Home Library Learn Downloads Support Community
Sign in | United States - English | |
1 out of 5 rated this helpful - Rate this topic

File.SetAttributes Method

.NET Framework 4

Updated: October 2010

Sets the specified FileAttributes of the file on the specified path.

Namespace:  System.IO
Assembly:  mscorlib (in mscorlib.dll)
C#
C++
F#
VB
Copy 
public static void SetAttributes(
	string path,
	FileAttributes fileAttributes
)

Parameters

path
Type: System.String
The path to the file.
fileAttributes
Type: System.IO.FileAttributes
A bitwise combination of the enumeration values.
Exception Condition
ArgumentException

path is empty, contains only white spaces, contains invalid characters, or the file attribute is invalid.

PathTooLongException

The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters.

NotSupportedException

path is in an invalid format.

DirectoryNotFoundException

The specified path is invalid, (for example, it is on an unmapped drive).

FileNotFoundException

The file cannot be found.
UnauthorizedAccessException

path specified a file that is read-only.

-or-

This operation is not supported on the current platform.

-or-

path specified a directory.

-or-

The caller does not have the required permission.

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.

Certain file attributes, such as Hidden and ReadOnly, can be combined. Other attributes, such as Normal, must be used alone.

It is not possible to change the compression status of a File object using the SetAttributes method.

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

The following example demonstrates the GetAttributes and SetAttributes methods by applying the Archive and Hidden attributes to a file.

C#
C++
VB
Copy 

using System;
using System.IO;
using System.Text;

class Test 
{
    public static void Main() 
    {
        string path = @"c:\temp\MyTest.txt";

        // Create the file if it exists.
        if (!File.Exists(path)) 
        {
            File.Create(path);
        }

        FileAttributes attributes = File.GetAttributes(path);

        if ((attributes & FileAttributes.Hidden) == FileAttributes.Hidden)
        {
            // Show the file.
            attributes = RemoveAttribute(attributes, FileAttributes.Hidden);
            File.SetAttributes(path, attributes);
            Console.WriteLine("The {0} file is no longer hidden.", path);
        } 
        else 
        {
            // Hide the file.
            File.SetAttributes(path, File.GetAttributes(path) | FileAttributes.Hidden);
            Console.WriteLine("The {0} file is now hidden.", path);
        }
    }

    private static FileAttributes RemoveAttribute(FileAttributes attributes, FileAttributes attributesToRemove)
    {
        return attributes & ~attributesToRemove;
    }
}

.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

Date

History

Reason

October 2010

Changed example to correctly remove attributes.

Customer feedback.
Did you find this helpful?
(1500 characters remaining)
Community Content Add
Annotations FAQ
Set compression status of a File object

You can use DeviceIoControl interop:

    internal static class NativeMethods
    {
        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        public static extern int DeviceIoControl(
            SafeFileHandle hDevice,
            int dwIoControlCode,
            ref short lpInBuffer,
            int nInBufferSize,
            IntPtr lpOutBuffer,
            int nOutBufferSize,
            ref int lpBytesReturned,
            IntPtr lpOverlapped);
    }

public class SomeClass {

        public static void SetCompressionAttribute(string output)
        {
            using (FileStream outputStream = File.Create(output))
            {
                // Write to file

                // Setting compression flag
                const int SetCompressionCode = 0x9C040;
                const short CompressionFormatDefault = 1;
                int bytesReturned = 0;
                short inputBuffer = CompressionFormatDefault;

                int result = NativeMethods.DeviceIoControl(
                    outputStream.SafeFileHandle,
                    SetCompressionCode,
                    ref inputBuffer,
                    sizeof(short),
                    IntPtr.Zero,
                    0,
                    ref bytesReturned,
                    IntPtr.Zero);

                if (result == 0)
                {
                    Marshal.ThrowExceptionForHR(Marshal.GetLastWin32Error());
                }
            }
        }
}

History
Misleading info in Exceptions
Note that the guidelines in UnauthorizedAccessException are misleading - it seems to suggest that if a file is read-only, that you cannot change its attributes.  This is not correct; in fact, this is expected if you are trying to delete a read-only file.  You need to first change the attribs to Normal, then delete it. $0$0 $0 $0Also, there's a typo in the example:$0 $0$0 $0 $0 $0// Create the file if it doesn't exist$0 $0
History