File.SetLastAccessTime(String, DateTime) 方法

  • 参考

定义

命名空间:
System.IO
程序集:
mscorlib.dll, System.IO.FileSystem.dll
程序集:
System.IO.FileSystem.dll
程序集:
System.Runtime.dll
程序集:
netstandard.dll
程序集:
mscorlib.dll

设置上次访问指定文件的日期和时间。

public:
 static void SetLastAccessTime(System::String ^ path, DateTime lastAccessTime);
public static void SetLastAccessTime (string path, DateTime lastAccessTime);
static member SetLastAccessTime : string * DateTime -> unit
Public Shared Sub SetLastAccessTime (path As String, lastAccessTime As DateTime)

参数

path
String

要设置其访问日期和时间信息的文件。

lastAccessTime
DateTime

一个 DateTime，它包含要为 path 的上次访问日期和时间设置的值。 该值用本地时间表示。

例外

ArgumentException

.NET Framework 和 .net Core 版本早于2.1： path 是一个长度为零的字符串，仅包含空格，或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。

FileNotFoundException

未找到指定路径。

UnauthorizedAccessException

调用方没有所要求的权限。

NotSupportedException

path 的格式无效。

ArgumentOutOfRangeException

lastAccessTime 指定一个超出该操作允许的日期或时间范围的值。

示例

下面的示例将检查指定文件的文件系统（如有必要），然后设置并获取上次访问时间。

using namespace System;
using namespace System::IO;
int main()
{
   try
   {
      String^ path = "c:\\Temp\\MyTest.txt";
      if (  !File::Exists( path ) )
      {
         File::Create( path );
         
         // Update the last access time.    
      }
      File::SetLastAccessTime( path, DateTime(1985,5,4) );
      
      // Get the creation time of a well-known directory.
      DateTime dt = File::GetLastAccessTime( path );
      Console::WriteLine( "The last access time for this file was {0}.", dt );
      
      // Update the last access time.
      File::SetLastAccessTime( path, DateTime::Now );
      dt = File::GetLastAccessTime( path );
      Console::WriteLine( "The last access time for this file 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:\Temp\MyTest.txt";

            if (!File.Exists(path))
            {
                File.Create(path);
                // Update the last access time.	
            }
            File.SetLastAccessTime(path, new DateTime(1985,5,4));

            // Get the creation time of a well-known directory.
            DateTime dt = File.GetLastAccessTime(path);
            Console.WriteLine("The last access time for this file was {0}.", dt);
            
            // Update the last access time.
            File.SetLastAccessTime(path, DateTime.Now);
            dt = File.GetLastAccessTime(path);
            Console.WriteLine("The last access time for this file was {0}.", dt);
        }
        catch (Exception e)
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }
    }
}

Imports System.IO
Imports System.Text

Public Class Test
    Public Shared Sub Main()
        Try
            Dim path As String = "c:\Temp\MyTest.txt"

            If File.Exists(path) = False Then
                File.Create(path)
            End If
            File.SetLastAccessTime(path, New DateTime(1985, 5, 4))

            ' Get the creation time of a well-known directory.
            Dim dt As DateTime = File.GetLastAccessTime(path)
            Console.WriteLine("The last access time for this file was {0}.", dt)

            ' Update the last access time.
            File.SetLastAccessTime(path, DateTime.Now)
            dt = File.GetLastAccessTime(path)
            Console.WriteLine("The last access time for this file was {0}.", dt)

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

注解

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

有关常见 i/o 任务的列表，请参阅 常见 I/o 任务。

适用于

另请参阅