File Class

[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]

Provides static methods for the creation, copying, deletion, moving, and opening of files, and aids in the creation of FileStream objects.

Inheritance Hierarchy

System. . :: . .Object
  System.IO..::..File

Namespace:  System.IO
Assembly:  System.IO (in System.IO.dll)

Syntax

'Declaration
Public NotInheritable Class File

public static class File

public ref class File abstract sealed

[<AbstractClass>]
[<Sealed>]
type File =  class end

public final class File

The File type exposes the following members.

Methods

	Name	Description
	Copy(String, String)	Copies an existing file to a new file. Overwriting a file of the same name is not allowed.
	Copy(String, String, Boolean)	Copies an existing file to a new file. Overwriting a file of the same name is allowed.
	Create(String)	Creates or overwrites a file in the specified path.
	Create(String, Int32)	Creates or overwrites the specified file.
	Delete	Deletes the specified file.
	Exists	Determines whether the specified file exists.
	GetAttributes	Gets the FileAttributes of the file on the path.
	Move	Moves a specified file to a new location, providing the option to specify a new file name.
	Open(String, FileMode)	Opens a FileStream on the specified path with read/write access.
	Open(String, FileMode, FileAccess)	Opens a FileStream on the specified path, with the specified mode and access.
	Open(String, FileMode, FileAccess, FileShare)	Opens a FileStream on the specified path, having the specified mode with read, write, or read/write access and the specified sharing option.
	OpenRead	Opens an existing file for reading.
	OpenWrite	Opens an existing file or creates a new file for writing.
	ReadAllBytes	Opens a binary file, reads the contents of the file into a byte array, and then closes the file.
	SetAttributes	Sets the specified FileAttributes of the file on the specified path.
	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.

Top

Remarks

Use the File class for typical operations such as copying, moving, renaming, creating, opening, deleting, and appending to files. You can also use the File class to get and set file attributes or DateTime information related to the creation, access, and writing of a file.

Many of the File 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 File members such as OpenText, CreateText, or Create.

Because all File methods are static, it might be more efficient to use a File method rather than a corresponding FileInfo instance method if you want to perform only one action. All File methods require the path to the file that you are manipulating.

The static methods of the File class perform security checks on all methods. If you are going to reuse an object several times, consider using the corresponding instance method of FileInfo instead, because the security check will not always be necessary.

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.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

System.IO Namespace