File​Info Class

Definition

Provides properties and instance methods for the creation, copying, deletion, moving, and opening of files, and aids in the creation of FileStream objects. This class cannot be inherited.

[System.Runtime.InteropServices.ComVisible(true)]
public sealed class FileInfo : System.IO.FileSystemInfo
Inheritance
Attributes

Inherited Members

System.IO.FileSystemInfo

System.Object

Examples

The following example demonstrates some of the main members of the FileInfo class.

When the properties are first retrieved, FileInfo calls the Refresh method and caches information about the file. On subsequent calls, you must call Refresh to get the latest copy of the information.

using namespace System;
using namespace System::IO;

int main()
{
   String^ path = Path::GetTempFileName();
   FileInfo^ fi1 = gcnew FileInfo( path );
   //Create a file to write to.
   StreamWriter^ sw = fi1->CreateText();
   try
   {
	 sw->WriteLine( "Hello" );
	 sw->WriteLine( "And" );
	 sw->WriteLine( "Welcome" );
   }
   finally
   {
	 if ( sw )
		delete (IDisposable^)sw;
   }

   //Open the file to read from.
   StreamReader^ sr = fi1->OpenText();
   try
   {
      String^ s = "";
      while ( s = sr->ReadLine() )
      {
         Console::WriteLine( s );
      }
   }
   finally
   {
      if ( sr )
         delete (IDisposable^)sr;
   }

   try
   {
      String^ path2 = Path::GetTempFileName();
      FileInfo^ fi2 = gcnew FileInfo( path2 );

      //Ensure that the target does not exist.
      fi2->Delete();

      //Copy the file.
      fi1->CopyTo( path2 );
      Console::WriteLine( "{0} was copied to {1}.", path, path2 );

      //Delete the newly created file.
      fi2->Delete();
      Console::WriteLine( "{0} was successfully deleted.", path2 );
   }
   catch ( Exception^ e )
   {
      Console::WriteLine( "The process failed: {0}", e );
   }
}
using System;
using System.IO;

class Test 
{
	
    public static void Main() 
    {
        string path = Path.GetTempFileName();
        FileInfo fi1 = new FileInfo(path);

        //Create a file to write to.
        using (StreamWriter sw = fi1.CreateText()) 
        {
            sw.WriteLine("Hello");
            sw.WriteLine("And");
            sw.WriteLine("Welcome");
        }	

        //Open the file to read from.
        using (StreamReader sr = fi1.OpenText()) 
        {
            string s = "";
            while ((s = sr.ReadLine()) != null) 
            {
                Console.WriteLine(s);
            }
        }

        try 
        {
            string path2 = Path.GetTempFileName();
            FileInfo fi2 = new FileInfo(path2);

            //Ensure that the target does not exist.
            fi2.Delete();

            //Copy the file.
            fi1.CopyTo(path2);
            Console.WriteLine("{0} was copied to {1}.", path, path2);

            //Delete the newly created file.
            fi2.Delete();
            Console.WriteLine("{0} was successfully deleted.", path2);

        } 
        catch (Exception e) 
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }
    }
}
Imports System
Imports System.IO

Public Class Test

    Public Shared Sub Main()
        Dim path1 As String = Path.GetTempFileName()
        Dim path2 As String = Path.GetTempFileName()
        Dim fi As FileInfo = New FileInfo(path1)

        'Create a file to write to.
        Dim sw As StreamWriter = fi.CreateText()

        sw.WriteLine("Hello")
        sw.WriteLine("And")
        sw.WriteLine("Welcome")
        sw.Flush()
        sw.Close()

        Try
            'Open the file to read from.
            Dim sr As StreamReader = fi.OpenText()

            Do While sr.Peek() >= 0
                Console.WriteLine(sr.ReadLine())
            Loop
            sr.Close()
            Dim fi2 As FileInfo = New FileInfo(path2)

            'Ensure that the target does not exist.
            fi2.Delete()

            'Copy the file.
            fi.CopyTo(path2)
            Console.WriteLine("{0} was copied to {1}.", path1, path2)

            'Delete the newly created file.
            fi2.Delete()
            Console.WriteLine("{0} was successfully deleted.", path2)

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

This example produces output similar to the following.

Hello  
And  
Welcome  
C:\Users\userName\AppData\Local\Temp\tmp70AB.tmp was copied to C:\Users\userName\AppData\Local\Temp\tmp70CB.tmp.  
C:\Users\userName\AppData\Local\Temp\tmp70CB.tmp was successfully deleted.  

Remarks

Note

To view the .NET Framework source code for this type, see the Reference Source. You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions.

Use the FileInfo class for typical operations such as copying, moving, renaming, creating, opening, deleting, and appending to files.

If you are performing multiple operations on the same file, it can be more efficient to use FileInfo instance methods instead of the corresponding static methods of the File class, because a security check will not always be necessary.

Many of the FileInfo methods return other I/O types when you create or open files. You can use these other types to further manipulate a file. For more information, see specific FileInfo members such as Open, OpenRead, OpenText, CreateText, or Create.

By default, full read/write access to new files is granted to all users.

The following table describes the enumerations that are used to customize the behavior of various FileInfo methods.

Enumeration Description
FileAccess Specifies read and write access to a file.
FileShare Specifies the level of access permitted for a file that is already in use.
FileMode Specifies whether the contents of an existing file are preserved or overwritten, and whether requests to create an existing file cause an exception.
Note

In members that accept a path as an input string, that path must be well-formed or an exception is raised. For example, if a path is fully qualified but begins with a space, the path is not trimmed in methods of the class. Therefore, the path is malformed and an exception is raised. Similarly, a path or a combination of paths cannot be fully qualified twice. For example, "c:\temp c:\windows" also raises an exception in most cases. Ensure that your paths are well-formed when using methods that accept a path string.

In members that accept a path, the path can refer to a file or just a directory. The specified path can also refer to a relative path or a Universal Naming Convention (UNC) path for a server and share name. For example, all the following are acceptable paths:

  • "c:\\MyDir\\MyFile.txt" in C#, or "c:\MyDir\MyFile.txt" in Visual Basic.

  • "c:\\MyDir" in C#, or "c:\MyDir" in Visual Basic.

  • "MyDir\\MySubdir" in C#, or "MyDir\MySubDir" in Visual Basic.

  • "\\\\MyServer\\MyShare" in C#, or "\\MyServer\MyShare" in Visual Basic.

The FileInfo class provides the following properties that enable you to retrieve information about a file. For an example of how to use each property, see the property pages.

  • The Directory property retrieves an object that represents the parent directory of a file.

  • The DirectoryName property retrieves the full path of the parent directory of a file.

  • The Exists property checks for the presence of a file before operating on it.

  • The IsReadOnly property retrieves or sets a value that specifies whether a file can be modified.

  • The Length retrieves the size of a file.

  • The Name retrieves the name of a file.

Constructors

File​Info(​String)

Initializes a new instance of the FileInfo class, which acts as a wrapper for a file path.

Properties

Directory

Gets an instance of the parent directory.

Directory​Name

Gets a string representing the directory's full path.

Exists

Gets a value indicating whether a file exists.

Is​Read​Only

Gets or sets a value that determines if the current file is read only.

Length

Gets the size, in bytes, of the current file.

Name

Gets the name of the file.

Methods

Append​Text()

Creates a StreamWriter that appends text to the file represented by this instance of the FileInfo.

Copy​To(​String)

Copies an existing file to a new file, disallowing the overwriting of an existing file.

Copy​To(​String, ​Boolean)

Copies an existing file to a new file, allowing the overwriting of an existing file.

Create()

Creates a file.

Create​Text()

Creates a StreamWriter that writes a new text file.

Decrypt()

Decrypts a file that was encrypted by the current account using the Encrypt() method.

Delete()

Permanently deletes a file.

Encrypt()

Encrypts a file so that only the account used to encrypt the file can decrypt it.

Get​Access​Control(​Access​Control​Sections)

Gets a FileSecurity object that encapsulates the specified type of access control list (ACL) entries for the file described by the current FileInfo object.

Get​Access​Control()

Gets a FileSecurity object that encapsulates the access control list (ACL) entries for the file described by the current FileInfo object.

Move​To(​String)

Moves a specified file to a new location, providing the option to specify a new file name.

Open(​File​Mode)

Opens a file in the specified mode.

Open(​File​Mode, ​File​Access)

Opens a file in the specified mode with read, write, or read/write access.

Open(​File​Mode, ​File​Access, ​File​Share)

Opens a file in the specified mode with read, write, or read/write access and the specified sharing option.

Open​Read()

Creates a read-only FileStream.

Open​Text()

Creates a StreamReader with UTF8 encoding that reads from an existing text file.

Open​Write()

Creates a write-only FileStream.

Replace(​String, ​String)

Replaces the contents of a specified file with the file described by the current FileInfo object, deleting the original file, and creating a backup of the replaced file.

Replace(​String, ​String, ​Boolean)

Replaces the contents of a specified file with the file described by the current FileInfo object, deleting the original file, and creating a backup of the replaced file. Also specifies whether to ignore merge errors.

Set​Access​Control(​File​Security)

Applies access control list (ACL) entries described by a FileSecurity object to the file described by the current FileInfo object.

To​String()

Returns the path as a string.

Extension Methods

GetAccessControl(FileInfo)
GetAccessControl(FileInfo, AccessControlSections)
SetAccessControl(FileInfo, FileSecurity)