Firebase:如何在Android应用中设置默认通知频道？

Question

如何为应用程序在后台时出现的通知消息设置默认通知通道？默认情况下,这些消息使用"杂项"通道.

Answer 1

正如您在官方文档中所看到的,您需要AndroidManifest.xml在应用程序组件中添加以下元数据元素:

<meta-data
    android:name="com.google.firebase.messaging.default_notification_channel_id"
    android:value="@string/default_notification_channel_id"/>

当通知消息没有指定频道,或者应用程序尚未创建提供的频道时,将使用此默认频道.

Answer 2

您需要使用 注册频道NotificationManager CreateNotificationChannel。

此示例在 Xamarin 中使用 c#，但广泛适用于其他地方

private void ConfigureNotificationChannel()
{
    if (Build.VERSION.SdkInt < BuildVersionCodes.O)
    {
        // Notification channels are new in API 26 (and not a part of the
        // support library). There is no need to create a notification
        // channel on older versions of Android.
        return;
    }

    var channelId = Resources.GetString(Resource.String.default_notification_channel_id);
    var channelName = "Urgent";
    var importance = NotificationImportance.High;

    //This is the default channel and also appears in the manifest
    var chan = new NotificationChannel(channelId, channelName, importance);

    chan.EnableVibration(true);
    chan.LockscreenVisibility = NotificationVisibility.Public;

    var notificationManager = (NotificationManager)GetSystemService(NotificationService);
    notificationManager.CreateNotificationChannel(chan);

}

该渠道应该是唯一的，例如com.mycompany.myapp.urgent

然后，您可以在AndroidManifest.xml的应用程序标记内添加对字符串的引用

<application android:label="MyApp" android:icon="@mipmap/icon">
    <meta-data android:name="com.google.firebase.messaging.default_notification_channel_id" android:value="@string/default_notification_channel_id" />
</application>

最后，在strings.xml中设置字符串

<?xml version="1.0" encoding="UTF-8" ?>
<resources>
    <string name="default_notification_channel_id">com.mycompany.myapp.urgent</string>
</resources>