.NET API > System > System.IO > File

File Class

Represents a static class that provides methods for creating, copying, deleting, moving, and opening files. This class cannot be inherited.

Summary

The System.IO.File class is a fundamental part of .NET's file system operations. It provides a set of static methods that allow developers to interact with files on the local file system without needing to create an instance of a file object. This makes common file operations concise and efficient.

Members

Methods

AppendAllLines

Appends lines to a file, and then closes the file. If the specified file does not exist, this method creates a file, writes the specified lines to the file, and then closes the file.

public static void AppendAllLines(string path, IEnumerable<string> contents); public static void AppendAllLines(string path, IEnumerable<string> contents, System.Text.Encoding encoding);

AppendAllText

Opens a text file, appends the specified string to the file, and then closes the file. If the file already exists, then its contents are appended. If the file does not exist, this method creates a file to hold the specified contents.

public static void AppendAllText(string path, string contents); public static void AppendAllText(string path, string contents, System.Text.Encoding encoding);

Copy

Copies an existing file to a new location.

public static void Copy(string sourceFileName, string destFileName); public static void Copy(string sourceFileName, string destFileName, bool overwrite);

Create

Creates or overwrites a file in the specified path and returns a new FileStream object that provides access to the file.

public static System.IO.FileStream Create(string path); public static System.IO.FileStream Create(string path, int bufferSize);

Delete

Deletes the specified file.

public static void Delete(string path);

Exists

Determines whether the specified file exists.

public static bool Exists(string path);

Move

Moves an existing file to a new location.

public static void Move(string sourceFileName, string destFileName);

ReadAllBytes

Opens a file, reads all bytes from the file, and then closes the file.

public static byte[] ReadAllBytes(string path);

ReadAllLines

Opens a text file, reads all lines of the file, and then closes the file.

public static string[] ReadAllLines(string path); public static string[] ReadAllLines(string path, System.Text.Encoding encoding);

ReadAllText

Opens a file, reads all lines of the file, and then closes the file.

public static string ReadAllText(string path); public static string ReadAllText(string path, System.Text.Encoding encoding);

WriteAllBytes

Creates a new file, writes the specified byte array to the file, and then closes the file. If the target file already exists, it is overwritten.

public static void WriteAllBytes(string path, byte[] bytes);

WriteAllLines

Creates a new file, writes a collection of strings to the file, and then closes the file. If the target file already exists, it is overwritten.

public static void WriteAllLines(string path, IEnumerable<string> contents); public static void WriteAllLines(string path, IEnumerable<string> contents, System.Text.Encoding encoding);

WriteAllText

Creates a new file, writes the specified string to the file, and then closes the file. If the target file already exists, it is overwritten.

public static void WriteAllText(string path, string contents); public static void WriteAllText(string path, string contents, System.Text.Encoding encoding);

Properties

The File class is static and does not have instance properties.

Events

The File class is static and does not raise events.

Remarks

All file path parameters for the File class are strings. These strings can represent relative or absolute paths. Relative paths are interpreted relative to the current working directory.

When performing operations that read from or write to files, ensure that the application has the necessary file system permissions. Otherwise, a System.UnauthorizedAccessException will be thrown.

See Also