FileInfo Class

Definition

Namespace:

System.IO

Assembly:

System.Runtime.dll

Source:

FileInfo.cs

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.

public ref class FileInfo sealed : System::IO::FileSystemInfo

public sealed class FileInfo : System.IO.FileSystemInfo

type FileInfo = class
    inherit FileSystemInfo

Public NotInheritable Class FileInfo
Inherits FileSystemInfo

Inheritance

Object

MarshalByRefObject

FileSystemInfo

FileInfo

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();
        var 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())
        {
            var s = "";
            while ((s = sr.ReadLine()) != null)
            {
                Console.WriteLine(s);
            }
        }

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

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

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

            // Delete the newly created file.
            fi2.Delete();
            Console.WriteLine($"{path2} was successfully deleted.");
        }
        catch (Exception e)
        {
            Console.WriteLine($"The process failed: {e.ToString()}");
        }
    }
}

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 New FileInfo(path1)

        ' Create a file to write to.
        Using sw As StreamWriter = fi.CreateText()
            sw.WriteLine("Hello")
            sw.WriteLine("And")
            sw.WriteLine("Welcome")
        End Using

        Try
            ' Open the file to read from.
            Using sr As StreamReader = fi.OpenText()
                Do While sr.Peek() >= 0
                    Console.WriteLine(sr.ReadLine())
                Loop
            End Using

            Dim fi2 As New FileInfo(path2)

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

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

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

        Catch e As Exception
            Console.WriteLine($"The process failed: {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

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

FileInfo(String)

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

Fields

FullPath	Represents the fully qualified path of the directory or file. (Inherited from FileSystemInfo)
OriginalPath	The path originally specified by the user, whether relative or absolute. (Inherited from FileSystemInfo)

Properties

Attributes	Gets or sets the attributes for the current file or directory. (Inherited from FileSystemInfo)
CreationTime	Gets or sets the creation time of the current file or directory. (Inherited from FileSystemInfo)
CreationTimeUtc	Gets or sets the creation time, in coordinated universal time (UTC), of the current file or directory. (Inherited from FileSystemInfo)
Directory	Gets an instance of the parent directory.
DirectoryName	Gets a string representing the directory's full path.
Exists	Gets a value indicating whether a file exists.
Extension	Gets the extension part of the file name, including the leading dot . even if it is the entire file name, or an empty string if no extension is present. (Inherited from FileSystemInfo)
FullName	Gets the full path of the directory or file. (Inherited from FileSystemInfo)
IsReadOnly	Gets or sets a value that determines if the current file is read only.
LastAccessTime	Gets or sets the time the current file or directory was last accessed. (Inherited from FileSystemInfo)
LastAccessTimeUtc	Gets or sets the time, in coordinated universal time (UTC), that the current file or directory was last accessed. (Inherited from FileSystemInfo)
LastWriteTime	Gets or sets the time when the current file or directory was last written to. (Inherited from FileSystemInfo)
LastWriteTimeUtc	Gets or sets the time, in coordinated universal time (UTC), when the current file or directory was last written to. (Inherited from FileSystemInfo)
Length	Gets the size, in bytes, of the current file.
LinkTarget	Gets the target path of the link located in FullName, or null if this FileSystemInfo instance doesn't represent a link. (Inherited from FileSystemInfo)
Name	Gets the name of the file.
UnixFileMode	Gets or sets the Unix file mode for the current file or directory. (Inherited from FileSystemInfo)

Methods

AppendText()	Creates a StreamWriter that appends text to the file represented by this instance of the FileInfo.
CopyTo(String)	Copies an existing file to a new file, disallowing the overwriting of an existing file.
CopyTo(String, Boolean)	Copies an existing file to a new file, allowing the overwriting of an existing file.
Create()	Creates a file.
CreateAsSymbolicLink(String)	Creates a symbolic link located in FullName that points to the specified pathToTarget. (Inherited from FileSystemInfo)
CreateObjRef(Type)	Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject)
CreateText()	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.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetLifetimeService()	Obsolete. Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject)
GetObjectData(SerializationInfo, StreamingContext)	Obsolete. Sets the SerializationInfo object with the file name and additional exception information. (Inherited from FileSystemInfo)
GetType()	Gets the Type of the current instance. (Inherited from Object)
InitializeLifetimeService()	Obsolete. Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
MemberwiseClone(Boolean)	Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject)
MoveTo(String)	Moves a specified file to a new location, providing the option to specify a new file name.
MoveTo(String, Boolean)	Moves a specified file to a new location, providing the options to specify a new file name and to overwrite the destination file if it already exists.
Open(FileMode)	Opens a file in the specified mode.
Open(FileMode, FileAccess)	Opens a file in the specified mode with read, write, or read/write access.
Open(FileMode, FileAccess, FileShare)	Opens a file in the specified mode with read, write, or read/write access and the specified sharing option.
Open(FileStreamOptions)	Initializes a new instance of the FileStream class with the specified creation mode, read/write and sharing permission, the access other FileStreams can have to the same file, the buffer size, additional file options and the allocation size.
OpenRead()	Creates a read-only FileStream.
OpenText()	Creates a StreamReader with UTF8 encoding that reads from an existing text file.
OpenWrite()	Creates a write-only FileStream.
Refresh()	Refreshes the state of the object. (Inherited from FileSystemInfo)
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.
ResolveLinkTarget(Boolean)	Gets the target of the specified link. (Inherited from FileSystemInfo)
ToString()	Returns the original path. Use the FullName or Name properties for the full path or file/directory name. (Inherited from FileSystemInfo)

Extension Methods

Create(FileInfo, FileMode, FileSystemRights, FileShare, Int32, FileOptions, FileSecurity)	Creates a new file stream, ensuring it is created with the specified properties and security settings.
GetAccessControl(FileInfo)	Returns the security information of a file.
GetAccessControl(FileInfo, AccessControlSections)	Returns the security information of a file.
SetAccessControl(FileInfo, FileSecurity)	Changes the security attributes of an existing file.

See also

• FileSystemWatcher
• DriveInfo
• File and Stream I/O
• How to: Read Text from a File
• How to: Write Text to a File
• How to: Read and Write to a Newly Created Data File