Android 通知未顯示

Question

測試通知未顯示。 使用 Android 工作室和 Kotlin。

class MainActivity : AppCompatActivity() {
    companion object {
        const val NOTIFICATION_ID = 101
        const val CHANNEL_ID = "channelID"
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val button : Button = findViewById(R.id.button_notification)
        button.setOnClickListener {
            val builder = NotificationCompat.Builder(this, CHANNEL_ID)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle("Notification")
                .setContentText("Go ahead")
                .setPriority(Notification.PRIORITY_HIGH)
                .setAutoCancel(true)

            val notificationManager = NotificationManagerCompat.from(this)
            notificationManager.notify(NOTIFICATION_ID, builder.build())
        }

    }
}

build.gradle（模塊級別）

....
dependencies {

    implementation 'androidx.core:core:1.9.0'
    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.6.0'
    implementation 'com.google.android.material:material:1.7.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
}

當運行應用程序並按下按鈕時 - 沒有任何反應，沒有任何通知。

在模塊級別 build.gradle 中添加了implementation 'androidx.core:core:1.9.0'

Answer 1

從 Android 8.0 開始，你需要創建一個NotificationChannel才能真正從你的 App 發布一個 Notification。 更多細節你可以參考這個。

因為您必須在 Android 8.0 及更高版本上發布任何通知之前創建通知通道，所以您應該在應用啟動后立即執行此代碼。 重復調用此方法是安全的，因為創建現有通知通道不會執行任何操作。

所以，在創建NotificationChannel之前需要添加一個function來創建NotificationChannel：

class MainActivity : Activity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        findViewById<Button>(R.id.btnNotification).setOnClickListener {
            createNotificationChannel()
            
            val builder = NotificationCompat.Builder(this, CHANNEL_ID)
                    .setSmallIcon(R.mipmap.ic_launcher)
                    .setContentTitle("Notification from Test")
                    .setContentText("Test Notification Message received!")
                    .setPriority(NotificationCompat.PRIORITY_DEFAULT)
                    .setAutoCancel(true)

            val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager // NotificationManagerCompat.from(this)
            notificationManager.notify(NOTIFICATION_ID, builder.build())
        }
    }

    private fun createNotificationChannel() {
        // Create the NotificationChannel, but only on API 26+ because
        // the NotificationChannel class is new and not in the support library
        val name = "TestChannel"
        val descriptionText = "TestDescription"
        val importance = NotificationManager.IMPORTANCE_DEFAULT
        val channel = NotificationChannel(CHANNEL_ID, name, importance)
        channel.description = descriptionText
        // Register the channel with the system
        val notificationManager: NotificationManager =
            getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        notificationManager.createNotificationChannel(channel)
    }

    companion object {
        const val NOTIFICATION_ID = 101
        const val CHANNEL_ID = "channelID"
    }
}