如何在 Android O 中设置 Firebase 通知 ChannelID？

对于 API 级别 26，我们必须设置一个通道 id 作为参考。我学会了如何在没有 ChannelID 的情况下做到这一点，下面是我的 Firebase 消息传递设置代码。但现在对于新的 Android api 26 级别

NotificationCompat.Builder(this);

这不起作用，我应该添加对channelID的引用作为

NotificationCompat.Builder(this, channelID);

但我不知道该怎么做。 您能否帮助我了解如何为 Firebase 云消息传递创建通道 ID？

AndroidManifest.xml

    <service android:name=".MyFirebaseInstanceIdService">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT"></action>
        </intent-filter>
    </service>

    <service android:name=".MyFirebaseMessagingService">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT"></action>
        </intent-filter>
    </service>

MyFirebaseInstanceIdService Java 类：

import android.util.Log;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.FirebaseInstanceIdService;

public class MyFirebaseInstanceIdService extends FirebaseInstanceIdService {

    private static final String REG_TOKEN = "REG_TOKEN";

    @Override
    public void onTokenRefresh() {
        String recent_token = FirebaseInstanceId.getInstance().getToken();
        Log.d(REG_TOKEN, recent_token);
    }
}

MyFirebaseMessagingService Java 类

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.support.v4.app.NotificationCompat;

import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;

public class MyFirebaseMessagingService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {

        Intent intent = new Intent(this, MainActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_ONE_SHOT);

        // Here I will set up a channel ID as "CH_ID_1" but I do not know how to do this.
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, "CH_ID_1");
        //****************************************************

        notificationBuilder.setContentTitle("FCM NOTIFICATION");
        notificationBuilder.setContentText(remoteMessage.getNotification().getBody());
        notificationBuilder.setAutoCancel(true);
        notificationBuilder.setSmallIcon(R.mipmap.ic_launcher);
        notificationBuilder.setContentIntent(pendingIntent);
        NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(0, notificationBuilder.build());

    }
}

Gradle - 依赖项

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.0'
    implementation 'com.android.support:design:26.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.google.firebase:firebase-core:16.0.0'
    implementation 'com.google.firebase:firebase-messaging:17.0.0'
}
apply plugin: 'com.google.gms.google-services'

我之前在应用程序中所做的就是在应用程序启动后立即初始化通知通道。所以我添加了一个init我的应用程序类中的函数，如下所示：

    @TargetApi(Build.VERSION_CODES.O)
    private void initNotificationChannels() {
        NotificationChannel publicChannel = new NotificationChannel(
                Constants.NOTIFICATION_CHANNEL_PUBLIC,
                Constants.NOTIFICATION_CHANNEL_PUBLIC,
                NotificationManager.IMPORTANCE_DEFAULT);
        publicChannel.setDescription(Constants.NOTIFICATION_CHANNEL_PUBLIC);

        NotificationChannel topicChannel = new NotificationChannel(
                Constants.NOTIFICATION_CHANNEL_TOPIC,
                Constants.NOTIFICATION_CHANNEL_TOPIC,
                NotificationManager.IMPORTANCE_DEFAULT);
        topicChannel.setDescription(Constants.NOTIFICATION_CHANNEL_TOPIC);

        NotificationChannel privateChannel = new NotificationChannel(
                Constants.NOTIFICATION_CHANNEL_PRIVATE,
                Constants.NOTIFICATION_CHANNEL_PRIVATE,
                NotificationManager.IMPORTANCE_HIGH);
        privateChannel.setDescription(Constants.NOTIFICATION_CHANNEL_PRIVATE);
        privateChannel.canShowBadge();

        List<NotificationChannel> notificationChannels = new ArrayList<>();
        notificationChannels.add(publicChannel);
        notificationChannels.add(topicChannel);
        notificationChannels.add(privateChannel);

        NotificationManager mNotificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        if (mNotificationManager != null) {
            mNotificationManager.createNotificationChannels(notificationChannels);
        }
    }

然后在我的FirebaseMessagingService，我做了一个函数来获取channelId构建通知时：

    private String getChannelId(String source) {
        if (!TextUtils.isEmpty(source)) {
            if (source.contains(Constants.TOPIC_PREFIX)) {
                return (TextUtils.equals((TOPIC_PREFIX + Constants.NOTIFICATION_CHANNEL_PUBLIC), source)) ?
                        Constants.NOTIFICATION_CHANNEL_PUBLIC : Constants.NOTIFICATION_CHANNEL_TOPIC;
            } else {
                return Constants.NOTIFICATION_CHANNEL_PRIVATE;
            }
        } else {
            return Constants.NOTIFICATION_CHANNEL_PUBLIC;
        }
    }

这满足了我们的应用程序需要的三种类型的通知——公共、主题和私人。您可以自行指定您需要的频道。