在Android 8.1 API 27上,通知不会显示

Question

我在Android 8.1 API 27上获得了Toast:

包"my_package_name"的开发者警告
无法在...上发布通知

Logcat包含下一个字符串:

通知:对于卷控制以外的操作,不推荐使用流类型

W/Notification:请参阅setSound()的文档,了解如何使用android.media.AudioAttributes来限定播放用例

E/NotificationService:找不到pkg = my_package_name的频道

Toast和Logcat中的完整信息可以帮助解决此问题.

Answer 1

如果你得到这个错误应该注意2项并且他们订购:

1. NotificationChannel mChannel = new NotificationChannel(id, name, importance);
2. builder = new NotificationCompat.Builder(context, id);

NotificationManager notifManager和NotificationChannel mChannel也只创建一次.

通知需要设置者:

• builder.setContentTitle()//必需
• .setSmallIcon()//必需
• .setContentText()//必需

见例子:

private NotificationManager notifManager;
public void createNotification(String aMessage, Context context) {
    final int NOTIFY_ID = 0; // ID of notification
    String id = context.getString(R.string.default_notification_channel_id); // default_channel_id
    String title = context.getString(R.string.default_notification_channel_title); // Default Channel
    Intent intent;
    PendingIntent pendingIntent;
    NotificationCompat.Builder builder;
    if (notifManager == null) {
        notifManager = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
    }
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        int importance = NotificationManager.IMPORTANCE_HIGH;
        NotificationChannel mChannel = notifManager.getNotificationChannel(id);
        if (mChannel == null) {
            mChannel = new NotificationChannel(id, title, importance);
            mChannel.enableVibration(true);
            mChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
            notifManager.createNotificationChannel(mChannel);
        }
        builder = new NotificationCompat.Builder(context, id);
        intent = new Intent(context, MainActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
        pendingIntent = PendingIntent.getActivity(context, 0, intent, 0);
        builder.setContentTitle(aMessage)                            // required
               .setSmallIcon(android.R.drawable.ic_popup_reminder)   // required
               .setContentText(context.getString(R.string.app_name)) // required
               .setDefaults(Notification.DEFAULT_ALL)
               .setAutoCancel(true)
               .setContentIntent(pendingIntent)
               .setTicker(aMessage)
               .setVibrate(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
    }
    else {
        builder = new NotificationCompat.Builder(context, id);
        intent = new Intent(context, MainActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
        pendingIntent = PendingIntent.getActivity(context, 0, intent, 0);
        builder.setContentTitle(aMessage)                            // required
               .setSmallIcon(android.R.drawable.ic_popup_reminder)   // required
               .setContentText(context.getString(R.string.app_name)) // required
               .setDefaults(Notification.DEFAULT_ALL)
               .setAutoCancel(true)
               .setContentIntent(pendingIntent)
               .setTicker(aMessage)
               .setVibrate(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400})
               .setPriority(Notification.PRIORITY_HIGH);
    }
    Notification notification = builder.build();
    notifManager.notify(NOTIFY_ID, notification);
}

Answer 2

Andy的回答是有效的,但是我想避免弃用Builder并遵循FireBase Quickstart项目.我刚刚在经理通知之前添加了代码.

String channelId = "default_channel_id";
String channelDescription = "Default Channel";
// Since android Oreo notification channel is needed.
//Check if notification channel exists and if not create one
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
    NotificationChannel notificationChannel = notificationManager.getNotificationChannel(channelId);
    if (notificationChannel == null) {
        int importance = NotificationManager.IMPORTANCE_HIGH; //Set the importance level
        notificationChannel = new NotificationChannel(channelId, channelDescription, importance);
        notificationChannel.setLightColor(Color.GREEN); //Set if it is necesssary
        notificationChannel.enableVibration(true); //Set if it is necesssary
        notificationManager.createNotificationChannel(notificationChannel);
    }
}

//notificationManager.notify as usual

编辑: 他们从示例中删除了通道存在检查我不知道为什么.

Answer 3

我已设置频道ID,但通知仍未显示.

最后我发现我的问题是没有调用"setContentText()"方法.

@Andy Sander提到"必需的安装人员" 真的很有帮助!

这里是Android 8 Oreo API 26及更高版本上Notification的必需设置者:

builder.setContentTitle() // required
.setSmallIcon() // required
.setContentText() // required
.setChannelId(id) // required for deprecated in API level >= 26 constructor .Builder(this)