上周的随机日期和时间C#

Question

我正在尝试生成上周的开始和结束日期时间。

所以如果今天是2022年2月4日，那么我需要一个上周的随机日期和时间，这样它就可以是

2022年2月2日10:00开始

结束02/02/2022 10:30

请注意，结束时间总是30分钟。

我可以使用这个让日期部分工作

Random gen = new Random();
var start = DateTime.Now.AddDays(-7);
int range = (DateTime.Today - DateTime.Today.AddDays(-7)).Days;
var result = start.AddDays(gen.Next(range));

Answer 1

这应该有效：

Random gen = new Random();
var start = DateTime.Now.AddDays(-7);
start = start.AddDays(gen.Next(6)); // Add 0-6 days
start = start.AddHours(gen.Next(23)); // Add 0-23 hours
start = start.AddMinutes(gen.Next(1)); //Add 0-1 minutes.
var result = new DateTime(
start.Year,
start.Month,
start.Day,
start.Hour,
start.Minute % 2 == 0 ? 0 : 30, // If even then zero, if odd then 30.
0); // 0 seconds

Answer 2

这是一个有趣的挑战。就我个人而言，我喜欢简单的解决方案：

var halfHoursPrWeek = 7 * 24 * 2;
// Get last full hour; ex: 04.02.2022 15:00:00
var previousHour = DateTime.Today.AddHours(DateTime.Now.Hour);
var randomNrOfHalfHours = (new Random()).Next(halfHoursPrWeek);
// ex: 31.01.2022 20:30:00
var sometimeLastWeek = previousHour.AddMinutes(-randomNrOfHalfHours * 30);

Answer 3

正如我在评论中已经说过的，基于记号生成一个DateTime对象。

//startDate 7 days ago, without time so 00:00:00
var startDate = DateTime.Now.Date.AddDays(-7);
//endDate with the time of 23:59:59
//notice manipulating the time this way could lead to a DateTime in the future, if you don't want that only use `DateTime.Now`
var endDate = DateTime.Now.Date.AddDays(1).AddMilliseconds(-1);
//ticks in range of the dateTimes
var ticks = new Random().NextInt64(startDate.Ticks, endDate.Ticks);
//new DateTime
var newDate = new DateTime(ticks);
Console.WriteLine($"NewDate in the range of {startDate} and {endDate}:");
Console.WriteLine(newDate);

https://dotnetfiddle.net/HcyAUD

Answer 4

请参阅以下内容：

const int MINUTES_PER_WEEK = 7 * 24 * 60;
DateTime date = DateTime.Now;
DateTime SundayMidnight = date.AddDays(-(int)date.DayOfWeek).Date;
DateTime startDate = SundayMidnight.AddDays(-7);
Random rand = new Random();
int randomMinutes = rand.Next(MINUTES_PER_WEEK - 30);
DateTime randomStartDate = startDate.AddMinutes(randomMinutes);
DateTime randomEndDate = startDate.AddMinutes(randomMinutes + 30); 

Answer 5

通过记号进行计算。

// One week interval in ticks.
const long WEEK = 6048000000000; 
// Initial date & time.
DateTime now = DateTime.Now;
// Random decrease interval of 1 week.
Random gen = new Random();
long reduce = Convert.ToInt64(gen.NextDouble() * WEEK); 
TimeSpan span = TimeSpan.FromTicks(reduce);
// Determine a random date at last week.
DateTime lastWeek = now - span;

这种方法是基于预先计算从零到1周的时间间隔，然后从当前日期减去这段时间，而其他一些方法则是先减去一周，然后在一周内添加一个随机值，在我看来这是多余的计算。