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FileSystemInfo.LastAccessTime Property

Gets or sets the time the current file or directory was last accessed.

Namespace:  System.IO
Assembly:  mscorlib (in mscorlib.dll)

public DateTime LastAccessTime { get; set; }

Property Value

Type: System.DateTime
The time that the current file or directory was last accessed.

ExceptionCondition
IOException

Refresh cannot initialize the data.

PlatformNotSupportedException

The current operating system is not Windows NT or later.

ArgumentOutOfRangeException

The caller attempts to set an invalid access time

Note   This method may return an inaccurate value, because it uses native functions whose values may not be continuously updated by the operating system.

If the file described in the FileSystemInfo object does not exist, this property will return 12:00 midnight, January 1, 1601 A.D. (C.E.) Coordinated Universal Time (UTC), adjusted to local time.

The value of the LastAccessTimeUtc property is pre-cached if the current instance of the FileSystemInfo object was returned from any of the following DirectoryInfo methods:

To get the latest value, call the Refresh method.

Windows 95, Windows 98, Windows 98 Second Edition Platform Note: These operating systems do not support this property, and DirectoryInfo implementations of this property are not supported.

The following code example demonstrates the updating of the LastAccessTime property through a "touch" operation. In this example, the file is "touched", updating the CreationTime, LastAccessTime and LastWriteTime properties to the current date and time.

using System;
using System.IO;

namespace touch
{
    class Touch
    {
        static void Main(string[] args)
        {
            // Make sure a filename was provided. 
            if (args.Length > 0)
            {
                // Verify that the provided filename exists. 
                if (File.Exists(args[0]))
                {
                    FileInfo fi = new FileInfo(args[0]);
                    touchFile(fi);
                }
                else
                {
                    Console.WriteLine(
                        "Could not find the file: {0}.", args[0]);
                }
            }
            else
            {
                Console.WriteLine("No file was specified.");
            }
        }

        static void touchFile(FileSystemInfo fsi)
        {
            Console.WriteLine("Touching: {0}", fsi.FullName);

            // Update the CreationTime, LastWriteTime and LastAccessTime. 
            try
            {
                fsi.CreationTime = fsi.LastWriteTime = fsi.LastAccessTime =
                    DateTime.Now;
            }
            catch (Exception e)
            {
                Console.WriteLine("Error: {0}", e.Message);
            }
        }
    }
}

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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