } } -
MainActivity
import android.app.PendingIntent; import android.content.Intent; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Bundle; import android.support.v4.app.NotificationCompat; import android.support.v4.app.NotificationManagerCompat; import android.support.v7.app.AppCompatActivity; import android.util.Log; public class MainActivity extends AppCompatActivity { private static final String TAG = MainActivity.class.getSimpleName(); private TestBroadcastReceiver mReceiver; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Log.d(TAG, "zwm, onCreate"); //适配Android 8.0, 创建通知渠道 NotificationChannelController.createChannels(getApplicationContext()); Intent intent = new Intent("com.tomorrow.intent.action.test"); intent.setPackage(getPackageName()); PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT); Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher); NotificationCompat.Builder builder = new NotificationCompat.Builder(this, NotificationChannelController.CHANNEL_ID_THREE_NOTIFICATION); builder.setShowWhen(true) .setContentTitle("notification title") .setContentText("notification content") .setLargeIcon(bitmap) .setSmallIcon(R.mipmap.ic_launcher) .setStyle(new NotificationCompat.BigTextStyle().bigText("BigTextStyle content")) .setContentIntent(pendingIntent) .setAutoCancel(true); NotificationManagerCompat.from(this).notify(99, builder.build()); } } -
TestBroadcastReceiver
public class TestBroadcastReceiver extends BroadcastReceiver { private static final String TAG = "TestBroadcastReceiver"; @Override public void onReceive(Context context, Intent intent) { Log.d(TAG, "zwm, onReceive, action: " + intent.getAction()); } } -
打印日志
2020-03-26 13:26:30.397 20445-20445/com.tomorrow.architetest D/MainActivity: zwm, onCreate 2020-03-26 13:26:50.909 20445-20445/com.tomorrow.architetest D/TestBroadcastReceiver: zwm, onReceive, action: com.tomorrow.intent.action.test
