如何使用pendingIntent Kotlin从Activity传递到BroadcastReceiver

问题描述

嗨，我正在尝试使用WeatherNotification活动中的值显示来自Weatherbroadcater broadcastReceiver的温度值和天气描述通知。但是，由于在broadcastReceiver上显示为空，因此我无法检索这些值。检查我该怎么做，并先谢谢

WeatherNotification.kt

private fun setIntent() {
    val intent = Intent(this,Weatherbroadcaster::class.java)

    Log.d("broadcast","sending to broadcast Temp: ${weatherResult.temp},Desc: ${weatherResult.weatherDescription}")
    intent.putExtra("Temp",weatherResult.temp.toString())
    intent.putExtra("WeatherDes",weatherResult.weatherDescription.toString())
    val pendingIntent: PendingIntent = PendingIntent.getbroadcast(context,intent,PendingIntent.FLAG_UPDATE_CURRENT)
    alarmManager = getSystemService(Context.ALARM_SERVICE) as AlarmManager

    val timeStart = System.currentTimeMillis()
    val interval = 1000

    alarmManager.setRepeating(
        AlarmManager.RTC_WAKEUP,timeStart,interval.toLong(),pendingIntent
    )
}

Weatherbroadcaster.kt

    override fun onReceive(context: Context?,intent: Intent?) {
    val intent = Intent(context,WeatherNotification::class.java)

    val temp: String? = intent.getStringExtra("Temp")
    val desc: String? = intent.getStringExtra("WeatherDes")
    Log.d("broadcast","sending to broadcast Temp: $temp,Desc: $desc")

    val pendingIntent: PendingIntent = PendingIntent.getActivity(context,0)

    var bitmap = BitmapFactory.decodeResource(context?.resources,R.drawable.pressure)
    var bitmapSun =
        BitmapFactory.decodeResource(context?.resources,R.drawable.sunrise)

    val builder = NotificationCompat.Builder(context!!,CHANNEL_ID)
        .setSmallIcon(R.drawable.ic_launcher_foreground)
        .setContentTitle(temp)
        .setContentText(desc)
        .setLargeIcon(bitmapSun)
        .setStyle(NotificationCompat.BigPictureStyle().bigPicture(bitmap))
        .setContentIntent(pendingIntent)
        .setPriority(NotificationCompat.PRIORITY_DEFAULT)

    with(notificationmanagerCompat.from(context)) {
        notify(notificationId,builder.build())
    }
}

LogCat

2020-10-08 16:56:13.774 6462-18591/com.sgtech.ict3104.racecar D/broadcast: sending to broadcast Temp: 30.97°C,Desc: light rain

2020-10-08 16:56:33.227 6462-6462/com.sgtech.ict3104.racecar D/broadcast: sending to broadcast Temp: null,Desc: null

解决方法

温度键上有错字，您正在初始化接收器上的新意图

override fun onReceive(context: Context?,intent: Intent?) {
    val intent = Intent(context,WeatherNotification::class.java)
    //...
}

val intent是您要从方法签名上的Intent参数创建的新context。您需要检查的是intent参数。

override fun onReceive(context: Context?,intent: Intent?) {
    //the intent is now the same as in the argument,the same received
    intent ?: return
    val temp: String? = intent.getStringExtra("temp")
    val desc: String? = intent.getStringExtra("WeatherDes")
    Log.d("Broadcast","sending to broadcast Temp: $temp,Desc: $desc")
    //...
}