.Net and File System

What are File System Classes?

                                    System.IO namespace contains classes to obtain information and manipulate file, directories and drives. Most of the classes inherit from FileSystemInfo, and they are named like FileInfo, DirectoryInfo.

DriveInfo class provides information about a drive but it doesn’t inherit from FileSystemInfo.

Utility classes expose static methods to perform certain operations on FileSystem. These classes include File, Directory, and Path.

FileSystemInfo Class:

Public Methods:

Name	Description
Delete	Deletes a file or directory.
Refresh	Refreshes the state of the object.

Public Properties:

Name	Description
Attributes	Gets or sets the FileAttributes of the current FileSystemInfo.
CreationTime	Gets or sets the creation time of the current FileSystemInfo object.
CreationTimeUtc	Gets or sets the creation time, in coordinated universal time (UTC), of the current FileSystemInfo object.
Exists	Gets a value indicating whether the file or directory exists.
Extension	Gets the string representing the extension part of the file.
FullName	Gets the full path of the directory or file.
LastAccessTime	Gets or sets the time the current file or directory was last accessed.
LastAccessTimeUtc	Gets or sets the time, in coordinated universal time (UTC), that the current file or directory was last accessed.
LastWriteTime	Gets or sets the time when the current file or directory was last written to.
LastWriteTimeUtc	Gets or sets the time, in coordinated universal time (UTC), when the current file or directory was last written to.
Name	For files, gets the name of the file. For directories, gets the name of the last directory in the hierarchy if a hierarchy exists. Otherwise, the Name property gets the name of the directory.

The FileInfo class:

                                The FileInfo class provides basic functionality to access and manipulate a single file in the file system.

FileInfo Properties:

Name	Description
Directory	Gets an instance of the parent directory.
DirectoryName	Gets a string representing the directory's full path.
IsReadOnly	Gets or sets a value that determines if the current file is read only.
Length	Gets the size, in bytes, of the current file.

FileInfo Methods:

Name	Description
AppendText	Creates a StreamWriter that appends text to the file represented by this instance of the FileInfo.
CopyTo	Overloaded. Copies an existing file to a new file.
Create	Creates a file.
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. (Overrides .Delete().)
Encrypt	Encrypts a file so that only the account used to encrypt the file can decrypt it.
GetAccessControl	Overloaded. Gets a FileSecurity object that encapsulates the access control list (ACL) entries for the file described by the current FileInfo object.
GetObjectData	Sets the SerializationInfo object with the file name and additional exception information. (Inherited from FileSystemInfo.)
MoveTo	Moves a specified file to a new location, providing the option to specify a new file name.
Open	Overloaded. Opens a file with various read/write and sharing privileges.
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	Overloaded. 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.
SetAccessControl	Applies access control list (ACL) entries described by a FileSecurity object to the file described by the current FileInfo object.
ToString	Returns the path as a string. (Overrides .ToString().)

Getting Information about a File:

FileInfo vBootIniInfo = new FileInfo(“C:\\boot.ini”);

If(vBootIniInfo.Exists)

{

                Console.WriteLine(vBootIniInfo.Name + “ : ”+ vBootIniInfo.FullName);

}

To Copy/Move a File use:

vBootIniInfo.CopyTo(“C:\\boot.bak”);

vBootIniInfo.MoveTo(“C:\\boot.bak”);

DirectoryInfo Class:

                                Provides basic functionality to access and manipulate a single directory.

DirectoryInfo Properties:

Parent:                 Parent directory

Root:                     Root directory

DirectoryInfo Methods:

Name	Description
Create	Overloaded. Creates a directory.
CreateObjRef	Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
CreateSubdirectory	Overloaded. Creates a subdirectory or subdirectories on the specified path. The specified path can be relative to this instance of the DirectoryInfo class.
Delete	Overloaded. Overridden. Deletes a DirectoryInfo and its contents from a path.
Equals	Overloaded. Determines whether two Object instances are equal. (Inherited from Object.)
GetAccessControl	Overloaded. Gets the access control list (ACL) entries for the current directory.
GetDirectories	Overloaded. Returns the subdirectories of the current directory.
GetFiles	Overloaded. Returns a file list from the current directory.
GetFileSystemInfos	Overloaded. Retrieves an array of strongly typed FileSystemInfo objects representing files and subdirectories of the current directory.
InitializeLifetimeService	Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
MoveTo	Moves a DirectoryInfo instance and its contents to a new path.
Refresh	Refreshes the state of the object. (Inherited from FileSystemInfo.)
SetAccessControl	Applies access control list (ACL) entries described by a DirectorySecurity object to the directory described by the current DirectoryInfo object.
ToString	Overridden. Returns the original path that was passed by the user.

Enumerating Files in a Directory:

DirectoryInfo dr = new DirectoryInfo (“C:\\windows”);

foreach(FileInfo file in dr.GetFiles())

{

                Console.WriteLine(“:\\” + file.Name);

}

DriveInfo class:

                                  One can query available drives and capacity related information.

DriveInfo Properties:

Name	Description
AvailableFreeSpace	Indicates the amount of available free space on a drive.
DriveFormat	Gets the name of the file system, such as NTFS or FAT32.
DriveType	Gets the drive type.
IsReady	Gets a value indicating whether a drive is ready.
Name	Gets the name of a drive.
RootDirectory	Gets the root directory of a drive.
TotalFreeSpace	Gets the total amount of free space available on a drive.
TotalSize	Gets the total size of storage space on a drive.
VolumeLabel	Gets or sets the volume label of a drive.

DriveInfo Methods:

GetDrives: A static method that returns all the available drives.

DriveType Enumeration:

Enum	Description
CDRom	The drive is an optical disc device, such as a CD or DVD-ROM.
Fixed	The drive is a fixed disk.
Network	The drive is a network drive.
NoRootDirectory	The drive does not have a root directory.
Ram	The drive is a RAM disk.
Removable	The drive is a removable storage device, such as a floppy disk drive or a USB flash drive.
Unknown	The type of drive is unknown.

Enumerating Drives:

DriveInfo[] dinfos = DriveInfo.GetDrives();

foreach(DriveInfo vinfo in dinfos)

                Console.WriteLine(vinfo.Name + “ : ” + vinfo.DriveType + “\n”);

Path Class:

                Helps in manipulating file system paths.

Name	Description
ChangeExtension	Changes the extension of a path string.
Combine	Combines two path strings.
GetDirectoryName	Returns the directory information for the specified path string.
GetExtension	Returns the extension of the specified path string.
GetFileName	Returns the file name and extension of the specified path string.
GetFileNameWithoutExtension	Returns the file name of the specified path string without the extension.
GetFullPath	Returns the absolute path for the specified path string.
GetInvalidFileNameChars	Gets an array containing the characters that are not allowed in file names.
GetInvalidPathChars	Gets an array containing the characters that are not allowed in path names.
GetPathRoot	Gets the root directory information of the specified path.
GetRandomFileName	Returns a random folder name or file name.
GetTempFileName	Creates a uniquely named, zero-byte temporary file on disk and returns the full path of that file.
GetTempPath	Returns the path of the current system's temporary folder.
HasExtension	Determines whether a path includes a file name extension.
IsPathRooted	Gets a value indicating whether the specified path string contains absolute or relative path information.

The FileSystemWatcher class:

WaitForChanged

Overloaded. A synchronous method that returns a structure that contains specific information on the change that occurred.

Properties:

Name	Description
Container	Gets the IContainer that contains the Component. (Inherited from Component.)
EnableRaisingEvents	Gets or sets a value indicating whether the component is enabled.
Filter	Gets or sets the filter string used to determine what files are monitored in a directory.
IncludeSubdirectories	Gets or sets a value indicating whether subdirectories within the specified path should be monitored.
InternalBufferSize	Gets or sets the size of the internal buffer.
NotifyFilter	Gets or sets the type of changes to watch for.
Path	Gets or sets the path of the directory to watch.
Site	Gets or sets an ISite for the FileSystemWatcher. (Overrides .Site.)
SynchronizingObject	Gets or sets the object used to marshal the event handler calls issued as a result of a directory change.

Events:

Name	Description
Changed	Occurs when a file or directory in the specified Path is changed.
Created	Occurs when a file or directory in the specified Path is created.
Deleted	Occurs when a file or directory in the specified Path is deleted.
Renamed	Occurs when a file or directory in the specified Path is renamed.