Directory.GetLastWriteTimeUtc(String) Método

Definição

Retorna a data e hora, no formato UTC (Tempo Universal Coordenado), em que o arquivo ou diretório especificado foi gravado pela última vez.Returns the date and time, in Coordinated Universal Time (UTC) format, that the specified file or directory was last written to.

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

Parâmetros

path
String

O arquivo ou diretório para o qual obter informações de data e hora da modificação.The file or directory for which to obtain modification date and time information.

Retornos

DateTime

Uma estrutura que está definida para a data e hora em que o arquivo ou diretório especificado foi gravado pela última vez.A structure that is set to the date and time the specified file or directory was last written to. Esse valor é expresso em horário UTC.This value is expressed in UTC time.

Exceções

O chamador não tem a permissão necessária.The caller does not have the required permission.

path é uma cadeia de comprimento zero, contém somente espaços em branco ou um ou mais caracteres inválidos.path is a zero-length string, contains only white space, or contains one or more invalid characters. Consulte caracteres inválidos com o método GetInvalidPathChars().You can query for invalid characters with the GetInvalidPathChars() method.

path é null.path is null.

O caminho especificado, o nome de arquivo, ou ambos excedem o tamanho máximo definido pelo sistema.The specified path, file name, or both exceed the system-defined maximum length.

Exemplos

O exemplo a seguir ilustra as diferenças na saída ao usar a saída UTC (tempo Universal Coordenado).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

Comentários

Observação

Esse método pode retornar um valor impreciso, pois ele usa funções nativas cujos valores podem não ser atualizados continuamente pelo sistema operacional.This method may return an inaccurate value, because it uses native functions whose values may not be continuously updated by the operating system.

Se o diretório descrito no path parâmetro não existir, esse método retornará 12:00 meia-noite, 1º de janeiro de 1601 d.c.If the directory described in the path parameter does not exist, this method returns 12:00 midnight, January 1, 1601 A.D. (C.E.) Tempo Universal Coordenado (UTC).(C.E.) Coordinated Universal Time (UTC).

Para obter uma lista de tarefas comuns de e/s, consulte tarefas comuns de e/s.For a list of common I/O tasks, see Common I/O Tasks.

Aplica-se a

Confira também