Directory.SetLastWriteTime(String, DateTime) 方法

定义

命名空间:

System.IO

程序集:

System.Runtime.dll

Source:

Directory.cs

设置上次写入目录的日期和时间。

public:
 static void SetLastWriteTime(System::String ^ path, DateTime lastWriteTime);

public static void SetLastWriteTime (string path, DateTime lastWriteTime);

static member SetLastWriteTime : string * DateTime -> unit

Public Shared Sub SetLastWriteTime (path As String, lastWriteTime As DateTime)

参数

path

String

目录的路径。

lastWriteTime

DateTime

上次写入目录的日期和时间。 该值用本地时间表示。

例外

FileNotFoundException

找不到 path（例如，目录不存在或在未映射的驱动器上）。

DirectoryNotFoundException

找不到 path（例如，目录不存在或在未映射的驱动器上）。

ArgumentException

.NET Framework 和 2.1 之前的 .NET Core 版本：path是一个零长度字符串，仅包含空格，或者包含一个或多个无效字符。 你可以使用 GetInvalidPathChars() 方法查询无效字符。

ArgumentNullException

path 为 null。

PathTooLongException

指定的路径和/或文件名超过了系统定义的最大长度。

UnauthorizedAccessException

调用方没有所要求的权限。

PlatformNotSupportedException

当前操作系统不是 Windows NT 或更高版本。

ArgumentOutOfRangeException

lastWriteTime 指定一个超出该操作允许的日期或时间范围的值。

示例

以下示例演示如何使用 SetLastWriteTime。

using namespace System;
using namespace System::IO;
void main()
{
   try
   {
      String^ path = "c:\\MyDir";
      if (  !Directory::Exists( path ) )
      {
         Directory::CreateDirectory( path );
      }
      else
      {
         
         // Take an action that will affect the write time.
         Directory::SetLastWriteTime( path, DateTime(1985,4,3) );
      }
      
      // Get the last write time of a well-known directory.
      DateTime dt = Directory::GetLastWriteTime( path );
      Console::WriteLine( "The last write time for this directory was {0}", dt );
      
      //Update the last write time.
      Directory::SetLastWriteTime( path, DateTime::Now );
      dt = Directory::GetLastWriteTime( path );
      Console::WriteLine( "The last write time for this directory was {0}", dt );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "The process failed: {0}", e );
   }

}

using System;
using System.IO;

class Test
{
    public static void Main()
    {
        try
        {
            string path = @"c:\MyDir";
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(path);
            }
            else
            {
                // Take an action that will affect the write time.
                Directory.SetLastWriteTime(path, new DateTime(1985,4,3));
            }

            // Get the last write time of a well-known directory.
            DateTime dt = Directory.GetLastWriteTime(path);
            Console.WriteLine("The last write time for this directory was {0}", dt);
            
            //Update the last write time.
            Directory.SetLastWriteTime(path, DateTime.Now);
            dt = Directory.GetLastWriteTime(path);
            Console.WriteLine("The last write time for this directory was {0}", dt);
        }
        catch (Exception e)
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }
    }
}

open System
open System.IO

try
    let path = @"c:\MyDir"
    if not (Directory.Exists path) then
        Directory.CreateDirectory path |> ignore

    else
        // Take an action that will affect the write time.
        Directory.SetLastWriteTime(path, DateTime(1985, 4, 3))

    // Get the last write time of a well-known directory.
    let dt = Directory.GetLastWriteTime path
    printfn $"The last write time for this directory was {dt}"
    
    //Update the last write time.
    Directory.SetLastWriteTime(path, DateTime.Now)
    let dt = Directory.GetLastWriteTime path
    printfn $"The last write time for this directory was {dt}"
with e ->
    printfn $"The process failed: {e}"

Imports System.IO

Public Class Test
    Public Shared Sub Main()
        Try
            Dim path As String = "c:\MyDir"
            If Directory.Exists(path) = False Then
                Directory.CreateDirectory(path)
            Else
                ' Take an action that will affect the write time.
                Directory.SetLastWriteTime(path, New DateTime(1985, 4, 3))
            End If

            'Get the last write time of a well-known directory.
            Dim dt As DateTime = Directory.GetLastWriteTime(path)
            Console.WriteLine("The last write time for this directory was {0}", dt)

            'Update the last write time.
            Directory.SetLastWriteTime(path, DateTime.Now)
            dt = Directory.GetLastWriteTime(path)
            Console.WriteLine("The last write time for this directory was {0}", dt)

        Catch e As Exception
            Console.WriteLine("The process failed: {0}", e.ToString())
        End Try
    End Sub
End Class

注解

允许 path 参数指定相对或绝对路径信息。 相对路径信息解释为相对于当前工作目录。 若要获取当前工作目录，请参阅 GetCurrentDirectory。

参数的 path 区分大小写对应于运行代码的文件系统的区分大小写。 例如，它在 NTFS 上不区分大小写， (默认 Windows 文件系统) ，Linux 文件系统上区分大小写。

有关常见 I/O 任务的列表，请参阅 常见 I/O 任务。

另请参阅

• FileSystemWatcher
• 文件和流 I/O
• 如何：从文件中读取文本
• 如何：将文本写入文件