java/ui/AlarmInitReceiver.java

/*
 * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// 定义一个广播接收器，用于初始化闹钟
public class AlarmInitReceiver extends BroadcastReceiver {

    // 静态字段，定义投影的列
    private static final String [] PROJECTION = new String [] {
        NoteColumns.ID,
        NoteColumns.ALERTED_DATE
    };

    // 定义投影列的索引
    private static final int COLUMN_ID                = 0;
    private static final int COLUMN_ALERTED_DATE      = 1;

    @Override
    public void onReceive(Context context, Intent intent) {
        // 获取当前时间的时间戳
        long currentDate = System.currentTimeMillis();
        // 获取内容解析器的实例
        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()) {
                // 如果查询结果有数据，循环处理
                do {
                    // 获取闹钟提醒的时间戳
                    long alertDate = c.getLong(COLUMN_ALERTED_DATE);
                    // 创建一个意图，指向AlarmReceiver类
                    Intent sender = new Intent(context, AlarmReceiver.class);
                    // 设置意图的数据为笔记的Uri，并通过ID来唯一标识
                    sender.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, c.getLong(COLUMN_ID)));
                    // 创建一个挂起意图，用于在指定时间发送广播
                    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, sender, 0);
                    // 获取AlarmManager的实例
                    AlarmManager alermManager = (AlarmManager) context
                            .getSystemService(Context.ALARM_SERVICE);
                    // 设置闹钟，在指定的时间戳前触发，并使用挂起意图发送广播
                    alermManager.set(AlarmManager.RTC_WAKEUP, alertDate, pendingIntent);
                } while (c.moveToNext());
            }
            // 关闭游标
            c.close();
        }
    }
}