给定特定的DateTime值,如何显示相对时间,例如:
2小时前3天前一个月前
给定特定的DateTime值,如何显示相对时间,例如:
2小时前3天前一个月前
当前回答
我将为此提供一些方便的扩展方法,并使代码更可读。首先,Int32的两个扩展方法。
public static class TimeSpanExtensions {
public static TimeSpan Days(this int value) {
return new TimeSpan(value, 0, 0, 0);
}
public static TimeSpan Hours(this int value) {
return new TimeSpan(0, value, 0, 0);
}
public static TimeSpan Minutes(this int value) {
return new TimeSpan(0, 0, value, 0);
}
public static TimeSpan Seconds(this int value) {
return new TimeSpan(0, 0, 0, value);
}
public static TimeSpan Milliseconds(this int value) {
return new TimeSpan(0, 0, 0, 0, value);
}
public static DateTime Ago(this TimeSpan value) {
return DateTime.Now - value;
}
}
然后,为DateTime设置一个。
public static class DateTimeExtensions {
public static DateTime Ago(this DateTime dateTime, TimeSpan delta) {
return dateTime - delta;
}
}
现在,您可以执行以下操作:
var date = DateTime.Now;
date.Ago(2.Days()); // 2 days ago
date.Ago(7.Hours()); // 7 hours ago
date.Ago(567.Milliseconds()); // 567 milliseconds ago
其他回答
鉴于全世界和她的丈夫似乎都在发布代码样本,这是我不久前根据这些答案写的。
我特别需要这个代码可以本地化。所以我有两个类——Grammar,它指定了可本地化的术语,FuzzyDateExtensions,它包含一系列扩展方法。我不需要处理未来的日期时间,因此不尝试使用此代码处理它们。
为了简洁起见,我在源代码中保留了一些XMLdoc,但删除了大部分(显而易见的地方)。我也没有把每个班级成员都包括在这里:
public class Grammar
{
/// <summary> Gets or sets the term for "just now". </summary>
public string JustNow { get; set; }
/// <summary> Gets or sets the term for "X minutes ago". </summary>
/// <remarks>
/// This is a <see cref="String.Format"/> pattern, where <c>{0}</c>
/// is the number of minutes.
/// </remarks>
public string MinutesAgo { get; set; }
public string OneHourAgo { get; set; }
public string HoursAgo { get; set; }
public string Yesterday { get; set; }
public string DaysAgo { get; set; }
public string LastMonth { get; set; }
public string MonthsAgo { get; set; }
public string LastYear { get; set; }
public string YearsAgo { get; set; }
/// <summary> Gets or sets the term for "ages ago". </summary>
public string AgesAgo { get; set; }
/// <summary>
/// Gets or sets the threshold beyond which the fuzzy date should be
/// considered "ages ago".
/// </summary>
public TimeSpan AgesAgoThreshold { get; set; }
/// <summary>
/// Initialises a new <see cref="Grammar"/> instance with the
/// specified properties.
/// </summary>
private void Initialise(string justNow, string minutesAgo,
string oneHourAgo, string hoursAgo, string yesterday, string daysAgo,
string lastMonth, string monthsAgo, string lastYear, string yearsAgo,
string agesAgo, TimeSpan agesAgoThreshold)
{ ... }
}
FuzzyDateString类包含:
public static class FuzzyDateExtensions
{
public static string ToFuzzyDateString(this TimeSpan timespan)
{
return timespan.ToFuzzyDateString(new Grammar());
}
public static string ToFuzzyDateString(this TimeSpan timespan,
Grammar grammar)
{
return GetFuzzyDateString(timespan, grammar);
}
public static string ToFuzzyDateString(this DateTime datetime)
{
return (DateTime.Now - datetime).ToFuzzyDateString();
}
public static string ToFuzzyDateString(this DateTime datetime,
Grammar grammar)
{
return (DateTime.Now - datetime).ToFuzzyDateString(grammar);
}
private static string GetFuzzyDateString(TimeSpan timespan,
Grammar grammar)
{
timespan = timespan.Duration();
if (timespan >= grammar.AgesAgoThreshold)
{
return grammar.AgesAgo;
}
if (timespan < new TimeSpan(0, 2, 0)) // 2 minutes
{
return grammar.JustNow;
}
if (timespan < new TimeSpan(1, 0, 0)) // 1 hour
{
return String.Format(grammar.MinutesAgo, timespan.Minutes);
}
if (timespan < new TimeSpan(1, 55, 0)) // 1 hour 55 minutes
{
return grammar.OneHourAgo;
}
if (timespan < new TimeSpan(12, 0, 0) // 12 hours
&& (DateTime.Now - timespan).IsToday())
{
return String.Format(grammar.HoursAgo, timespan.RoundedHours());
}
if ((DateTime.Now.AddDays(1) - timespan).IsToday())
{
return grammar.Yesterday;
}
if (timespan < new TimeSpan(32, 0, 0, 0) // 32 days
&& (DateTime.Now - timespan).IsThisMonth())
{
return String.Format(grammar.DaysAgo, timespan.RoundedDays());
}
if ((DateTime.Now.AddMonths(1) - timespan).IsThisMonth())
{
return grammar.LastMonth;
}
if (timespan < new TimeSpan(365, 0, 0, 0, 0) // 365 days
&& (DateTime.Now - timespan).IsThisYear())
{
return String.Format(grammar.MonthsAgo, timespan.RoundedMonths());
}
if ((DateTime.Now - timespan).AddYears(1).IsThisYear())
{
return grammar.LastYear;
}
return String.Format(grammar.YearsAgo, timespan.RoundedYears());
}
}
我想实现的一件关键事情,以及本地化,就是“今天”只意味着“这个日历日”,所以IsToday、IsThisMonth和IsThisYear方法如下:
public static bool IsToday(this DateTime date)
{
return date.DayOfYear == DateTime.Now.DayOfYear && date.IsThisYear();
}
舍入方法如下(我已包括RoundedMonths,因为这有点不同):
public static int RoundedDays(this TimeSpan timespan)
{
return (timespan.Hours > 12) ? timespan.Days + 1 : timespan.Days;
}
public static int RoundedMonths(this TimeSpan timespan)
{
DateTime then = DateTime.Now - timespan;
// Number of partial months elapsed since 1 Jan, AD 1 (DateTime.MinValue)
int nowMonthYears = DateTime.Now.Year * 12 + DateTime.Now.Month;
int thenMonthYears = then.Year * 12 + then.Month;
return nowMonthYears - thenMonthYears;
}
我希望人们觉得这很有用和/或有趣:o)
public static string RelativeDate(DateTime theDate)
{
Dictionary<long, string> thresholds = new Dictionary<long, string>();
int minute = 60;
int hour = 60 * minute;
int day = 24 * hour;
thresholds.Add(60, "{0} seconds ago");
thresholds.Add(minute * 2, "a minute ago");
thresholds.Add(45 * minute, "{0} minutes ago");
thresholds.Add(120 * minute, "an hour ago");
thresholds.Add(day, "{0} hours ago");
thresholds.Add(day * 2, "yesterday");
thresholds.Add(day * 30, "{0} days ago");
thresholds.Add(day * 365, "{0} months ago");
thresholds.Add(long.MaxValue, "{0} years ago");
long since = (DateTime.Now.Ticks - theDate.Ticks) / 10000000;
foreach (long threshold in thresholds.Keys)
{
if (since < threshold)
{
TimeSpan t = new TimeSpan((DateTime.Now.Ticks - theDate.Ticks));
return string.Format(thresholds[threshold], (t.Days > 365 ? t.Days / 365 : (t.Days > 0 ? t.Days : (t.Hours > 0 ? t.Hours : (t.Minutes > 0 ? t.Minutes : (t.Seconds > 0 ? t.Seconds : 0))))).ToString());
}
}
return "";
}
我更喜欢这个版本,因为它简洁,并且能够添加新的刻度点。这可以用Timespan的Latest()扩展来封装,而不是长的1行,但为了发布的简洁,这可以。这修复了一小时前、一小时前的问题,提供了一个小时直到两小时过去
var ts = new TimeSpan(DateTime.Now.Ticks - dt.Ticks);
// Calculate total days in current year
int daysInYear;
for (var i = 1; i <= 12; i++)
daysInYear += DateTime.DaysInMonth(DateTime.Now.Year, i);
// Past date
DateTime dateToCompare = DateTime.Now.Subtract(TimeSpan.FromMinutes(582));
// Calculate difference between current date and past date
double diff = (DateTime.Now - dateToCompare).TotalMilliseconds;
TimeSpan ts = TimeSpan.FromMilliseconds(diff);
var years = ts.TotalDays / daysInYear; // Years
var months = ts.TotalDays / (daysInYear / (double)12); // Months
var weeks = ts.TotalDays / 7; // Weeks
var days = ts.TotalDays; // Days
var hours = ts.TotalHours; // Hours
var minutes = ts.TotalMinutes; // Minutes
var seconds = ts.TotalSeconds; // Seconds
if (years >= 1)
Console.WriteLine(Math.Round(years, 0) + " year(s) ago");
else if (months >= 1)
Console.WriteLine(Math.Round(months, 0) + " month(s) ago");
else if (weeks >= 1)
Console.WriteLine(Math.Round(weeks, 0) + " week(s) ago");
else if (days >= 1)
Console.WriteLine(Math.Round(days, 0) + " days(s) ago");
else if (hours >= 1)
Console.WriteLine(Math.Round(hours, 0) + " hour(s) ago");
else if (minutes >= 1)
Console.WriteLine(Math.Round(minutes, 0) + " minute(s) ago");
else if (seconds >= 1)
Console.WriteLine(Math.Round(seconds, 0) + " second(s) ago");
Console.ReadLine();
Nuget上还有一个名为Humanizr的软件包,它实际上运行得很好,并且在.NET Foundation中。
DateTime.UtcNow.AddHours(-30).Humanize() => "yesterday"
DateTime.UtcNow.AddHours(-2).Humanize() => "2 hours ago"
DateTime.UtcNow.AddHours(30).Humanize() => "tomorrow"
DateTime.UtcNow.AddHours(2).Humanize() => "2 hours from now"
TimeSpan.FromMilliseconds(1299630020).Humanize() => "2 weeks"
TimeSpan.FromMilliseconds(1299630020).Humanize(3) => "2 weeks, 1 day, 1 hour"
Scott Hanselman在他的博客上写了一篇文章