Android 使用AlarmManager和NotificationManager来实现闹钟和通知栏

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main"
  android:layout_width="match_parent" android:layout_height="match_parent"
  android:paddingbottom="@dimen/activity_vertical_margin"
  android:paddingleft="@dimen/activity_horizontal_margin"
  android:paddingright="@dimen/activity_horizontal_margin"
  android:paddingtop="@dimen/activity_vertical_margin"
  android:orientation="vertical"
  tools:context="com.example.g150825_android28.mainactivity">
  <button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="设置闹钟（一次）"
    android:onclick="setalarmone"
    />
  <button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="设置闹钟（周期）"
    android:onclick="setalarm"
    />
  <button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="取消周期闹钟"
    android:onclick="cancelalarm"
    />
  <button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="发送通知"
    android:onclick="send"
    />
</linearlayout>

<?xml version="1.0" encoding="utf-8"?>
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:id="@+id/activity_ring"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:paddingbottom="@dimen/activity_vertical_margin"
  android:paddingleft="@dimen/activity_horizontal_margin"
  android:paddingright="@dimen/activity_horizontal_margin"
  android:paddingtop="@dimen/activity_vertical_margin"
  tools:context="com.example.g150825_android28.ringactivity">
  <button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="停止"
    android:onclick="stop"
    android:id="@+id/button"
    android:layout_alignparenttop="true"
    android:layout_alignparentleft="true"
    android:layout_alignparentstart="true" />
  <textview
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="慈禧太后青霜来了，赶紧起床！"
    android:id="@+id/textview"
    android:textsize="30sp"
    android:layout_below="@+id/button"
    android:layout_centerhorizontal="true"
    android:layout_margintop="36dp" />
</relativelayout>

package com.example.g150825_android28;
import android.media.mediaplayer;
import android.support.v7.app.appcompatactivity;
import android.os.bundle;
import android.view.view;
public class ringactivity extends appcompatactivity {
  private mediaplayer mediaplayer;
  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_ring);
    mediaplayer = mediaplayer.create(this, r.raw.sqbm);
    mediaplayer.start();
  }
  public void stop(view view){
    mediaplayer.stop();
    finish();
  }
}

package com.example.g150825_android28;
import android.content.broadcastreceiver;
import android.content.context;
import android.content.intent;
import android.widget.toast;
public class myreceiver extends broadcastreceiver {
  public myreceiver() {
  }
  @override
  public void onreceive(context context, intent intent) {
    if("com.example.g150825_android28.ring".equals(intent.getaction())){
      toast.maketext(context, "闹钟响了", toast.length_short).show();
      //跳转到activity
      intent intent1=new intent(context,ringactivity.class);
      //设置标志位(flag)
      intent1.setflags(intent.flag_activity_new_task);
      context.startactivity(intent1);
    }
  }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.example.g150825_android28">
  <application
    android:allowbackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsrtl="true"
    android:theme="@style/apptheme">
    <activity android:name=".mainactivity">
      <intent-filter>
        <action android:name="android.intent.action.main" />
        <category android:name="android.intent.category.launcher" />
      </intent-filter>
    </activity>
    <receiver
      android:name=".myreceiver"
      android:enabled="true"
      android:exported="true">
      <intent-filter>
        <action android:name="com.example.g150825_android28.ring" />
      </intent-filter>
    </receiver>
    <activity android:name=".ringactivity"
      android:theme="@style/theme.appcompat.dialog"
      ></activity>
  </application>
</manifest>