Android 8.0 Notification和RemoteV

在8.0之后Notification需要适配，不然可能Notification会无法显示，最近在做音乐播放器，用到了Notification和RemoteView，所以把使用记录下来。

RemoteView

RemoteView从名字上看它就是一种远程View，但是它在更新界面时无法象更新Activity那样直接更新View，为了跨进程更新界面，RemoteView提供一系列的setXXX方法去更新View。

PendingIntent

顾名思义，PendingIntent表示一种处于pending状态的Intent，而pending状态表示的是一种待定、等待、即将发生的意思，即有一个Intent将再某个待定时刻发生。PendingIntent和Intent的区别在于PendingIntent是在将来某个不确定的时刻发生的，而Intent则是立刻发生。

PendingIntent支持三种待定Intent

 public static PendingIntent getActivity(Context context, int requestCode,@NonNull Intent intent, @Flags int flags)

获取一个PendingIntent，该待定Intent发生时效果就相当于Content.startActivity(intent)

public static PendingIntent getService(Context context, int requestCode, @NonNull Intent intent, @Flags int flags)

获取一个PendingIntent，该待定Intent发生时效果就相当于Content.startService(intent)

public static PendingIntent getBroadcast(Context context, int requestCode,Intent intent, @Flags int flags)

获取一个PendingIntent，该待定Intent发生时效果就相当于Content.startBroadcast(intent)

PendingIntent的匹配规则

如果两个PendingIntent他们内部的Intent相同并且requestCode也相同，那么这两个PendingIntent也就相同，Intent相同就是CompoentName和intent-filter都相同，那么Intent也就相同。

来看看Notification和RemoteView的使用吧：

object PlayNotification {
private const val NOTIFYCATION_ID = 12323456
private const val CHANNEL_ID = "com.xx.xx.notification.id"
private const val CHANNEL_NAME = "xx"

private var mNotificationManager: NotificationManager? = null

fun show(context: Context?, musicInfo: MusicInfo?, bitmap: Bitmap) {
    if (!NotificationUtil.isNotificationEnable(context)) return
    musicInfo ?: return
    context ?: return

    if (mNotificationManager == null)
        mNotificationManager = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager?

    val pendingIntent = Intent(context, MusicPlayerActivity::class.java).run {
        TaskStackBuilder.create(context)
                .addParentStack(MusicPlayerActivity::class.java)
                .addNextIntent(this)
                .getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT)//flag 只更新data  P
    }

    val customRemoteView = getRemoteView(context, musicInfo, bitmap, R.layout.media_layout_remote_play_cnotify)
    val customRemoteViewBig = getRemoteView(context, musicInfo, bitmap, R.layout.media_layout_remote_play_cnotify_big)

    //8.0+
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        mNotificationManager?.createNotificationChannel(NotificationChannel(CHANNEL_ID, CHANNEL_NAME, NotificationManager.IMPORTANCE_LOW))
    }

    val notification = NotificationCompat.Builder(context, CHANNEL_ID).run {
        setSmallIcon(R.mipmap.media_ic_launcher_round)
        setContentIntent(pendingIntent)//设置跳转页面
        setCustomContentView(customRemoteView)//vivo如果只设置该方法会显示小窗口，需要适配
        setCustomBigContentView(customRemoteViewBig)// 魅族如果只设置大的会不显示通知的内容
        priority = NotificationCompat.PRIORITY_LOW //低于api26 ,设置优先级优先级越大越靠前
        setStyle(android.support.v4.media.app.NotificationCompat.MediaStyle()) // 扩展通知在 Android 4.1 之前的平台上不可用
        setOngoing(true)//禁止侧滑删除
        setAutoCancel(false)//设置点击取消？可点击取消：不可点击取消
        setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
    }.build()

    if (context is Service) {
        context.startForeground(NOTIFYCATION_ID, notification)
    } else {
        mNotificationManager?.notify(NOTIFYCATION_ID, notification)
    }
}

fun dismiss(context: Context?) {
    if (context is Service) context.stopForeground(true)
    mNotificationManager?.cancelAll()
}


/**
 * 需要注意PendingIntent的requestCode，要不然会影响其他点击事件
 */
private fun getRemoteView(context: Context, musicInfo: MusicInfo, bitmap: Bitmap, @LayoutRes id: Int): RemoteViews {
    val playIntent = getPlayPausePendingIntent(context)

    val remoteViews = RemoteViews(context.packageName, id).also {
        it.setTextViewText(R.id.mTvName, musicInfo.musicName)
        it.setTextViewText(R.id.mTvArtist, MusicDataUtils.getSingers(musicInfo) + " - " + musicInfo.albumName)
        it.setImageViewBitmap(R.id.mIvMusicPoster, bitmap)
        it.setImageViewResource(R.id.mIvPlayPause, if (isPlaying()) R.mipmap.media_btn_pause else R.mipmap.media_btn_play_notify)
        it.setOnClickPendingIntent(R.id.mIvPlayPause, playIntent)
    }
    setPendingIntent(remoteViews, R.id.mIvPlayNext, context, 1, VALUE_NEXT)
    setPendingIntent(remoteViews, R.id.mIvPlayPrevious, context, 3, VALUE_PREVIOUS)
    return remoteViews
}

private fun setPendingIntent(remoteViews: RemoteViews, id: Int, context: Context, requestCode: Int, extraValue: String) {
    val pendingIntent = Intent(ACTION).run {
        putExtra(RemoteReceiver.KEY, extraValue)
        PendingIntent.getBroadcast(context, requestCode, this, PendingIntent.FLAG_UPDATE_CURRENT)
    }
    remoteViews.setOnClickPendingIntent(id, pendingIntent)
}

private fun getPlayPausePendingIntent(context: Context): PendingIntent? {
    return Intent(ACTION).run {
        putExtra(RemoteReceiver.KEY, if (isPlaying()) RemoteReceiver.VALUE_PAUSE else RemoteReceiver.VALUE_PLAY)
        PendingIntent.getBroadcast(context, 2, this, PendingIntent.FLAG_UPDATE_CURRENT)
    }
}

private fun isPlaying(): Boolean = MediaServiceManager.service?.isPlaying ?: false


private var mPlayRemoteReceiver: RemoteReceiver? = null
private var mIntentFilter: IntentFilter? = null


/**
 * 注册通知控制广播
 */
fun registerReceiver(context: Context) {
    if (mPlayRemoteReceiver == null) {
        mPlayRemoteReceiver = RemoteReceiver()
    }
    if (mIntentFilter == null) {
        mIntentFilter = IntentFilter(RemoteReceiver.ACTION)
    }
    context.registerReceiver(mPlayRemoteReceiver, mIntentFilter)
}

/**
 * 反注册通知控制广播，可能抛异常
 */
fun unRegisterReceiver(context: Context?) = tryCatch({
    context?.run {
        if (mPlayRemoteReceiver != null) {
            unregisterReceiver(mPlayRemoteReceiver)
            mPlayRemoteReceiver = null
            mIntentFilter = null
        }
    }
})
}

OPPO手机默认会把通知给关闭,需要音带用户开启。