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DateTime.Now 属性
参考
定义
命名空间:
System
程序集:System.Runtime.dll
程序集:mscorlib.dll
程序集:netstandard.dll
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。 获取一个 DateTime 对象，该对象设置为此计算机上的当前日期和时间，表示为本地时间。 public: static property DateTime Now { DateTime get(); }; public static DateTime Now { get; } static member Now : DateTime Public Shared ReadOnly Property Now As DateTime 属性值 DateTime其值为当前日期和时间的对象。 示例以下示例使用 Now 和 UtcNow 属性检索当前本地日期和时间，以及当前通用协调 (UTC) 日期和时间。 然后，它使用多个区域性的格式设置约定来显示字符串及其属性的值 Kind 。 using namespace System; using namespace System::Globalization; void main() { DateTime localDate = DateTime::Now; DateTime utcDate = DateTime::UtcNow; array^ 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 open System open System.Globalization let localDate = DateTime.Now let utcDate = DateTime.UtcNow let cultureNames = [ "en-US"; "en-GB"; "fr-FR"; "de-DE"; "ru-RU" ] for cultureName in cultureNames do let culture = CultureInfo cultureName printfn $"{culture.NativeName}:" printfn $" Local date and time: {localDate.ToString culture}, {localDate.Kind:G}" printfn $" UTC date and time: {utcDate.ToString culture}, {utcDate.Kind:G}\n" // 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 注解属性 Now 返回一个 DateTime 值，该值表示本地计算机上的当前日期和时间。 请注意，值（表示自 0001 年 1 月 1 日午夜以来经过的计时周期数）与该值DateTime的字符串表示形式（以特定于区域性的格式表示日期和时间值）之间存在DateTime差异。 有关设置日期和时间值格式的信息，请参阅 ToString 方法。 以下示例以许多特定于区域性的格式显示短日期和时间字符串。 using namespace System; using namespace System::Globalization; void main() { DateTime localDate = DateTime::Now; array^ 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 open System open System.Globalization let localDate = DateTime.Now let cultureNames = [ "en-US"; "en-GB"; "fr-FR"; "de-DE"; "ru-RU" ] for cultureName in cultureNames do let culture = CultureInfo cultureName printfn $"{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此属性的解析取决于系统计时器，后者取决于基础操作系统。 它往往介于 0.5 到 15 毫秒之间。 因此，在短时间间隔内（例如在循环中）对 属性的重复调用 Now 可能会返回相同的值。 属性 Now 通常用于度量性能。 但是，由于分辨率较低，它不适合用作基准测试工具。 更好的替代方法是使用 Stopwatch 类。 从 .NET Framework 2.0 版开始，返回值为 ，DateTime其 Kind 属性返回 DateTimeKind.Local。 注意 还可以使用 DateTimeOffset.Now 属性检索当前本地日期和时间。 它允许将本地时间明确表示为单个时间点，从而使该时间值在计算机之间可移植。 适用于 另请参阅 Now UtcNow |
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