在app未开启时，实现对用户进行通知提醒功能总结（添加事件到手机系统日历并设置闹钟提醒）

最近在做项目遇到一个需求，在app未开启时，能够对用户进行通知提醒明天有培训课需要参加。最开始想到可以用第三方实现推送，如极光推送、融云推送等，但是这些推送的原理都是采用的长连接，仅仅当你的app在开启状态并且没有被结束进程时才能接收到推送通知，所以并不能实现想要的效果。偶然在玩蘑菇街app的时候发现了它里面有一个抢购提醒功能，原理就是把抢购事件添加到手机系统日历事件中并设置闹钟提醒，这样就保证在你的app被后台杀死后也能在指定的时间做到提醒功能。受到这个的启示，就把想要进行通知的事件添加到手机系统日历中。下面是部分代码。

private static String CALANDER_URL = "content://com.android.calendar/calendars";
private static String CALANDER_EVENT_URL = "content://com.android.calendar/events";
private static String CALANDER_REMIDER_URL = "content://com.android.calendar/reminders";

private static String CALENDARS_NAME = "Mytest";
private static String CALENDARS_ACCOUNT_NAME = "mytest";
private static String CALENDARS_ACCOUNT_TYPE = "calender.test";
private static String CALENDARS_DISPLAY_NAME = "Mytest";

//检查是否有现在存在的账户。存在则返回账户id，否则返回-1
private static int checkCalendarAccount(Context context) {
Cursor userCursor = context.getContentResolver().query(Uri.parse(CALANDER_URL), null, null, null, null);
try {
if (userCursor == null) {
return -1;
} else {
int count = userCursor.getCount();
if (count > 0) {  //存在现有账户，取第一个账户的id返回
userCursor.moveToFirst();
return userCursor.getInt(userCursor.getColumnIndex(CalendarContract.Calendars._ID));
} else {
return -1;
}
}
} finally {
if (userCursor != null) {
userCursor.close();
}
}
}

//添加日历账户
private static long addCalendarAccount(Context context) {
TimeZone timeZone = TimeZone.getDefault();
ContentValues values = new ContentValues();
values.put(CalendarContract.Calendars.NAME, CALENDARS_NAME);
values.put(CalendarContract.Calendars.ACCOUNT_NAME, CALENDARS_DISPLAY_NAME);
values.put(CalendarContract.Calendars.VISIBLE, 1);
values.put(CalendarContract.Calendars.CALENDAR_COLOR, Color.BLUE);
values.put(CalendarContract.Calendars.SYNC_EVENTS, 1);
values.put(CalendarContract.Calendars.CALENDAR_TIME_ZONE, timeZone.getID());
values.put(CalendarContract.Calendars.OWNER_ACCOUNT, CALENDARS_ACCOUNT_NAME);
values.put(CalendarContract.Calendars.CAN_ORGANIZER_RESPOND, 0);
Uri calendarUri = Uri.parse(CALANDER_URL);
calendarUri = calendarUri.buildUpon().appendQueryParameter(CalendarContract.CALLER_IS_SYNCADAPTER, "true").appendQueryParameter(CalendarContract.Calendars.ACCOUNT_NAME, CALENDARS_ACCOUNT_NAME).appendQueryParameter(CalendarContract.Calendars.ACCOUNT_TYPE, CALENDARS_ACCOUNT_TYPE).build();

Uri result = context.getContentResolver().insert(calendarUri, values);
long id = result == null ? -1 : ContentUris.parseId(result);
return id;
}

//检查是否已经添加了日历账户，如果没有添加先添加一个日历账户再查询
private static int checkAndAddCalendarAccount(Context context) {
int oldId = checkCalendarAccount(context);
if (oldId >= 0) {
return oldId;
} else {
long addId = addCalendarAccount(context);
if (addId >= 0) {
return checkCalendarAccount(context);
} else {
return -1;
}

}
}
//添加日历事件
public static void addCalenderEvent(Context context, String title, String description, long beginTime) {
//获取日历账户的id
int calId = checkAndAddCalendarAccount(context);
if (calId < 0) {
//获取日历账户id失败，直接返回，添加日历事件失败
Log.d("tag","添加失败！");
return;
}
ContentValues values = new ContentValues();
values.put("title", title);
values.put("description", description);
values.put("calendar_id", calId);
Calendar mCalendar = Calendar.getInstance();
mCalendar.setTimeInMillis(beginTime);  //设置开始时间
long start = mCalendar.getTime().getTime();
mCalendar.setTimeInMillis(start + ONE_HOUR);//设置终止时间
long end = mCalendar.getTime().getTime();
values.put(CalendarContract.Events.DTSTART, start);
values.put(CalendarContract.Events.DTEND, end);
values.put(CalendarContract.Events.HAS_ALARM, true);//设置有闹钟提醒
values.put(CalendarContract.Events.EVENT_TIMEZONE, "Asia/Shanghai"); //这个是时区，必须有
values.put(CalendarContract.Events.STATUS,1);
Uri newEvent = context.getContentResolver().insert(Uri.parse(CALANDER_EVENT_URL), values);

if (newEvent == null) {
//添加日历事件失败直接返回
Log.d("tag","添加失败！");
return;
}

ContentValues values1new = new ContentValues();
values1new.put(CalendarContract.Reminders.EVENT_ID, ContentUris.parseId(newEvent));
values1new.put(CalendarContract.Reminders.MINUTES, 1440);  //提前一天有提醒  1440
values1new .put(CalendarContract.Reminders.METHOD,1);

Uri uri = context.getContentResolver().insert(Uri.parse(CALANDER_REMIDER_URL), values1new);
if (uri == null) {
//添加闹钟提醒失败直接返回
Log.d("tag","添加失败！");
return;
}else {
Log.d("tag","添加成功！"+uri);
}
}

//Button按钮点击事件
public void ClickThred(View view) {

long timeMillis = System.currentTimeMillis();
addCalenderEvent(getApplicationContext(),"课程提醒:您明天有课程要参加，请不要忘记呦","有课程即将开始，请及时查看",timeMillis);

}