DateTime.AddSeconds(Double) 方法
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
回傳 DateTime 一個新值,將指定秒數加到該實例值上。
public:
DateTime AddSeconds(double value);
public DateTime AddSeconds(double value);
member this.AddSeconds : double -> DateTime
Public Function AddSeconds (value As Double) As DateTime
參數
- value
- Double
整秒和分秒數。
value參數可以是負也可以是正。
傳回
一個物件,其值為該實例所代表的日期與時間與所代表 value的秒數之和。
例外狀況
範例
以下範例使用 AddSeconds 將 30 秒與一天內的秒數相加於 DateTime 一個數值的方法。 接著它會顯示每個新值,並顯示與原值之間的差異。 差異以時間跨度和刻數顯示。
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)
備註
此方法不會改變此 DateTime值。 取而代之的是,它回傳一個新值 DateTime ,其值即為該操作的結果。
的 value 分數部分是秒的分數部分。 例如,4.5 相當於 4 秒、500 毫秒和 0 tick。
在 .NET Framework 中,參數 value 會四捨五入到最接近的毫秒。 在 .NET 7 及之後版本中,參數的精確度會被使用。Doublevalue 然而,由於浮點數學本身的不精確性,所得精度會有所不同。