DateTime.AddSeconds(Double) 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
返回一个新的 DateTime,它将指定的秒数加到此实例的值上。
public:
DateTime AddSeconds(double value);
public DateTime AddSeconds (double value);
member this.AddSeconds : double -> DateTime
Public Function AddSeconds (value As Double) As DateTime
参数
- value
- Double
由整数和小数部分组成的秒数。
value
参数可以是负数也可以是正数。
返回
一个对象,其值是此实例所表示的日期和时间与 value
所表示的秒数之和。
例外
示例
以下示例使用 AddSeconds 方法将 30 秒和一天中的秒数添加到值 DateTime 。 然后,它显示每个新值,并显示它与原始值之间的差异。 差异同时显示为时间跨度和时钟周期数。
using System;
public class Example
{
public static void Main()
{
string dateFormat = "MM/dd/yyyy hh:mm:ss";
DateTime date1 = new DateTime(2014, 9, 8, 16, 0, 0);
Console.WriteLine("Original date: {0} ({1:N0} ticks)\n",
date1.ToString(dateFormat), date1.Ticks);
DateTime date2 = date1.AddSeconds(30);
Console.WriteLine("Second date: {0} ({1:N0} ticks)",
date2.ToString(dateFormat), date2.Ticks);
Console.WriteLine("Difference between dates: {0} ({1:N0} ticks)\n",
date2 - date1, date2.Ticks - date1.Ticks);
// Add 1 day's worth of seconds (60 secs. * 60 mins * 24 hrs.
DateTime date3 = date1.AddSeconds(60 * 60 * 24);
Console.WriteLine("Third date: {0} ({1:N0} ticks)",
date3.ToString(dateFormat), date3.Ticks);
Console.WriteLine("Difference between dates: {0} ({1:N0} ticks)",
date3 - date1, date3.Ticks - date1.Ticks);
}
}
// The example displays the following output:
// Original date: 09/08/2014 04:00:00 (635,457,888,000,000,000 ticks)
//
// Second date: 09/08/2014 04:00:30 (635,457,888,300,000,000 ticks)
// Difference between dates: 00:00:30 (300,000,000 ticks)
//
// Third date: 09/09/2014 04:00:00 (635,458,752,000,000,000 ticks)
// Difference between dates: 1.00:00:00 (864,000,000,000 ticks)
open System
let dateFormat = "MM/dd/yyyy hh:mm:ss"
let date1 = DateTime(2014, 9, 8, 16, 0, 0)
printfn $"Original date: {date1.ToString dateFormat} ({date1.Ticks:N0} ticks)\n"
let date2 = date1.AddSeconds 30
printfn $"Second date: {date2.ToString dateFormat} ({date2.Ticks:N0} ticks)"
printfn $"Difference between dates: {date2 - date1} ({date2.Ticks - date1.Ticks:N0} ticks)\n"
// Add 1 day's worth of seconds (60 secs. * 60 mins * 24 hrs.
let date3 = date1.AddSeconds(60. * 60. * 24.)
printfn $"Third date: {date3.ToString dateFormat} ({date3.Ticks:N0} ticks)"
printfn $"Difference between dates: {date3 - date1} ({date3.Ticks - date1.Ticks:N0} ticks)"
// The example displays the following output:
// Original date: 09/08/2014 04:00:00 (635,457,888,000,000,000 ticks)
//
// Second date: 09/08/2014 04:00:30 (635,457,888,300,000,000 ticks)
// Difference between dates: 00:00:30 (300,000,000 ticks)
//
// Third date: 09/09/2014 04:00:00 (635,458,752,000,000,000 ticks)
// Difference between dates: 1.00:00:00 (864,000,000,000 ticks)
Module Example
Public Sub Main()
Dim dateFormat As String = "MM/dd/yyyy hh:mm:ss"
Dim date1 As Date = #09/08/2014 16:00#
Console.WriteLine("Original date: {0} ({1:N0} ticks)", _
date1.ToString(dateFormat), date1.Ticks)
Console.WriteLine()
Dim date2 As Date = date1.AddSeconds(30)
Console.WriteLine("Second date: {0} ({1:N0} ticks)", _
date2.ToString(dateFormat), date2.Ticks)
Console.WriteLine("Difference between dates: {0} ({1:N0} ticks)", _
date2 - date1, date2.Ticks - date1.Ticks)
Console.WriteLine()
' Add 1 day's worth of seconds (60 secs. * 60 mins * 24 hrs.
Dim date3 As Date = date1.AddSeconds(60 * 60 * 24)
Console.WriteLine("Third date: {0} ({1:N0} ticks)", _
date3.ToString(dateFormat), date3.Ticks)
Console.WriteLine("Difference between dates: {0} ({1:N0} ticks)", _
date3 - date1, date3.Ticks - date1.Ticks)
End Sub
End Module
' The example displays the following output:
' Original date: 09/08/2014 04:00:00 (635,457,888,000,000,000 ticks)
'
' Second date: 09/08/2014 04:00:30 (635,457,888,300,000,000 ticks)
' Difference between dates: 00:00:30 (300,000,000 ticks)
'
' Third date: 09/09/2014 04:00:00 (635,458,752,000,000,000 ticks)
' Difference between dates: 1.00:00:00 (864,000,000,000 ticks)
注解
此方法不会更改此 DateTime的值。 相反,它返回一个新的 DateTime ,其值是此操作的结果。
的小数部分 value
是秒的小数部分。 例如,4.5 相当于 4 秒、500 毫秒和 0 个时钟周期。
在 .NET 6 及更早版本中, value
参数四舍五入为最接近的毫秒。 在 .NET 7 及更高版本中,将使用 参数的完整Doublevalue
精度。 但是,由于浮点数学固有的不精确性,生成的精度将有所不同。