Directory.SetLastWriteTimeUtc メソッドとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

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Directory.SetLastWriteTimeUtc メソッド

ディレクトリに最後に書き込んだ日付と時刻を世界協定時刻 (UTC) 形式で設定します。

名前空間: System.IO
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

Public Shared Sub SetLastWriteTimeUtc
 ( _
    path As String, _
    lastWriteTimeUtc As DateTime _
)

Visual Basic (使用法)

Dim path As String
Dim lastWriteTimeUtc As DateTime

Directory.SetLastWriteTimeUtc(path, lastWriteTimeUtc)

public static void SetLastWriteTimeUtc
 (
    string path,
    DateTime lastWriteTimeUtc
)

C++

public:
static void SetLastWriteTimeUtc (
    String^ path, 
    DateTime lastWriteTimeUtc
)

public static void SetLastWriteTimeUtc
 (
    String path, 
    DateTime lastWriteTimeUtc
)

JScript

public static function SetLastWriteTimeUtc
 (
    path : String, 
    lastWriteTimeUtc : DateTime
)

パラメータ

path: ディレクトリのパス。

lastWriteTimeUtc: ディレクトリに最後に書き込んだ日付と時刻。この値は UTC 時刻で表現されます。

例外

例外の種類	条件
FileNotFoundException	指定したパスが見つかりませんでした。
ArgumentException	path が、長さが 0 の文字列であるか、空白しか含んでいないか、または InvalidPathChars で定義されている無効な文字を 1 つ以上含んでいます。
ArgumentNullException	path が null 参照 (Visual Basic では Nothing) です。
PathTooLongException	指定したパス、ファイル名、またはその両方がシステム定義の最大長を超えています。たとえば、Windows ベースのプラットフォームの場合、パスの長さは 248 文字未満、ファイル名の長さは 260 文字未満である必要があります。
UnauthorizedAccessException	呼び出し元に、必要なアクセス許可がありません。
PlatformNotSupportedException	現在のオペレーティングシステムは Microsoft Windows NT 以降ではありません。
ArgumentOutOfRangeException	lastWriteTimeUtc は、この操作で許可される日付または時刻の範囲を超える値を指定します。

解説

path パラメータは、相対パス情報または絶対パス情報を指定することを許可されています。相対パス情報は、現在の作業ディレクトリに対して相対的に解釈されます。現在の作業ディレクトリを取得するには、GetCurrentDirectory のトピックを参照してください。

path パラメータでは大文字と小文字が区別されません。

その他の一般的な I/O タスクまたは関連する I/O タスクの例を次の表に示します。

実行するタスク	参考例があるトピック
テキストファイルを作成する。	方法 : ファイルにテキストを書き込む
テキストファイルに書き込む。	方法 : ファイルにテキストを書き込む
テキストファイルから読み取る。	方法 : ファイルからテキストを読み取る
ディレクトリを削除する。	Delete Delete
ディレクトリ内のサブディレクトリを参照する。	GetDirectories GetDirectories
ディレクトリのサイズを取得する。	Directory

Windows 95, Windows 98, Windows 98 Second Edition プラットフォームメモ : これらのオペレーティングシステムではこのメソッドはサポートされません。

使用例

世界協定時刻 (UTC) を使用した場合の出力の違いを、次のコード例に示します。

Visual Basic

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

' 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

C++

// 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.
import System.*;
import System.IO.*;

public class DirectoryUTCTime
{
    public static void main(String[]
 args)
    {
        // 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));
    } //main
} //DirectoryUTCTime
// 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