学习安卓中遇到的问题记录

1 获取string.xml文件里的值（已解决）

String itemName=(String)MainActivity.this.getResources().getText(R.string.item_name);

如果直接引用R.string.item_name，返回的结果是一个长整数

2 Android8.0及以上 收不到通知Notification(未解决)

下面代码是IntentService类的子类的onHandleIntent方法中实现的

// 自定义通知ID
int NOTIFICATION_ID = 1;
String channelID = "channel_1";
String channelName = "channel_name_1";
String question = "What is the secret of comedy?";
String answer = "Timing!";
NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
                    .setSmallIcon(android.R.drawable.sym_def_app_icon)
                    .setContentTitle(question)
                    .setChannelId(channelID)
                    .setContentText(answer)
                    .setPriority(NotificationCompat.PRIORITY_HIGH)
                    .setVibrate(new long[] {0, 1000})
                    .setAutoCancel(true);

NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
// 此处必须兼容android O设备，否则系统版本在O以上可能不展示通知栏
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
	NotificationChannel channel = new NotificationChannel(channelID, channelName, NotificationManager.IMPORTANCE_HIGH);
    notificationManager.createNotificationChannel(channel);
            }
            notificationManager.notify(NOTIFICATION_ID, builder.build());

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
这个判断的代码实现，并没有起到实际效果，真机调试的时候仍然显示不出通知栏