System.IO.File Class

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

See Also: File Members

Syntax

[System.Runtime.InteropServices.ComVisible(true)]
public static class File

Remarks

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

Many of the System.IO.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 System.IO.File members such as File.OpenText(string), File.CreateText(string), or File.Create(string).

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

The static methods of the System.IO.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 System.IO.FileInfo instead, because the security check will not always be necessary.

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 System.IO.File methods.

System.IO.FileAccess

Specifies read and write access to a file.

System.IO.FileShare

Specifies the level of access permitted for a file that is already in use.

System.IO.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:

For a list of common I/O tasks, see Common I/O Tasks.

Thread Safety

All public static members of this type are safe for multithreaded operations. No instance members are guaranteed to be thread safe.

Requirements

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0