Path Class


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Performs operations on String instances that contain file or directory path information. These operations are performed in a cross-platform manner.

To browse the .NET Framework source code for this type, see the Reference Source.

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

public static class Path

System_CAPS_pubmethodSystem_CAPS_staticChangeExtension(String, String)

Changes the extension of a path string.

System_CAPS_pubmethodSystem_CAPS_staticCombine(String, String)

Combines two strings into a path.

System_CAPS_pubmethodSystem_CAPS_staticCombine(String, String, String)

Combines three strings into a path.

System_CAPS_pubmethodSystem_CAPS_staticCombine(String, String, String, String)

Combines four strings into a path.


Combines an array of strings into a path.


Returns the directory information for the specified path string.


Returns the extension of the specified path string.


Returns the file name and extension of the specified path string.


Returns the file name of the specified path string without the extension.


Returns the absolute path for the specified path string.


Gets an array containing the characters that are not allowed in file names.


Gets an array containing the characters that are not allowed in path names.


Gets the root directory information of the specified path.


Returns a random folder name or file name.


Creates a uniquely named, zero-byte temporary file on disk and returns the full path of that file.


Returns the path of the current user's temporary folder.


Determines whether a path includes a file name extension.


Gets a value indicating whether the specified path string contains a root.


Provides a platform-specific alternate character used to separate directory levels in a path string that reflects a hierarchical file system organization.


Provides a platform-specific character used to separate directory levels in a path string that reflects a hierarchical file system organization.


Obsolete. Provides a platform-specific array of characters that cannot be specified in path string arguments passed to members of the Path class.


A platform-specific separator character used to separate path strings in environment variables.


Provides a platform-specific volume separator character.


To view the .NET Framework source code for this type, see the Reference Source. You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions.

The .NET Framework does not support direct access to physical disks through paths that are device names, such as "\\.\PHYSICALDRIVE0 ".

A path is a string that provides the location of a file or directory. A path does not necessarily point to a location on disk; for example, a path might map to a location in memory or on a device. The exact format of a path is determined by the current platform. For example, on some systems, a path can start with a drive or volume letter, while this element is not present in other systems. On some systems, file paths can contain extensions, which indicate the type of information stored in the file. The format of a file name extension is platform-dependent; for example, some systems limit extensions to three characters, and others do not. The current platform also determines the set of characters used to separate the elements of a path, and the set of characters that cannot be used when specifying paths. Because of these differences, the fields of the Path class as well as the exact behavior of some members of the Path class are platform-dependent.

A path can contain absolute or relative location information. Absolute paths fully specify a location: the file or directory can be uniquely identified regardless of the current location. Relative paths specify a partial location: the current location is used as the starting point when locating a file specified with a relative path. To determine the current directory, call Directory.GetCurrentDirectory.

Most members of the Path class do not interact with the file system and do not verify the existence of the file specified by a path string. Path class members that modify a path string, such as ChangeExtension, have no effect on names of files in the file system. Path members do, however, validate the contents of a specified path string, and throw an ArgumentException exception if the string contains characters that are not valid in path strings, as defined in the characters returned from the GetInvalidPathChars method. For example, on Windows-based desktop platforms, invalid path characters might include quote ("), less than (<), greater than (>), pipe (|), backspace (\b), null (\0), and Unicode characters 16 through 18 and 20 through 25.

The members of the Path class enable you to quickly and easily perform common operations such as determining whether a file name extension is part of a path, and combining two strings into one path name.

All members of the Path class are static and can therefore be called without having an instance of a path.


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.

Because all these operations are performed on strings, it is impossible to verify that the results are valid in all scenarios. For example, the GetExtension method parses a string that you pass to it and returns the extension from that string. However, this does not mean that a file with that extension exists on the disk.

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

The following code example demonstrates some of the main members of the Path class.

using System;
using System.IO;

class Test 

    public static void Main() 
        string path1 = @"c:\temp\MyTest.txt";
        string path2 = @"c:\temp\MyTest";
        string path3 = @"temp";

        if (Path.HasExtension(path1)) 
            Console.WriteLine("{0} has an extension.", path1);

        if (!Path.HasExtension(path2)) 
            Console.WriteLine("{0} has no extension.", path2);

        if (!Path.IsPathRooted(path3)) 
            Console.WriteLine("The string {0} contains no root information.", path3);

        Console.WriteLine("The full path of {0} is {1}.", path3, Path.GetFullPath(path3));
        Console.WriteLine("{0} is the location for temporary files.", Path.GetTempPath());
        Console.WriteLine("{0} is a file available for use.", Path.GetTempFileName());

        /* This code produces output similar to the following:
         * c:\temp\MyTest.txt has an extension.
         * c:\temp\MyTest has no extension.
         * The string temp contains no root information.
         * The full path of temp is D:\Documents and Settings\cliffc\My Documents\Visual Studio 2005\Projects\ConsoleApplication2\ConsoleApplication2\bin\Debug\temp.
         * D:\Documents and Settings\cliffc\Local Settings\Temp\8\ is the location for temporary files.
         * D:\Documents and Settings\cliffc\Local Settings\Temp\8\tmp3D.tmp is a file available for use.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1

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

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