test-1/AlarmInitReceiver.java

package net.micode.notes.ui;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.ContentUris;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;

import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.NoteColumns;

// 闹钟初始化接收器类，用于在系统启动或其他合适时机初始化闹钟提醒
public class AlarmInitReceiver extends BroadcastReceiver {

    // 查询笔记ID和提醒日期的投影
    private static final String[] PROJECTION = new String[]{
            NoteColumns.ID,
            NoteColumns.ALERTED_DATE
    };
    // 投影中ID列的索引
    private static final int COLUMN_ID = 0;
    // 投影中提醒日期列的索引
    private static final int COLUMN_ALERTED_DATE = 1;

    // 当接收到广播时调用
    @Override
    public void onReceive(Context context, Intent intent) {
        // 获取当前时间
        long currentDate = System.currentTimeMillis();
        // 查询数据库中提醒日期大于当前时间且类型为笔记的记录
        Cursor c = context.getContentResolver().query(Notes.CONTENT_NOTE_URI,
                PROJECTION,
                NoteColumns.ALERTED_DATE + ">? AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE,
                new String[]{String.valueOf(currentDate)},
                null);
        if (c!= null) {
            if (c.moveToFirst()) {
                do {
                    // 获取提醒日期
                    long alertDate = c.getLong(COLUMN_ALERTED_DATE);
                    // 创建一个意图，用于启动AlarmReceiver
                    Intent sender = new Intent(context, AlarmReceiver.class);
                    // 设置意图的数据为当前笔记的Uri
                    sender.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, c.getLong(COLUMN_ID)));
                    // 创建一个PendingIntent，用于发送广播
                    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, sender, 0);
                    // 获取AlarmManager系统服务
                    AlarmManager alermManager = (AlarmManager) context
                          .getSystemService(Context.ALARM_SERVICE);
                    // 设置闹钟，在提醒日期触发广播
                    alermManager.set(AlarmManager.RTC_WAKEUP, alertDate, pendingIntent);
                } while (c.moveToNext());
            }
            c.close();
        }
    }
}