Path.GetDirectoryName Method (System.IO)

GetDirectoryName Method

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

Path..::.GetDirectoryName Method

Updated: January 2010

Returns the directory information for the specified path string.

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

Syntax

Visual Basic (Declaration)

Public Shared Function GetDirectoryName ( _
    path As String _
) As String

Visual Basic (Usage)

Dim path As String
Dim returnValue As String

returnValue = Path.GetDirectoryName(path)

public static string GetDirectoryName(
    string path
)

Visual C++

public:
static String^ GetDirectoryName(
    String^ path
)

JScript

public static function GetDirectoryName(
    path : String
) : String

Parameters

path: Type: System..::.String
The path of a file or directory.

Return Value

Type: System..::.String
A String containing directory information for path, or nullNothingnullptra null reference (Nothing in Visual Basic) if path denotes a root directory or is nullNothingnullptra null reference (Nothing in Visual Basic). Returns String..::.Empty if path does not contain directory information.

Exceptions

Exception	Condition
ArgumentException	The path parameter contains invalid characters, is empty, or contains only white spaces.
PathTooLongException	The path parameter is longer than the system-defined maximum length.

Remarks

In most cases, the string returned by this method consists of all characters in the path up to but not including the last DirectorySeparatorChar or AltDirectorySeparatorChar. If the path consists of a root directory, such as "c:\", null is returned. Note that this method does not support paths using "file:". Because the returned path does not include the DirectorySeparatorChar or AltDirectorySeparatorChar, passing the returned path back into the GetDirectoryName method will result in the truncation of one folder level per subsequent call on the result string. For example, passing the path "C:\Directory\SubDirectory\test.txt" into the GetDirectoryName method will return "C:\Directory\SubDirectory". Passing that string, "C:\Directory\SubDirectory", into GetDirectoryName will result in "C:\Directory".

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

Examples

The following code example demonstrates using the GetDirectoryName method on a Windows-based desktop platform.

Visual Basic

Dim filepath As String = "C:\MyDir\MySubDir\myfile.ext"
Dim directoryName As String
Dim i As Integer = 0

While filepath <> Nothing
    directoryName = Path.GetDirectoryName(filepath)
    Console.WriteLine("GetDirectoryName('{0}') returns '{1}'", _
        filepath, directoryName)
    filepath = directoryName
    If i = 1
       filepath = directoryName + "\"  ' this will preserve the previous path
    End If
    i = i + 1
End While

'This code produces the following output:
'
' GetDirectoryName('C:\MyDir\MySubDir\myfile.ext') returns 'C:\MyDir\MySubDir'
' GetDirectoryName('C:\MyDir\MySubDir') returns 'C:\MyDir'
' GetDirectoryName('C:\MyDir\') returns 'C:\MyDir'
' GetDirectoryName('C:\MyDir') returns 'C:\'
' GetDirectoryName('C:\') returns ''

string filePath = @"C:\MyDir\MySubDir\myfile.ext";
string directoryName;
int i = 0;

while (filePath != null)
{
    directoryName = Path.GetDirectoryName(filePath);
    Console.WriteLine("GetDirectoryName('{0}') returns '{1}'",
        filePath, directoryName);
    filePath = directoryName;
    if (i == 1)
    {
        filePath = directoryName + @"\";  // this will preserve the previous path
    }
    i++;
}
/*
This code produces the following output:

GetDirectoryName('C:\MyDir\MySubDir\myfile.ext') returns 'C:\MyDir\MySubDir'
GetDirectoryName('C:\MyDir\MySubDir') returns 'C:\MyDir'
GetDirectoryName('C:\MyDir\') returns 'C:\MyDir'
GetDirectoryName('C:\MyDir') returns 'C:\'
GetDirectoryName('C:\') returns ''
*/

Visual C++

String^ filePath = "C:\\MyDir\\MySubDir\\myfile.ext";
String^ directoryName;
int i = 0;

while (filePath != nullptr)
{
    directoryName = Path::GetDirectoryName(filePath);
    Console::WriteLine("GetDirectoryName('{0}') returns '{1}'",
        filePath, directoryName);
    filePath = directoryName;
    if (i == 1)
    {
        filePath = directoryName + "\\";  // this will preserve the previous path
    }
    i++;
}
/*
This code produces the following output:

GetDirectoryName('C:\MyDir\MySubDir\myfile.ext') returns 'C:\MyDir\MySubDir'
GetDirectoryName('C:\MyDir\MySubDir') returns 'C:\MyDir'
GetDirectoryName('C:\MyDir\') returns 'C:\MyDir'
GetDirectoryName('C:\MyDir') returns 'C:\'
GetDirectoryName('C:\') returns ''
*/

JScript

var fileName : String = "C:\\mydir\\myfile.ext";
var path : String = "C:\\mydir\\";
var rootPath : String = "C:\\";
var directoryName : String;

directoryName = Path.GetDirectoryName(fileName);
Console.WriteLine("GetDirectoryName('{0}') returns '{1}'", 
                  fileName, directoryName);

directoryName = Path.GetDirectoryName(path);
Console.WriteLine("GetDirectoryName('{0}') returns '{1}'", 
                  path, directoryName);

directoryName = Path.GetDirectoryName(rootPath);
Console.WriteLine("GetDirectoryName('{0}') returns '{1}'", 
                  rootPath, directoryName);
/*
This code produces the following output:

GetDirectoryName('C:\mydir\myfile.ext') returns 'C:\mydir'
GetDirectoryName('C:\mydir\') returns 'C:\mydir'
GetDirectoryName('C:\') returns ''

*/

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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