Directory.GetLastAccessTimeUtc(String) Metoda

Definicja

Zwraca datę i godzinę w formacie uniwersalnego czasu koordynowanego (UTC), do ostatniego dostępu do określonego pliku lub katalogu.Returns the date and time, in Coordinated Universal Time (UTC) format, that the specified file or directory was last accessed.

public:
 static DateTime GetLastAccessTimeUtc(System::String ^ path);
public static DateTime GetLastAccessTimeUtc (string path);
static member GetLastAccessTimeUtc : string -> DateTime
Public Shared Function GetLastAccessTimeUtc (path As String) As DateTime

Parametry

path
String

Plik lub katalog, dla którego ma zostać uzyskany dostęp do informacji o dacie i godzinie.The file or directory for which to obtain access date and time information.

Zwraca

Struktura, która jest ustawiona na datę i godzinę ostatniego dostępu do określonego pliku lub katalogu.A structure that is set to the date and time the specified file or directory was last accessed. Ta wartość jest wyrażona w czasie UTC.This value is expressed in UTC time.

Wyjątki

Element wywołujący nie ma wymaganego uprawnienia.The caller does not have the required permission.

path jest ciągiem o zerowej długości, zawiera tylko znak odstępu lub zawiera jeden lub więcej nieprawidłowych znaków.path is a zero-length string, contains only white space, or contains one or more invalid characters. Za pomocą metody GetInvalidPathChars() można wykonywać zapytania dotyczące nieprawidłowych znaków.You can query for invalid characters with the GetInvalidPathChars() method.

Parametr path ma wartość null.path is null.

Podana ścieżka, nazwa pliku lub obie przekraczają maksymalną długość zdefiniowaną przez system.The specified path, file name, or both exceed the system-defined maximum length.

Parametr path ma nieprawidłowy format.The path parameter is in an invalid format.

Przykłady

Poniższy przykład ilustruje różnice w danych wyjściowych przy użyciu danych wyjściowych uniwersalnego czasu koordynowanego (UTC).The following example illustrates the differences in output when using Coordinated Universal Time (UTC) output.

// This sample shows the differences between dates from methods that use
//coordinated universal time (UTC) format and those that do not.
using namespace System;
using namespace System::IO;
int main()
{
   
   // Set the directory.
   String^ n = "C:\\test\\newdir";
   
   //Create two variables to use to set the time.
   DateTime dtime1 = DateTime(2002,1,3);
   DateTime dtime2 = DateTime(1999,1,1);
   
   //Create the directory.
   try
   {
      Directory::CreateDirectory( n );
   }
   catch ( IOException^ e ) 
   {
      Console::WriteLine( e );
   }

   
   //Set the creation and last access times to a variable DateTime value.
   Directory::SetCreationTime( n, dtime1 );
   Directory::SetLastAccessTimeUtc( n, dtime1 );
   
   // Print to console the results.
   Console::WriteLine( "Creation Date: {0}", Directory::GetCreationTime( n ) );
   Console::WriteLine( "UTC creation Date: {0}", Directory::GetCreationTimeUtc( n ) );
   Console::WriteLine( "Last write time: {0}", Directory::GetLastWriteTime( n ) );
   Console::WriteLine( "UTC last write time: {0}", Directory::GetLastWriteTimeUtc( n ) );
   Console::WriteLine( "Last access time: {0}", Directory::GetLastAccessTime( n ) );
   Console::WriteLine( "UTC last access time: {0}", Directory::GetLastAccessTimeUtc( n ) );
   
   //Set the last write time to a different value.
   Directory::SetLastWriteTimeUtc( n, dtime2 );
   Console::WriteLine( "Changed last write time: {0}", Directory::GetLastWriteTimeUtc( n ) );
}

// Obviously, since this sample deals with dates and times, the output will vary
// depending on when you run the executable. Here is one example of the output:
//Creation Date: 1/3/2002 12:00:00 AM
//UTC creation Date: 1/3/2002 8:00:00 AM
//Last write time: 12/31/1998 4:00:00 PM
//UTC last write time: 1/1/1999 12:00:00 AM
//Last access time: 1/2/2002 4:00:00 PM
//UTC last access time: 1/3/2002 12:00:00 AM
//Changed last write time: 1/1/1999 12:00:00 AM
// This sample shows the differences between dates from methods that use
//coordinated universal time (UTC) format and those that do not.
using System;
using System.IO;

namespace IOSamples
{
  public class DirectoryUTCTime
  {
    public static void Main()
    {
    // Set the directory.
      string n = @"C:\test\newdir";
        //Create two variables to use to set the time.
      DateTime dtime1 = new DateTime(2002, 1, 3);
      DateTime dtime2 = new DateTime(1999, 1, 1);

    //Create the directory.
      try
      {
          Directory.CreateDirectory(n);
      }
      catch (IOException e)
      {
          Console.WriteLine(e);
      }

    //Set the creation and last access times to a variable DateTime value.
      Directory.SetCreationTime(n, dtime1);
      Directory.SetLastAccessTimeUtc(n, dtime1);

        // Print to console the results.
      Console.WriteLine("Creation Date: {0}", Directory.GetCreationTime(n));
      Console.WriteLine("UTC creation Date: {0}", Directory.GetCreationTimeUtc(n));
      Console.WriteLine("Last write time: {0}", Directory.GetLastWriteTime(n));
      Console.WriteLine("UTC last write time: {0}", Directory.GetLastWriteTimeUtc(n));
      Console.WriteLine("Last access time: {0}", Directory.GetLastAccessTime(n));
      Console.WriteLine("UTC last access time: {0}", Directory.GetLastAccessTimeUtc(n));

        //Set the last write time to a different value.
      Directory.SetLastWriteTimeUtc(n, dtime2);
      Console.WriteLine("Changed last write time: {0}", Directory.GetLastWriteTimeUtc(n));
    }
  }
}
// Obviously, since this sample deals with dates and times, the output will vary
// depending on when you run the executable. Here is one example of the output:
//Creation Date: 1/3/2002 12:00:00 AM
//UTC creation Date: 1/3/2002 8:00:00 AM
//Last write time: 12/31/1998 4:00:00 PM
//UTC last write time: 1/1/1999 12:00:00 AM
//Last access time: 1/2/2002 4:00:00 PM
//UTC last access time: 1/3/2002 12:00:00 AM
//Changed last write time: 1/1/1999 12:00:00 AM

' This sample shows the differences between dates from methods that use
'coordinated universal time (UTC) format and those that do not.
Imports System.IO



Public Class DirectoryUTCTime
   
   Public Shared Sub Main()
      ' Set the directory.
      Dim n As String = "C:\test\newdir"
      'Create two variables to use to set the time.
      Dim dtime1 As New DateTime(2002, 1, 3)
      Dim dtime2 As New DateTime(1999, 1, 1)
      
      'Create the directory.
      Try
         Directory.CreateDirectory(n)
      Catch e As IOException
         Console.WriteLine(e)
      End Try
      
      'Set the creation and last access times to a variable DateTime value.
      Directory.SetCreationTime(n, dtime1)
      Directory.SetLastAccessTimeUtc(n, dtime1)
      
      ' Print to console the results.
      Console.WriteLine("Creation Date: {0}", Directory.GetCreationTime(n))
      Console.WriteLine("UTC creation Date: {0}", Directory.GetCreationTimeUtc(n))
      Console.WriteLine("Last write time: {0}", Directory.GetLastWriteTime(n))
      Console.WriteLine("UTC last write time: {0}", Directory.GetLastWriteTimeUtc(n))
      Console.WriteLine("Last access time: {0}", Directory.GetLastAccessTime(n))
      Console.WriteLine("UTC last access time: {0}", Directory.GetLastAccessTimeUtc(n))
      
      'Set the last write time to a different value.
      Directory.SetLastWriteTimeUtc(n, dtime2)
      Console.WriteLine("Changed last write time: {0}", Directory.GetLastWriteTimeUtc(n))
   End Sub
End Class

' Since this sample deals with dates and times, the output will vary
' depending on when you run the executable. Here is one example of the output:

' Creation Date: 1/3/2002 12:00:00 AM
' UTC creation Date: 1/3/2002 8:00:00 AM
' Last write time: 12/31/1998 4:00:00 PM
' UTC last write time: 1/1/1999 12:00:00 AM
' Last access time: 1/2/2002 4:00:00 PM
' UTC last access time: 1/3/2002 12:00:00 AM
' Changed last write time: 1/1/1999 12:00:00 AM

Uwagi

Uwaga

Ta metoda może zwracać niedokładną wartość, ponieważ używa funkcji natywnych, których wartości mogą nie być stale aktualizowane przez system operacyjny.This method may return an inaccurate value, because it uses native functions whose values may not be continuously updated by the operating system.

Jeśli katalog opisany w path parametr nie istnieje, ta metoda zwraca 12:00 północy, 1 stycznia 1601 N.E.If the directory described in the path parameter does not exist, this method returns 12:00 midnight, January 1, 1601 A.D. 0001 Uniwersalny czas koordynowany (UTC).(C.E.) Coordinated Universal Time (UTC).

Aby uzyskać listę typowych zadań we/wy, zobacz typowe zadania we/wy.For a list of common I/O tasks, see Common I/O Tasks.

Zabezpieczenia

FileIOPermission
do odczytywania określonego pliku lub katalogu.for reading the specified file or directory. Skojarzone Wyliczenie: ReadAssociated enumeration: Read

Dotyczy

Zobacz też