Android Kotlin:必需的上下文，但找到了字符串

Question

我正在尝试创建一个调度通知的方法。在该方法中，我初始化一个AlarmManager，它将允许我按需接收Intents。然而，我的代码中出现了以下语法错误：

类型不匹配。必需：找到上下文：字符串

在以下行：

var alarmManager = getSystemService(Context.ALARM_SERVICE) as AlarmManager

以下是我的代码：

package com.example.notificationapp
import android.app.AlarmManager
import android.app.NotificationManager
import android.app.PendingIntent
import android.app.PendingIntent.getActivity
import android.content.Context
import android.content.Intent
import androidx.core.app.NotificationCompat
import androidx.core.content.ContextCompat.getSystemService
import java.security.AccessController.getContext
import java.util.*
// Channel
class Notification(context:Context, notificationManager: NotificationManager, title:String, description:String, date: Date) {
// Attributes
private lateinit var context:Context;
private var title:String = ""
private var description:String = ""
private lateinit var date:Date;
private lateinit var notificationManager:NotificationManager;
// Initialization
init {
// Download the constructor parameters into the object's attributes
this.context = context
this.title = title
this.description = description
this.date = date
this.notificationManager = notificationManager
}
// Method to set the notification at a specific time
fun setNotificationAtTime(time:Date) {
var notificationIntent = Intent(this.context, NotificationBroadcast::class.java)
var pendingNotificationIntent = PendingIntent.getBroadcast(this.context,
0, notificationIntent, 0)
// Initialize an AlarmManager that allows us to receive intents on demand
var alarmManager = getSystemService(Context.ALARM_SERVICE) as AlarmManager
val builder = NotificationCompat.Builder(context, "com.example.notificationapp")
}
}

Answer 1

这是因为您使用的是ContextCompat.getSystemService而不是Context.getSystemService。

所以你有两个选择：

1. 使用具有正确签名的ContextCompat.getSystemService：

getSystemService(context, AlarmManager::class.java)

2. 使用Context.getSystemService删除导入语句：

androidx.core.content.ContextCompat.getSystemService

Answer 2

在调用getSystemService((之前添加requireActivity((

val alarmManager = requireActivity().getSystemService(Context.ALARM_SERVICE) as AlarmManager