DateTime.Now 屬性

參考

定義

命名空間:: System

組件:: System.Runtime.dll

組件:: netstandard.dll

組件:: mscorlib.dll

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。

取得 DateTime 物件，此物件會設定為這部電腦上目前的日期和時間，以本地時間表示。

public:
 static property DateTime Now { DateTime get(); };

public static DateTime Now { get; }

member this.Now : DateTime

Public Shared ReadOnly Property Now As DateTime

屬性值

DateTime

物件，其值為目前的本地日期和時間。

範例

下列範例會使用 Now 和 UtcNow 屬性，以取得目前的本機日期和時間，以及目前的全球協調 (UTC) 日期和時間。然後，它會使用許多文化特性的格式化慣例來顯示字串，以及它們的 Kind 屬性值。

using namespace System;
using namespace System::Globalization;

void main()
{
   DateTime localDate = DateTime::Now;
   DateTime utcDate = DateTime::UtcNow;
   array<String^>^ cultureNames = { "en-US", "en-GB", "fr-FR",
                                    "de-DE", "ru-RU" } ;

   for each (String^ cultureName in cultureNames) {
      CultureInfo^ culture = gcnew CultureInfo(cultureName);
      Console::WriteLine("{0}:", culture->NativeName);
      Console::WriteLine("   Local date and time: {0}, {1:G}",
                         localDate.ToString(culture), localDate.Kind);
      Console::WriteLine("   UTC date and time: {0}, {1:G}\n",
                         utcDate.ToString(culture), utcDate.Kind);
   }
}
// The example displays the following output:
//       English (United States):
//          Local date and time: 6/19/2015 10:35:50 AM, Local
//          UTC date and time: 6/19/2015 5:35:50 PM, Utc
//
//       English (United Kingdom):
//          Local date and time: 19/06/2015 10:35:50, Local
//          UTC date and time: 19/06/2015 17:35:50, Utc
//
//       français (France):
//          Local date and time: 19/06/2015 10:35:50, Local
//          UTC date and time: 19/06/2015 17:35:50, Utc
//
//       Deutsch (Deutschland):
//          Local date and time: 19.06.2015 10:35:50, Local
//          UTC date and time: 19.06.2015 17:35:50, Utc
//
//       русский (Россия):
//          Local date and time: 19.06.2015 10:35:50, Local
//          UTC date and time: 19.06.2015 17:35:50, Utc

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      DateTime localDate = DateTime.Now;
      DateTime utcDate = DateTime.UtcNow;
      String[] cultureNames = { "en-US", "en-GB", "fr-FR",
                                "de-DE", "ru-RU" } ;

      foreach (var cultureName in cultureNames) {
         var culture = new CultureInfo(cultureName);
         Console.WriteLine("{0}:", culture.NativeName);
         Console.WriteLine("   Local date and time: {0}, {1:G}",
                           localDate.ToString(culture), localDate.Kind);
         Console.WriteLine("   UTC date and time: {0}, {1:G}\n",
                           utcDate.ToString(culture), utcDate.Kind);
      }
   }
}
// The example displays the following output:
//       English (United States):
//          Local date and time: 6/19/2015 10:35:50 AM, Local
//          UTC date and time: 6/19/2015 5:35:50 PM, Utc
//
//       English (United Kingdom):
//          Local date and time: 19/06/2015 10:35:50, Local
//          UTC date and time: 19/06/2015 17:35:50, Utc
//
//       français (France):
//          Local date and time: 19/06/2015 10:35:50, Local
//          UTC date and time: 19/06/2015 17:35:50, Utc
//
//       Deutsch (Deutschland):
//          Local date and time: 19.06.2015 10:35:50, Local
//          UTC date and time: 19.06.2015 17:35:50, Utc
//
//       русский (Россия):
//          Local date and time: 19.06.2015 10:35:50, Local
//          UTC date and time: 19.06.2015 17:35:50, Utc

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim localDate = DateTime.Now
      Dim utcDate = DateTime.UtcNow
      Dim cultureNames() As String = { "en-US", "en-GB", "fr-FR",
                                       "de-DE", "ru-RU" }

      For Each cultureName In cultureNames
         Dim culture As New CultureInfo(cultureName)
         Console.WriteLine("{0}:", culture.NativeName)
         Console.WriteLine("   Local date and time: {0}, {1:G}",
                           localDate.ToString(culture), localDate.Kind)
         Console.WriteLine("   UTC date and time: {0}, {1:G}",
                           utcDate.ToString(culture), utcDate.Kind)
         Console.WriteLine()
      Next
   End Sub
End Module
' The example displays the following output:
'       English (United States):
'          Local date and time: 6/19/2015 10:35:50 AM, Local
'          UTC date and time: 6/19/2015 5:35:50 PM, Utc
'
'       English (United Kingdom):
'          Local date and time: 19/06/2015 10:35:50, Local
'          UTC date and time: 19/06/2015 17:35:50, Utc
'
'       français (France):
'          Local date and time: 19/06/2015 10:35:50, Local
'          UTC date and time: 19/06/2015 17:35:50, Utc
'
'       Deutsch (Deutschland):
'          Local date and time: 19.06.2015 10:35:50, Local
'          UTC date and time: 19.06.2015 17:35:50, Utc
'
'       русский (Россия):
'          Local date and time: 19.06.2015 10:35:50, Local
'          UTC date and time: 19.06.2015 17:35:50, Utc

備註

Now屬性 DateTime 會傳回值，表示本機電腦上目前的日期和時間。請注意，值之間有差異 DateTime ，表示自0001年1月1日午夜起經過的刻度數目，以及該值的字串表示，這會以特定文化特性的格式來表示 DateTime 日期和時間值。如需格式化日期和時間值的詳細資訊，請參閱 ToString 方法。下列範例會顯示多個特定文化特性格式的簡短日期和時間字串。

using namespace System;
using namespace System::Globalization;

void main()
{
   DateTime localDate = DateTime::Now;
   array<String^>^ cultureNames = { "en-US", "en-GB", "fr-FR",
                                    "de-DE", "ru-RU" };

   for each (String^ cultureName in cultureNames) {
      CultureInfo^ culture = gcnew CultureInfo(cultureName);
      Console::WriteLine("{0}: {1}", cultureName,
                         localDate.ToString(culture));
   }
}
// The example displays the following output:
//       en-US: 6/19/2015 10:03:06 AM
//       en-GB: 19/06/2015 10:03:06
//       fr-FR: 19/06/2015 10:03:06
//       de-DE: 19.06.2015 10:03:06
//       ru-RU: 19.06.2015 10:03:06

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      DateTime localDate = DateTime.Now;
      String[] cultureNames = { "en-US", "en-GB", "fr-FR",
                                "de-DE", "ru-RU" };

      foreach (var cultureName in cultureNames) {
         var culture = new CultureInfo(cultureName);
         Console.WriteLine("{0}: {1}", cultureName,
                           localDate.ToString(culture));
      }
   }
}
// The example displays the following output:
//       en-US: 6/19/2015 10:03:06 AM
//       en-GB: 19/06/2015 10:03:06
//       fr-FR: 19/06/2015 10:03:06
//       de-DE: 19.06.2015 10:03:06
//       ru-RU: 19.06.2015 10:03:06

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim localDate = DateTime.Now
      Dim cultureNames() As String = { "en-US", "en-GB", "fr-FR",
                                       "de-DE", "ru-RU" }

      For Each cultureName In cultureNames
         Dim culture As New CultureInfo(cultureName)
         Console.WriteLine("{0}: {1}", cultureName,
                           localDate.ToString(culture))
      Next
   End Sub
End Module
' The example displays the following output:
'    en-US: 6/19/2015 10:03:06 AM
'    en-GB: 19/06/2015 10:03:06
'    fr-FR: 19/06/2015 10:03:06
'    de-DE: 19.06.2015 10:03:06
'    ru-RU: 19.06.2015 10:03:06

這個屬性的解決方式取決於系統計時器，這取決於基礎作業系統。它通常會介於0.5 到15毫秒之間。因此， Now 在短時間間隔內（例如在迴圈中）重複呼叫屬性，可能會傳回相同的值。

Now屬性經常用來測量效能。不過，由於其低解析度，因此不適合作為效能評定工具使用。更好的替代方式是使用 Stopwatch 類別。

從 .NET Framework 版本2.0 開始，傳回值是其屬性會傳回的 DateTime Kind DateTimeKind.Local 。

注意

您也可以使用 DateTimeOffset.Now 屬性來取得目前的本機日期和時間。這可讓本地時間以明確的方式表示為單一時間點，進而讓該時間值可在電腦之間移植。

適用於

另請參閱

Now
UtcNow

DateTime.Now 屬性

定義

屬性值

範例

備註

適用於

另請參閱

其他資源