Android通知——Notification

创建通道

在显示通知之前必须先设置通道，这是必须前提。
可以在此对此通道的通知进行基本的设置，例如是否显示呼吸灯、是否震动、优先级等。

代码大概长这样：

/*** 创建通知渠道（8.0后新增,必须）* 应该再应用启动时就自己支持创建渠道，否则收不到通知，可以重复创建*/
private fun createNotificationChannel() {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {val name = "测试通知"val descriptionText = "测试通知的渠道"val importance = NotificationManager.IMPORTANCE_DEFAULTval channel =NotificationChannel(CHANNEL_ID_NOTIFICATION_BASIC, name, importance).apply {description = descriptionTextenableLights(false)enableVibration(false)vibrationPattern = LongArray(0)setSound(null, null)}notificationManager.createNotificationChannel(channel)}
}

此操作需要在显示通知前完成，可以重复调用。
创建完通道后可以再设置中看到。

CHANNEL_ID_NOTIFICATION_BASIC 是我们自定义的 CHANNEL_ID 后面显示通知的时候会用到

private const val CHANNEL_ID_NOTIFICATION_BASIC = "CHANNEL_ID_NOTIFICATION_BASIC"

在显示通知之前，我们先创建一个NotificationManager

private lateinit var notificationManager: NotificationManagernotificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager

基本样式通知

/*** 显示基本通知*/
private fun showBasicNotification2() {val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("基本通知").setContentText("我是基本通知内容").setPriority(NotificationCompat.PRIORITY_DEFAULT).build()notificationManager.notify(id++, build)
}

可以展开大图的通知

private fun showBigPictureNotification() {val bitmap = BitmapFactory.decodeStream(resources.assets.open("picture.jpg"))val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("可展开大图").setContentText("我是可展开大图的通知").setStyle(NotificationCompat.BigPictureStyle().bigPicture(bitmap)).build()notificationManager.notify(id++, build)
}

可以展开大段文字的通知

private fun showBigTextNotification() {val bitmap = BitmapFactory.decodeStream(resources.assets.open("picture.jpg"))val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("可展开大段文字").setContentText("我是可展开大段文字的通知").setLargeIcon(bitmap).setStyle(NotificationCompat.BigTextStyle().setBigContentTitle("大段文字").bigText("大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字大段文字")).build()notificationManager.notify(id++, build)
}

列表样式的通知

private fun showMessageSnippetNotification() {val bitmap = BitmapFactory.decodeStream(resources.assets.open("picture.jpg"))val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("列表样式的通知").setContentText("我是列表样式的通知").setLargeIcon(bitmap).setStyle(NotificationCompat.InboxStyle().addLine("1111111").addLine("2222222").addLine("3").addLine("444").addLine("555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555").addLine("6666666666666666")).build()notificationManager.notify(id++, build)
}

列表中最多显示6行（addLine 6次），多余6行的内容将无法显示。

对话样式的通知

private fun showMessagingNotification() {val bitmap = BitmapFactory.decodeStream(resources.assets.open("picture.jpg"))val createWithBitmap = IconCompat.createWithBitmap(bitmap)val message1 = NotificationCompat.MessagingStyle.Message("你好啊", System.currentTimeMillis(), Person.Builder().setName("张三").setIcon(createWithBitmap).build())val message2 = NotificationCompat.MessagingStyle.Message("谢谢", System.currentTimeMillis(), Person.Builder().setName("李四").setBot(true).build())val message3 = NotificationCompat.MessagingStyle.Message("Hello!", System.currentTimeMillis(), Person.Builder().setName("王五").setImportant(true).build())val message4 = NotificationCompat.MessagingStyle.Message("Android", System.currentTimeMillis(), Person.Builder().setName("赵六").setIcon(createWithBitmap).build())val message5 = NotificationCompat.MessagingStyle.Message("Notification", System.currentTimeMillis(), Person.Builder().setName("小七").build())val message6 = NotificationCompat.MessagingStyle.Message("biubiubiu~", System.currentTimeMillis(), Person.Builder().setName("老八").build())val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setSmallIcon(R.mipmap.ic_launcher).setLargeIcon(bitmap).setStyle(NotificationCompat.MessagingStyle(Person.Builder().setName("kongqw").build()).addMessage(message1).addMessage(message2).addMessage(message3).addMessage(message4).addMessage(message5).addMessage(message6)).build()notificationManager.notify(id++, build)
}

列表中最多显示5条，后添加的消息会挤掉前面的消息。

媒体控件样式的通知

需要先添加一个依赖

implementation "androidx.media:media:1.1.0"

private fun showMediaNotification() {val bitmap = BitmapFactory.decodeStream(resources.assets.open("picture.jpg"))val pendingIntentPrevious: PendingIntent = PendingIntent.getBroadcast(this, 0, Intent("com.kongqw.notification.media.previous"), 0)val pendingIntentPause: PendingIntent = PendingIntent.getBroadcast(this, 0, Intent("com.kongqw.notification.media.pause"), 0)val pendingIntentNext: PendingIntent = PendingIntent.getBroadcast(this, 0, Intent("com.kongqw.notification.media.next"), 0)val pendingIntentPlay: PendingIntent = PendingIntent.getBroadcast(this, 0, Intent("com.kongqw.notification.media.play"), 0)val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setVisibility(NotificationCompat.VISIBILITY_PUBLIC).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("媒体控件样式通知").setContentText("我是媒体控件样式通知").addAction(android.R.drawable.ic_media_previous, "Previous", pendingIntentPrevious).addAction(android.R.drawable.ic_media_pause, "Pause", pendingIntentPause).addAction(android.R.drawable.ic_media_next, "Next", pendingIntentNext).addAction(android.R.drawable.ic_media_play, "Play", pendingIntentPlay).setLargeIcon(bitmap).setStyle(androidx.media.app.NotificationCompat.MediaStyle().setShowActionsInCompactView(0, 1, 2) // .setMediaSession()).build()notificationManager.notify(id++, build)
}

上述代码中addAction添加了4个控制按钮，setShowActionsInCompactView设置了通知在收起状态下，显示第0、1、2个按钮。

点击通知跳转Activity

在基本样式通知的基础上举例，只需要setContentIntent即可

private fun showBasicNotification3() {// 创建一个跳转的Intentval intent = Intent(this, MainActivity::class.java).apply { // ... 其他一些设置信息}// 创建 PendingIntentval jumpIntent: PendingIntent = PendingIntent.getActivity(this, 0, intent, 0)val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("基本通知").setContentText("我是基本通知内容,点击可以跳转Activity.").setPriority(NotificationCompat.PRIORITY_DEFAULT)// 设置跳转，点击打开MainActivity.setContentIntent(jumpIntent).build()notificationManager.notify(id++, build)
}

添加Action

同样在基本样式通知的基础上举例，Action可以添加点击跳转行为，也可以添加点击发送广播的行为。

private fun showBasicNotification4() {// 创建一个跳转的Intentval intent = Intent(this, MainActivity::class.java).apply {// ... 其他一些设置信息}// 创建 PendingIntentval jumpIntent: PendingIntent = PendingIntent.getActivity(this, 0, intent, 0)// 创建发送广播的Intentval sendBroadcastIntent: PendingIntent = PendingIntent.getBroadcast(this, 0, Intent("com.kongqw.notificationsimple.action"), 0)val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setSmallIcon(R.mipmap.ic_launcher).setContentTitle("基本通知").setContentText("我是带有Action的基本通知内容").setPriority(NotificationCompat.PRIORITY_DEFAULT)// 设置点击跳转的Action.addAction(R.mipmap.ic_launcher, "点我打开MainActivity", jumpIntent)// 设置点击发送广播的Action.addAction(R.mipmap.ic_launcher, "点我发送一条广播", sendBroadcastIntent).build()notificationManager.notify(id++, build)
}

jumpIntent 设置了点击跳转到MainActivity
sendBroadcastIntent 设置了发送广播的内容，动态注册一个广播后自行验证即可。

在通知中直接回复

private fun showReplayNotification() {// 设置回复后的广播val replyPendingIntent: PendingIntent = PendingIntent.getBroadcast(applicationContext, 0, Intent("com.kongqw.notificationsimple.reply"), PendingIntent.FLAG_UPDATE_CURRENT)// 设置回复输入框val remoteInput: RemoteInput = RemoteInput.Builder("KEY_TEXT_REPLY").setLabel("请输入").build()// 设置回复按钮val replyAction = NotificationCompat.Action.Builder(R.drawable.ic_launcher_background, "回复", replyPendingIntent).addRemoteInput(remoteInput).build()// 模拟收到的消息val bitmap = BitmapFactory.decodeStream(resources.assets.open("picture.jpg"))val message = NotificationCompat.MessagingStyle.Message("你好啊", System.currentTimeMillis(), Person.Builder().setName("张三").setIcon(IconCompat.createWithBitmap(bitmap)).build())val build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_BASIC).setSmallIcon(R.mipmap.ic_launcher).setPriority(NotificationCompat.PRIORITY_DEFAULT).setStyle(NotificationCompat.MessagingStyle(Person.Builder().setName("kongqw").build()).addMessage(message))// 回复.addAction(replyAction).build()notificationManager.notify(id++, build)
}

KEY_TEXT_REPLY 用来标记回复的文字内容，在广播接收者中使用该字段来获取回复的文字

广播接收（代码仅供参考，注册广播请自行处理）

inner class MyBroadcastReceiver : BroadcastReceiver() {override fun onReceive(context: Context?, intent: Intent?) {when (intent?.action) {"com.kongqw.notificationsimple.action" -> Toast.makeText(applicationContext, "收到广播", Toast.LENGTH_SHORT).show()"com.kongqw.notificationsimple.reply" -> {val charSequence = RemoteInput.getResultsFromIntent(intent)?.getCharSequence("KEY_TEXT_REPLY")Toast.makeText(applicationContext, "回复:$charSequence", Toast.LENGTH_SHORT).show()}}}
}

自定义样式的通知

最后部分，我们来模拟网易云音乐，实现一个自定义的通知样式（仅实现基础样式、不包含功能），先看图（上：网易云音乐，下：自定义）

因为网易云音乐的通知有一些设置，例如：不能滑动删除、静音、没有震动等，所以我们重新创建一个通道，专门来显示我们的自定义通知。

private fun createNotificationChannel2() {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {val name = "播放器"val descriptionText = "模仿网易云音乐的通知"val importance = NotificationManager.IMPORTANCE_DEFAULTval channel =NotificationChannel(CHANNEL_ID_NOTIFICATION_CUSTOM_MEDIA, name, importance).apply {description = descriptionText// 禁用呼吸灯enableLights(false)// 禁止震动enableVibration(false)vibrationPattern = LongArray(0)// 静音setSound(null, null)}notificationManager.createNotificationChannel(channel)}
}

直接上代码部分

private fun showCustomNotification() {// 自定义的通知页面val remoteViewsMedia = RemoteViews(packageName, R.layout.custom_notification_media)// 设置通知页面上按钮的点击广播remoteViewsMedia.setOnClickPendingIntent(R.id.ib_close, PendingIntent.getBroadcast(applicationContext, 0, Intent("com.kongqw.notification.custom.media.close"), 0))remoteViewsMedia.setOnClickPendingIntent(R.id.ib_1, PendingIntent.getBroadcast(applicationContext, 0, Intent("com.kongqw.notification.custom.media.btn1"), 0))remoteViewsMedia.setOnClickPendingIntent(R.id.ib_2, PendingIntent.getBroadcast(applicationContext, 0, Intent("com.kongqw.notification.custom.media.btn2"), 0))remoteViewsMedia.setOnClickPendingIntent(R.id.ib_3, PendingIntent.getBroadcast(applicationContext, 0, Intent("com.kongqw.notification.custom.media.btn3"), 0))remoteViewsMedia.setOnClickPendingIntent(R.id.ib_4, PendingIntent.getBroadcast(applicationContext, 0, Intent("com.kongqw.notification.custom.media.btn4"), 0))remoteViewsMedia.setOnClickPendingIntent(R.id.ib_5, PendingIntent.getBroadcast(applicationContext, 0, Intent("com.kongqw.notification.custom.media.btn5"), 0))// 设置封面remoteViewsMedia.setImageViewBitmap(R.id.iv_cover, BitmapFactory.decodeStream(resources.assets.open("picture.jpg")))build = NotificationCompat.Builder(this, CHANNEL_ID_NOTIFICATION_CUSTOM_MEDIA).setSmallIcon(R.mipmap.ic_launcher)// .setStyle(NotificationCompat.DecoratedCustomViewStyle()).setCustomContentView(remoteViewsMedia).setAutoCancel(false)// 禁止滑动删除.setOngoing(true)build?.priority = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {NotificationManager.IMPORTANCE_MAX} else {NotificationCompat.PRIORITY_MAX}notificationManager.notify(66, build?.build())
}

自定义通知，最核心的的部分就在setCustomContentView,添加了一个自定义的View，这里是一个RemoteViews，因此想到之前的Widget开发，通知的自定义布局和Widget的自定义布局一样，能且仅能使用部分布局和组件，详见Widget。

这里在复述一遍，
可使用的布局包括：

FrameLayout
LinearLayout
RelativeLayout
GridLayout

可使用的控件包括：

AnalogClock
Button
Chronometer
ImageButton
ImageView
ProgressBar
TextView
ViewFlipper
ListView
GridView
StackView
AdapterViewFlipper

注：如果使用除此之外的布局或控件，通知将无法显示。

布局文件 custom_notification_media.xml 提供一下仅供参考

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"android:layout_width="match_parent"android:layout_height="113dp"android:orientation="horizontal"><ImageViewandroid:id="@+id/iv_cover"android:layout_width="113dp"android:layout_height="113dp"android:background="@drawable/ic_launcher_background"android:scaleType="centerCrop" /><LinearLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"android:weightSum="10"><RelativeLayoutandroid:layout_width="match_parent"android:layout_height="60dp"><ImageButtonandroid:id="@+id/ib_close"android:layout_width="30dp"android:layout_height="30dp"android:layout_alignParentEnd="true"android:layout_alignParentRight="true"android:background="@android:color/transparent"android:src="@android:drawable/ic_menu_close_clear_cancel" /><TextViewandroid:id="@+id/tv_title"android:layout_width="match_parent"android:layout_height="35dp"android:layout_toStartOf="@id/ib_close"android:layout_toLeftOf="@id/ib_close"android:gravity="center_vertical"android:paddingStart="10dp"android:paddingEnd="10dp"android:text="我是歌名"android:textColor="#555555"android:textSize="15sp" /><TextViewandroid:id="@+id/tv_des"android:layout_width="match_parent"android:layout_height="match_parent"android:layout_below="@id/tv_title"android:layout_toStartOf="@id/ib_close"android:layout_toLeftOf="@id/ib_close"android:gravity="center_vertical"android:paddingStart="10dp"android:paddingEnd="10dp"android:text="我是歌手名"android:textColor="#AAAAAA"android:textSize="13sp" /></RelativeLayout><TextViewandroid:layout_width="match_parent"android:layout_height="1dp"android:background="#EEEEEE" /><LinearLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:orientation="horizontal"android:weightSum="5"><ImageButtonandroid:id="@+id/ib_1"android:layout_width="0dp"android:layout_height="match_parent"android:layout_weight="1"android:background="@android:color/transparent"android:src="@android:drawable/star_off" /><ImageButtonandroid:id="@+id/ib_2"android:layout_width="0dp"android:layout_height="match_parent"android:layout_weight="1"android:background="@android:color/transparent"android:src="@android:drawable/ic_media_previous" /><ImageButtonandroid:id="@+id/ib_3"android:layout_width="0dp"android:layout_height="match_parent"android:layout_weight="1"android:background="@android:color/transparent"android:src="@android:drawable/ic_media_play" /><ImageButtonandroid:id="@+id/ib_4"android:layout_width="0dp"android:layout_height="match_parent"android:layout_weight="1"android:background="@android:color/transparent"android:src="@android:drawable/ic_media_next" /><ImageButtonandroid:id="@+id/ib_5"android:layout_width="0dp"android:layout_height="match_parent"android:layout_weight="1"android:background="@android:color/transparent"android:src="@android:drawable/ic_lock_power_off" /></LinearLayout></LinearLayout>
</LinearLayout>

广播的注册

private val mMyBroadcastReceiver = MyBroadcastReceiver()
private val mIntentFilter = IntentFilter().apply {addAction("com.kongqw.notification.custom.media.close")addAction("com.kongqw.notification.custom.media.btn1")addAction("com.kongqw.notification.custom.media.btn2")addAction("com.kongqw.notification.custom.media.btn3")addAction("com.kongqw.notification.custom.media.btn4")addAction("com.kongqw.notification.custom.media.btn5")
}

registerReceiver(mMyBroadcastReceiver, mIntentFilter)

反注册

unregisterReceiver(mMyBroadcastReceiver)

广播接收者

inner class MyBroadcastReceiver : BroadcastReceiver() {override fun onReceive(context: Context?, intent: Intent?) {when (intent?.action) {"com.kongqw.notification.custom.media.close" -> {Toast.makeText(applicationContext, "关闭", Toast.LENGTH_SHORT).show()notificationManager.cancel(66)}"com.kongqw.notification.custom.media.btn1" -> Toast.makeText(applicationContext, "按钮1", Toast.LENGTH_SHORT).show()"com.kongqw.notification.custom.media.btn2" -> Toast.makeText(applicationContext, "按钮2", Toast.LENGTH_SHORT).show()"com.kongqw.notification.custom.media.btn3" -> {Toast.makeText(applicationContext, "按钮3", Toast.LENGTH_SHORT).show()val remoteViewsMedia = RemoteViews(packageName, R.layout.custom_notification_media)if (isPlaying) {isPlaying = falseremoteViewsMedia.setImageViewResource(R.id.ib_3, android.R.drawable.ic_media_play)} else {isPlaying = trueremoteViewsMedia.setImageViewResource(R.id.ib_3, android.R.drawable.ic_media_pause)}build?.setCustomContentView(remoteViewsMedia)// 更新通知notificationManager.notify(66, build?.build())}"com.kongqw.notification.custom.media.btn4" -> Toast.makeText(applicationContext, "按钮4", Toast.LENGTH_SHORT).show()"com.kongqw.notification.custom.media.btn5" -> Toast.makeText(applicationContext, "按钮5", Toast.LENGTH_SHORT).show()}}
}