Android (闹钟和通知栏的设置)

在界面上得有三个按钮，一个为 设置闹钟的开始时间 setAlarmWeek，一个为取消闹钟的按钮 cancelAlarmWeek， 一个发送通知的按钮 sendNotification。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 

xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" 

android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="设置闹钟(一次)"
        android:onClick="setAlarmOne"
        />
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="设置闹钟(周期)"
        android:onClick="setAlarmWeek"
        />
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="取消闹钟(周期)"
        android:onClick="cancelAlarmWeek"
        />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="发送通知"
        android:onClick="sendNotification"
        />

</LinearLayout>

设置闹钟的方法中
先获得当前的系统时间  小时和分钟

Calendar calendar=Calendar.getInstance();
        int hour=calendar.get(Calendar.HOUR_OF_DAY);
        int minute=calendar.get(Calendar.MINUTE);

再设置时间弹框

 //弹出时间对话框（选择几点几分）
        TimePickerDialog timePickerDialog=new 

TimePickerDialog(this, new 

TimePickerDialog.OnTimeSetListener() {

            @Override
            public void onTimeSet(TimePicker view, int i, 

int i1) {
                Calendar c=Calendar.getInstance();
                c.set(Calendar.HOUR_OF_DAY,i);
                c.set(Calendar.MINUTE,i1);

                //PendingIntent  未来的Intent对象
                //时间一到，发送广播（自定义广播）
                //自定义广播接受者，收广播之后，跳转到

Activity
                //在当前的Activity中播放音乐
                Intent intent=new Intent();
                intent.setAction

("com.example.broadcast.RING");
                pendingIntent = PendingIntent.getBroadcast

(MainActivity.this,0x102,intent,0);
                alarmManager.setRepeating

(AlarmManager.RTC_WAKEUP,c.getTimeInMillis

(),5000,pendingIntent);
            }
        },hour,minute,true);
        timePickerDialog.show();


再用一个广播来发送通知
package com.example.broadcast;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

import com.example.myas_029.RingActivity;

/**
 * Created by Administrator on 2017/7/22 0022.
 */

public class RingReceived extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        if("com.example.broadcast.RING".equals

(intent.getAction())){
            Log.i("test","闹钟响了");

            //在广播中 跳转到Activity
            Intent intent1=new Intent(context, 

RingActivity.class);
            //细节：设置一个Flags
            intent1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(intent1);
        }
    }
}

再从这个广播跳转到专门播放音乐的界面

package com.example.myas_029;

import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;

/**
 * Created by Administrator on 2017/7/22 0022.
 */

public class RingActivity extends AppCompatActivity {

    private MediaPlayer mediaPlayer;

    @Override
    protected void onCreate(@Nullable Bundle 

savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_ring);
        mediaPlayer = MediaPlayer.create(this, R.raw.the);
        mediaPlayer.start();
    }

    public void close(View view){
        mediaPlayer.stop();
        finish();
    }
}