为什么我的Android studio程序运行不出来

Question

主java：

package com.example.administrator.myapplication932;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.RequiresApi;

public class MainActivity extends Activity {
    final int NOTIFYID=0x123;
    @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final NotificationManager notificationManager=
                (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
        Notification.Builder notification=new Notification.Builder(this);
        notification.setAutoCancel(true);
        notification.setSmallIcon(R.drawable.packet);
        notification.setContentTitle("奖励百万红包！！！");
        notification.setContentText("点击查看详情！");
        notification.setDefaults(Notification.DEFAULT_SOUND|Notification.DEFAULT_VIBRATE);
        notification.setWhen(System.currentTimeMillis());
        Intent intent=new Intent(MainActivity.this, Detail.class);
        PendingIntent pi=PendingIntent.getActivity(MainActivity.this,0,intent,0);
        notification.setContentIntent(pi);
            notificationManager.notify(NOTIFYID,notification.build());
    }
}

主活动：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background"
    tools:context=".MainActivity">


</RelativeLayout>

detial java：

package com.example.administrator.myapplication932;

import android.app.Activity;
import android.os.Bundle;

public class Detail extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_detail);
    }
}

detial活动：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/img"
    tools:context=".Detail">

</RelativeLayout>

没报错

Answer 1

你写的是一个通知吧，通知需要加载在管道上才能使用

如果您以 Android 8.0（API 级别 26）为目标平台，并在未指定通知渠道的情况下发布了一条通知，则该通知不会显示且系统会记录错误

如下面这种：

 private String createNotificationChannel(String channelID, String channelNAME, int level) {
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
            NotificationChannel channel = new NotificationChannel(channelID, channelNAME, level);
            manager.createNotificationChannel(channel);
            return channelID;
        } else {
            return null;
        }
    }

NotificationManager manager= (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
String channel = createNotificationChannel("myChannelID", "myChannel", NotificationManager.IMPORTANCE_HIGH);
Notification notification=new NotificationCompat.Builder(this,channel)
        .setContentTitle("测试通知，这是Title")
        .setContentText("这只一段文本，这是Text")
        .setWhen(System.currentTimeMillis())
        .setSmallIcon(R.mipmap.ic_launcher)
        .setLargeIcon(BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher)).build();
manager.notify(1,notification);