Directory.SetLastWriteTime(String, DateTime) Method

Reference

Definition

Namespace:: System.IO

Assemblies:: mscorlib.dll, System.IO.FileSystem.dll

Assemblies:: netstandard.dll, System.Runtime.dll

Assemblies:: netstandard.dll, System.IO.FileSystem.dll

Assemblies:: netstandard.dll, System.IO.FileSystem.dll, System.Runtime.dll

Assembly:: System.IO.FileSystem.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: Directory.cs

Source:: Directory.cs

Source:: Directory.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Sets the date and time a directory was last written to.

public:
 static void SetLastWriteTime(System::String ^ path, DateTime lastWriteTime);

public static void SetLastWriteTime(string path, DateTime lastWriteTime);

static member SetLastWriteTime : string * DateTime -> unit

Public Shared Sub SetLastWriteTime (path As String, lastWriteTime As DateTime)

Parameters

path: String

The path of the directory.

lastWriteTime: DateTime

The date and time the directory was last written to. This value is expressed in local time.

Exceptions

FileNotFoundException

path was not found (for example, the directory doesn't exist or it is on an unmapped drive).

DirectoryNotFoundException

path was not found (for example, the directory doesn't exist or it is on an unmapped drive).

ArgumentException

.NET Framework and .NET Core versions older than 2.1: path is a zero-length string, contains only white space, or contains one or more invalid characters. You can query for invalid characters with the GetInvalidPathChars() method.

ArgumentNullException

path is null.

PathTooLongException

The specified path, file name, or both exceed the system-defined maximum length.

UnauthorizedAccessException

The caller does not have the required permission.

PlatformNotSupportedException

The current operating system is not Windows NT or later.

ArgumentOutOfRangeException

lastWriteTime specifies a value outside the range of dates or times permitted for this operation.

Examples

The following example demonstrates how to use SetLastWriteTime.

using namespace System;
using namespace System::IO;
void main()
{
   try
   {
      String^ path = "c:\\MyDir";
      if (  !Directory::Exists( path ) )
      {
         Directory::CreateDirectory( path );
      }
      else
      {
         
         // Take an action that will affect the write time.
         Directory::SetLastWriteTime( path, DateTime(1985,4,3) );
      }
      
      // Get the last write time of a well-known directory.
      DateTime dt = Directory::GetLastWriteTime( path );
      Console::WriteLine( "The last write time for this directory was {0}", dt );
      
      //Update the last write time.
      Directory::SetLastWriteTime( path, DateTime::Now );
      dt = Directory::GetLastWriteTime( path );
      Console::WriteLine( "The last write time for this directory 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:\MyDir";
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(path);
            }
            else
            {
                // Take an action that will affect the write time.
                Directory.SetLastWriteTime(path, new DateTime(1985,4,3));
            }

            // Get the last write time of a well-known directory.
            DateTime dt = Directory.GetLastWriteTime(path);
            Console.WriteLine("The last write time for this directory was {0}", dt);
            
            //Update the last write time.
            Directory.SetLastWriteTime(path, DateTime.Now);
            dt = Directory.GetLastWriteTime(path);
            Console.WriteLine("The last write time for this directory was {0}", dt);
        }
        catch (Exception e)
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }
    }
}

open System
open System.IO

try
    let path = @"c:\MyDir"
    if not (Directory.Exists path) then
        Directory.CreateDirectory path |> ignore

    else
        // Take an action that will affect the write time.
        Directory.SetLastWriteTime(path, DateTime(1985, 4, 3))

    // Get the last write time of a well-known directory.
    let dt = Directory.GetLastWriteTime path
    printfn $"The last write time for this directory was {dt}"
    
    //Update the last write time.
    Directory.SetLastWriteTime(path, DateTime.Now)
    let dt = Directory.GetLastWriteTime path
    printfn $"The last write time for this directory was {dt}"
with e ->
    printfn $"The process failed: {e}"

Imports System.IO

Public Class Test
    Public Shared Sub Main()
        Try
            Dim path As String = "c:\MyDir"
            If Directory.Exists(path) = False Then
                Directory.CreateDirectory(path)
            Else
                ' Take an action that will affect the write time.
                Directory.SetLastWriteTime(path, New DateTime(1985, 4, 3))
            End If

            'Get the last write time of a well-known directory.
            Dim dt As DateTime = Directory.GetLastWriteTime(path)
            Console.WriteLine("The last write time for this directory was {0}", dt)

            'Update the last write time.
            Directory.SetLastWriteTime(path, DateTime.Now)
            dt = Directory.GetLastWriteTime(path)
            Console.WriteLine("The last write time for this directory was {0}", dt)

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

Remarks

The path parameter is permitted to specify relative or absolute path information. Relative path information is interpreted as relative to the current working directory. To obtain the current working directory, see GetCurrentDirectory.

The case-sensitivity of the path parameter corresponds to that of the file system on which the code is running. For example, it's case-insensitive on NTFS (the default Windows file system) and case-sensitive on Linux file systems.

For a list of common I/O tasks, see Common I/O Tasks.

Applies to

Product	Versions
.NET	Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	1.3, 1.4, 1.6, 2.0, 2.1
UWP	10.0

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