Changes the extension of a path string.
Public Shared Function ChangeExtension ( _ path As String, _ extension As String _ ) As String
Dim path As String Dim extension As String Dim returnValue As String returnValue = Path.ChangeExtension(path, _ extension)
public static string ChangeExtension( string path, string extension )
public: static String^ ChangeExtension( String^ path, String^ extension )
public static function ChangeExtension( path : String, extension : String ) : String
path contains one or more of the invalid characters defined in GetInvalidPathChars.
If neither path nor extension contains a period (.), ChangeExtension adds the period.
The extension parameter can contain multiple periods and any valid path characters, and can be any length. If extension is nullNothingnullptra null reference (Nothing in Visual Basic), the returned string contains the contents of path with the last period and all characters following it removed.
If extension is an empty string, the returned path string contains the contents of path with any characters following the last period removed.
If path does not have an extension and extension is not nullNothingnullptra null reference (Nothing in Visual Basic), the returned string contains path followed by extension.
If extension is not nullNothingnullptra null reference (Nothing in Visual Basic) and does not contain a leading period, the period is added.
If path contains a multiple extension separated by multiple periods, the returned string contains the contents of path with the last period and all characters following it replaced by extension. For example, if path is "\Dir1\examples\pathtests.csx.txt" and extension is "cs", the modified path is "\Dir1\examples\pathtests.csx.cs".
It is not possible to verify that the returned results are valid in all scenarios. For example, if path is empty, extension is appended.
For a list of common I/O tasks, see Common I/O Tasks.
The following code example demonstrates a use of the ChangeExtension method.
Imports System Imports System.IO Public Class PathSnippets Public Sub ChangeExtension() Dim goodFileName As String = "C:\mydir\myfile.com.extension" Dim badFileName As String = "C:\mydir\" Dim result As String result = Path.ChangeExtension(goodFileName, ".old") Console.WriteLine("ChangeExtension({0}, '.old') returns '{1}'", goodFileName, result) result = Path.ChangeExtension(goodFileName, "") Console.WriteLine("ChangeExtension({0}, '') returns '{1}'", goodFileName, result) result = Path.ChangeExtension(badFileName, ".old") Console.WriteLine("ChangeExtension({0}, '.old') returns '{1}'", badFileName, result) ' This code produces output similar to the following: ' ' ChangeExtension(C:\mydir\myfile.com.extension, '.old') returns 'C:\mydir\myfile.com.old' ' ChangeExtension(C:\mydir\myfile.com.extension, '') returns 'C:\mydir\myfile.com.' ' ChangeExtension(C:\mydir\, '.old') returns 'C:\mydir\.old'
using System; using System.IO; public class PathSnippets { public void ChangeExtension() { string goodFileName = @"C:\mydir\myfile.com.extension"; string badFileName = @"C:\mydir\"; string result; result = Path.ChangeExtension(goodFileName, ".old"); Console.WriteLine("ChangeExtension({0}, '.old') returns '{1}'", goodFileName, result); result = Path.ChangeExtension(goodFileName, ""); Console.WriteLine("ChangeExtension({0}, '') returns '{1}'", goodFileName, result); result = Path.ChangeExtension(badFileName, ".old"); Console.WriteLine("ChangeExtension({0}, '.old') returns '{1}'", badFileName, result); // This code produces output similar to the following: // // ChangeExtension(C:\mydir\myfile.com.extension, '.old') returns 'C:\mydir\myfile.com.old' // ChangeExtension(C:\mydir\myfile.com.extension, '') returns 'C:\mydir\myfile.com.' // ChangeExtension(C:\mydir\, '.old') returns 'C:\mydir\.old'
#using <system.dll> using namespace System; using namespace System::IO; void ChangeExtension() { String^ goodFileName = "C:\\mydir\\myfile.com.extension"; String^ badFileName = "C:\\mydir\\"; String^ result; result = Path::ChangeExtension( goodFileName, ".old" ); Console::WriteLine( "ChangeExtension({0}, '.old') returns '{1}'", goodFileName, result ); result = Path::ChangeExtension( goodFileName, "" ); Console::WriteLine( "ChangeExtension({0}, '') returns '{1}'", goodFileName, result ); result = Path::ChangeExtension( badFileName, ".old" ); Console::WriteLine( "ChangeExtension({0}, '.old') returns '{1}'", badFileName, result ); // This code produces output similar to the following: // // ChangeExtension(C:\mydir\myfile.com.extension, '.old') returns 'C:\mydir\myfile.com.old' // ChangeExtension(C:\mydir\myfile.com.extension, '') returns 'C:\mydir\myfile.com.' // ChangeExtension(C:\mydir\, '.old') returns 'C:\mydir\.old'
var goodFileName : String = "C:\\mydir\\myfile.com.extension"; var badFileName : String = "C:\\mydir\\"; var result : String; result = Path.ChangeExtension(goodFileName, ".old"); Console.WriteLine("ChangeExtension({0}, '.old') returns '{1}'", goodFileName, result); result = Path.ChangeExtension(goodFileName, ""); Console.WriteLine("ChangeExtension({0}, '') returns '{1}'", goodFileName, result); result = Path.ChangeExtension(badFileName, ".old"); Console.WriteLine("ChangeExtension({0}, '.old') returns '{1}'", badFileName, result);
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
# change-extensions.ps1# changes extensions using PowerShell# Thomas Lee - tfl@psp.co.uk# setup file names$goodFileName = "C:\mydir\myfile.com.extension"$badFileName = "C:\mydir\"# change file name$result = [System.IO.Path]::ChangeExtension($goodFileName, ".old")"ChangeExtension({0},'.old') returns '{1}'" -f $goodFileName, $result$result = [System.IO.Path]::ChangeExtension($goodFileName, "")"ChangeExtension({0}, '') returns '{1}'" -f $goodFileName, $result$result = [System.IO.Path]::ChangeExtension($badFileName, ".old")"ChangeExtension({0}, '.old') returns '{1}'" -f $badFileName, $result
PS C:\Users\tfl> .\change-extensions.ps1ChangeExtension(C:\mydir\myfile.com.extension,'.old') returns 'C:\mydir\myfile.com.old'ChangeExtension(C:\mydir\myfile.com.extension, '') returns 'C:\mydir\myfile.com.'ChangeExtension(C:\mydir\, '.old') returns 'C:\mydir\.old'