注册NotificationChannel

    private const val channelIdNormal = "ktools_channel_normal"

    /**
     * 应用启动时调用
     */
    fun createNotificationChannel(context: Context){
        val channel = NotificationChannel(channelIdNormal,  channelIdNormal,NotificationManager.IMPORTANCE_HIGH).apply {
            description = "应用中的普通通知"
        }
        context.notificationManager.createNotificationChannel(channel)
    }

点击动作

PendingIntent.getActivity()
PendingIntent.getService()
PendingIntent.getBroadcast()
PendingIntent.getActivities()
PendingIntent.getForegroundService()

显示/更新通知

context.notificationManager.notify(id, notification)

移除通知

• 用户关闭通知。

• 用户点击通知，且您在创建通知时调用了 setAutoCancel()。

• 您针对特定的通知 ID 调用了 cancel()。此方法还会删除当前通知。

• 您调用了 cancelAll() 方法，该方法将移除之前发出的所有通知。

• 如果您在创建通知时使用 setTimeoutAfter() 设置了超时，系统会在指定持续时间过后取消通知。如果需要，您可以在指定的超时持续时间过去之前取消通知。

勿扰模式与通知类别

notification.setCategory(NotificationCompat.CATEGORY_MESSAGE)

通知的样式

• 普通的通知

    fun createNotification(context: Context, @DrawableRes smallIconID: Int, title: String, content: String, intent: Intent): Int {
        val pendingIntent = PendingIntent.getActivity(context, requestCode, intent, PendingIntent.FLAG_UPDATE_CURRENT)
        val notification = NotificationCompat.Builder(context, channelIdNormal)
                .setContentTitle(title)
                .setContentText(content)
                .setSmallIcon(smallIconID)
                .setContentIntent(pendingIntent)
                .setPriority(NotificationCompat.PRIORITY_DEFAULT)
                .addAction(android.R.drawable.ic_btn_speak_now,"Voice",pendingIntent)
                .build()
        val id = Random(System.currentTimeMillis()).nextInt()
        context.notificationManager.notify(id, notification)
        return id
    }

• 带进度条

notification.setProgress(0,0,true)

最后一个参数表示是否未具体的进度和无限循环的样式.

• 应用图标上的红点通知

notification.setShowBadge(true)

• 可展开的通知
• 大图

notification.setStyle(NotificationCompat.BigPictureStyle()
                    .bigPicture(myBitmap))

• 大段文本

notification.setStyle(NotificationCompat.BigTextStyle()
                    .bigText(emailObject.getSubjectAndSnippet()))

• 收件箱样式

notification.setStyle(NotificationCompat.InboxStyle()
                    .addLine(messageSnippet1)
                    .addLine(messageSnippet2))

• 对话框样式

    var message1 = NotificationCompat.MessagingStyle.Message(messages[0].getText(),
            messages[0].getTime(),
            messages[0].getSender())
    var message2 = NotificationCompat.MessagingStyle.Message(messages[1].getText(),
            messages[1].getTime(),
            messages[1].getSender())
    var notification = NotificationCompat.Builder(context, CHANNEL_ID)
            .setSmallIcon(R.drawable.new_message)
            .setStyle(NotificationCompat.MessagingStyle(resources.getString(R.string.reply_name))
                    .addMessage(message1)
                    .addMessage(message2))
            .build()

• 媒体类型样式

    import android.support.v4.app.NotificationCompat
    import android.support.v4.media.app.NotificationCompat as MediaNotificationCompat

    var notification = NotificationCompat.Builder(context, CHANNEL_ID)
            // Show controls on lock screen even when user hides sensitive content.
            .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
            .setSmallIcon(R.drawable.ic_stat_player)
            // Add media control buttons that invoke intents in your media service
            .addAction(R.drawable.ic_prev, "Previous", prevPendingIntent) // #0
            .addAction(R.drawable.ic_pause, "Pause", pausePendingIntent) // #1
            .addAction(R.drawable.ic_next, "Next", nextPendingIntent) // #2
            // Apply the media style template
            .setStyle(MediaNotificationCompat.MediaStyle()
                    .setShowActionsInCompactView(1 /* #1: pause button \\*/)
                    .setMediaSession(mediaSession.getSessionToken()))
            .setContentTitle("Wonderful music")
            .setContentText("My Awesome Band")
            .setLargeIcon(albumArtBitmap)
            .build()

• 自定义布局
• 直接使用setCustomBigContentView,但是不使用setStyle
• 使用setStyle + RemoteView:

    // Get the layouts to use in the custom notification
    val notificationLayout = RemoteViews(packageName, R.layout.notification_small)
    val notificationLayoutExpanded = RemoteViews(packageName, R.layout.notification_large)

    // Apply the layouts to the notification
    val customNotification = NotificationCompat.Builder(context, CHANNEL_ID)
            .setSmallIcon(R.drawable.notification_icon)
            .setStyle(NotificationCompat.DecoratedCustomViewStyle())
            .setCustomContentView(notificationLayout)
            .setCustomBigContentView(notificationLayoutExpanded)
            .build()

打开通知设置页

    val intent = Intent(Settings.ACTION_CHANNEL_NOTIFICATION_SETTINGS).apply {
        putExtra(Settings.EXTRA_APP_PACKAGE, packageName)
        putExtra(Settings.EXTRA_CHANNEL_ID, myNotificationChannel.getId())
    }
    startActivity(intent)

参考文档

1. https://developer.android.com/guide/topics/ui/notifiers/notifications?hl=zh-cn

2. https://developer.android.com/training/notify-user/expanded?hl=zh-cn