diff --git a/AlarmInitReceiver.java b/AlarmInitReceiver.java new file mode 100644 index 0000000..c1e7d08 --- /dev/null +++ b/AlarmInitReceiver.java @@ -0,0 +1,75 @@ +/* + * 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. + */ + +package net.micode.notes.ui; // 指定该类所在的包路径 + +import android.app.AlarmManager; // 引入AlarmManager类,用于设置闹钟 +import android.app.PendingIntent; // 引入PendingIntent类,表示延迟的Intent +import android.content.BroadcastReceiver; // 引入BroadcastReceiver类,用于接收广播 +import android.content.ContentUris; // 引入ContentUris类,用于生成URI +import android.content.Context; // 引入Context类,用于访问系统资源 +import android.content.Intent; // 引入Intent类,用于启动组件 +import android.database.Cursor; // 引入Cursor类,用于数据库查询 + +import net.micode.notes.data.Notes; // 引入Notes类,处理笔记数据 +import net.micode.notes.data.Notes.NoteColumns; // 引入NoteColumns类,表示Notes表的列 + +public class AlarmInitReceiver extends BroadcastReceiver { // 定义一个继承自BroadcastReceiver的类 + + // 定义查询需要的列 + private static final String [] PROJECTION = new String [] { + NoteColumns.ID, // 获取笔记的ID列 + NoteColumns.ALERTED_DATE // 获取提醒时间列 + }; + + // 列索引常量 + private static final int COLUMN_ID = 0; // 第0列是ID列 + private static final int COLUMN_ALERTED_DATE = 1; // 第1列是提醒时间列 + + @Override + public void onReceive(Context context, Intent intent) { // 重写onReceive方法,接收广播 + long currentDate = System.currentTimeMillis(); // 获取当前的系统时间(以毫秒为单位) + + // 查询数据库,获取需要提醒的笔记,且提醒时间大于当前时间 + Cursor c = context.getContentResolver().query(Notes.CONTENT_NOTE_URI, // 查询URI为Notes.CONTENT_NOTE_URI的内容提供者 + PROJECTION, // 需要查询的列 + NoteColumns.ALERTED_DATE + ">? AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE, // 查询条件:提醒时间大于当前时间,且类型为笔记 + new String[] { String.valueOf(currentDate) }, // 查询条件中的当前时间 + null); // 不需要排序 + + // 如果查询结果不为空 + if (c != null) { + // 如果查询到至少一条记录 + if (c.moveToFirst()) { + do { + long alertDate = c.getLong(COLUMN_ALERTED_DATE); // 获取提醒时间 + Intent sender = new Intent(context, AlarmReceiver.class); // 创建一个新的Intent,用于发送广播 + sender.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, c.getLong(COLUMN_ID))); // 设置Intent的数据(笔记的ID) + + // 创建PendingIntent,表示在指定时间执行AlarmReceiver广播 + PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, sender, 0); + + // 获取系统的AlarmManager服务 + AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); + + // 设置闹钟,使用RTC_WAKEUP模式,当到达指定的提醒时间时唤醒设备并触发PendingIntent + alarmManager.set(AlarmManager.RTC_WAKEUP, alertDate, pendingIntent); + } while (c.moveToNext()); // 如果查询结果中还有下一条记录,则继续处理 + } + c.close(); // 关闭Cursor + } + } +}