android通知栏消息

android 在通知栏弹出消息， 看了很多博客，方到代码里都略有问题，最后只能去官方文档找示例。

官方文档

这个通知栏既可以通过service触发，也可以通过activity触发。

public class Notify {

    private NotificationManager manager;
    private Notification.Builder builder;
    private Context context;
    private Notification notification;
    private String TAG = "notify";

    public Notify(Context context){
        this.context = context;
    }

   @TargetApi(26)
    public void setNotification(String title, String desc){

        manager = (NotificationManager)context.getSystemService(context.NOTIFICATION_SERVICE);

        // set channel  chanenel的创建
        String CHANNEL_ONE_ID = "com.zhangshiling.app";
        String CHANNEL_ONE_NAME = "Channel One";
        NotificationChannel notificationChannel;
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            notificationChannel = new NotificationChannel(CHANNEL_ONE_ID,
                    CHANNEL_ONE_NAME, NotificationManager.IMPORTANCE_HIGH);
            /*notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.RED);
            notificationChannel.setShowBadge(true);
            notificationChannel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);*/
            NotificationManager nm = context.getSystemService(NotificationManager.class);
            nm.createNotificationChannel(notificationChannel);
        }

        Intent intent = new Intent(context, message_list.class);
       intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intent, 0);

        builder = new Notification.Builder(context).setContentTitle(title)
                .setChannelId(CHANNEL_ONE_ID)
                .setContentText(desc)
                .setContentIntent(pendingIntent)
                .setWhen(System.currentTimeMillis())
                .setAutoCancel(true)
                .setPriority(NotificationCompat.PRIORITY_DEFAULT)
                .setVibrate(new long[]{0, 1000, 1000, 1000}) //通知栏消息震动
                .setLights(Color.GREEN, 1000, 2000) //通知栏消息闪灯(亮一秒间隔两秒再亮)
                .setDefaults(NotificationCompat.DEFAULT_ALL)
                .setSmallIcon(R.drawable.small_icon);
        Log.i(TAG,"after build a builder");
        //manager.notify(1, builder.getNotification());
        NotificationManagerCompat new_nm = NotificationManagerCompat.from(context);
        new_nm.notify(1, builder.build());  // 第一个参数1具体实现时 需要修改 用于显示不同消息。
        //return builder.getNotification();
    }
  }

在service中

 Notify nm = new Notify(this);
 nm.setNotification(rsp.title, rsp.content);