Android的短信的时间的显示做的很精细,首先保存在短信数据库mmssms.db中的短信时间都是Long型的数字,查询动作结束,取到这个值之后,会做转换,具体转换的动作在MessageUtils.java的formatTimeStampString函数中完成;
时间转换:
public static String formatTimeStampString(Context context, long when) {
return formatTimeStampString(context, when, false);
}
formatTimeStampString
public static String formatTimeStampString(Context context, long when, boolean fullFormat) {
Time then = new Time();
then.set(when);
Time now = new Time();
now.setToNow();
// Basic settings for formatDateTime() we want for all cases.
int format_flags = DateUtils.FORMAT_NO_NOON_MIDNIGHT |
DateUtils.FORMAT_ABBREV_ALL |
DateUtils.FORMAT_CAP_AMPM;
// If the message is from a different year, show the date and year.
if (then.year != now.year) {
format_flags |= DateUtils.FORMAT_SHOW_YEAR | DateUtils.FORMAT_SHOW_DATE;
} else if (then.yearDay != now.yearDay) {
// If it is from a different day than today, show only the date.
format_flags |= DateUtils.FORMAT_SHOW_DATE;
} else {
// Otherwise, if the message is from today, show the time.
format_flags |= DateUtils.FORMAT_SHOW_TIME;
}
// If the caller has asked for full details, make sure to show the date
// and time no matter what we've determined above (but still make showing
// the year only happen if it is a different year from today).
if (fullFormat) {
format_flags |= (DateUtils.FORMAT_SHOW_DATE | DateUtils.FORMAT_SHOW_TIME);
}
return DateUtils.formatDateTime(context, when, format_flags);
}
从第二个具体实现的函数可以看出来,Android是根据当前的时间为比较的依据来决定显示的时间格式:
如果当前的短信时间中年份跟手机当前的年份不一致,则显示年月日,不显示具体的几点几分,如:2010-6-30; 如果短信的时间跟手机当前时间在同一年,但不是同一天,则只显示月日,如:6月29日; 如果是当天的短信,则会计算是上午还是下午的短信,同时显示几点几分记录的该短信,如:下午 12:55;综合考虑下来,这样的显示设计还是很合理的…