Directory.GetLastWriteTimeUtc(String) Metode

Definisi

Ruang nama:

System.IO

Rakitan:

System.Runtime.dll

Sumber:

Directory.cs

Mengembalikan tanggal dan waktu, dalam format Waktu Universal Terkoordinasi (UTC), yang terakhir ditulis oleh file atau direktori yang ditentukan.

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

Parameter

path

String

File atau direktori untuk mendapatkan informasi tanggal dan waktu modifikasi.

Mengembalikan

DateTime

Struktur yang diatur ke tanggal dan waktu file atau direktori yang ditentukan terakhir ditulis. Nilai ini dinyatakan dalam waktu UTC.

Pengecualian

UnauthorizedAccessException

Pemanggil tidak memiliki izin yang diperlukan.

ArgumentException

versi .NET Framework dan .NET Core yang lebih lama dari 2.1: path adalah string panjang nol, hanya berisi spasi kosong, atau berisi satu atau beberapa karakter yang tidak valid. Anda dapat mengkueri karakter yang GetInvalidPathChars() tidak valid dengan metode .

ArgumentNullException

pathadalah null.

PathTooLongException

Jalur yang ditentukan, nama file, atau keduanya melebihi panjang maksimum yang ditentukan sistem.

Contoh

Contoh berikut mengilustrasikan perbedaan output saat menggunakan output Waktu Universal Terkoordinasi (UTC).

// 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.
open System
open System.IO

// Set the directory.
let n = @"C:\test\newdir"
//Create two variables to use to set the time.
let dtime1 = DateTime(2002, 1, 3)
let dtime2 = DateTime(1999, 1, 1)

//Create the directory.
try
    Directory.CreateDirectory n |> ignore
with :? IOException as e ->
    printfn $"{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.
printfn $"Creation Date: {Directory.GetCreationTime n}"
printfn $"UTC creation Date: {Directory.GetCreationTimeUtc n}"
printfn $"Last write time: {Directory.GetLastWriteTime n}"
printfn $"UTC last write time: {Directory.GetLastWriteTimeUtc n}"
printfn $"Last access time: {Directory.GetLastAccessTime n}"
printfn $"UTC last access time: {Directory.GetLastAccessTimeUtc n}"

//Set the last write time to a different value.
Directory.SetLastWriteTimeUtc(n, dtime2)
printfn $"Changed last write time: {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

Keterangan

Catatan

Metode ini dapat mengembalikan nilai yang tidak akurat, karena menggunakan fungsi asli yang nilainya mungkin tidak terus diperbarui oleh sistem operasi.

Jika direktori yang dijelaskan dalam path parameter tidak ada, metode ini mengembalikan 12:00 tengah malam, 1 Januari 1601 A.D. (C.E.) Waktu Universal Terkoordinasi (UTC).

Untuk daftar tugas I/O umum, lihat Tugas I/O Umum.

Lihat juga

• FileSystemWatcher
• I/O File dan Aliran
• Cara: Membaca Teks dari File
• Cara: Menulis Teks ke File