#PSTip: Using the System.Windows.Forms.FolderBrowserDialog Class

Note: This tip requires PowerShell 2.0 or above.

In PowerShell, it is possible to use GUI elements to allow for user input during scripts. Although it is possible to create your own forms from scratch, there are also many useful pre-built dialogs available. In this tip, we will see how the System.Windows.Forms.FolderBrowserDialog can be used to select a folder or path that can be used within a script.

On the first line we add the System.Forms class. This is to ensure the assembly is loaded. The New-Object Cmdlet creates the actual form and ShowDialog() Method on the object invokes the folder browser dialog.

Add-Type -AssemblyName System.Windows.Forms
$FolderBrowser = New-Object System.Windows.Forms.FolderBrowserDialog
[void]$FolderBrowser.ShowDialog()
$FolderBrowser.SelectedPath

It is also possible to specify in which folder the folder browser starts. By default this is the user’s desktop but this can be changed by modifying the SelectedPath property:

Add-Type -AssemblyName System.Windows.Forms
$FolderBrowser = New-Object System.Windows.Forms.FolderBrowserDialog -Property @{
    SelectedPath = 'C:\Temp’
}

[void]$FolderBrowser.ShowDialog()
$FolderBrowser.SelectedPath

To limit the folders the RootFolder property can be utilized, it should be noted that only special folders can be entered here, a folder of the [System.Environment+SpecialFolder] type. This means a custom path cannot be entered here. In the next code sample I have also disable the New Folder property, this is to ensure a user cannot create a folder and then select that folder:

Add-Type -AssemblyName System.Windows.Forms

$FolderBrowser = New-Object System.Windows.Forms.FolderBrowserDialog -Property @{
    RootFolder = 'MyDocuments'
    ShowNewFolderButton = $false
}

[void]$FolderBrowser.ShowDialog()
$FolderBrowser.SelectedPath

To get a full list of the available special folders the [enum] accelerator can be used to enumerate these folders. This code will generate list of the available values for the RootFolder property:

[Enum]::GetNames([System.Environment+SpecialFolder])

To learn more about this class or the values in the RootFolder property the following two MSDN articles can be used:

http://msdn.microsoft.com/en-us/library/system.windows.forms.folderbrowserdialog.aspx

http://msdn.microsoft.com/en-us/library/system.environment.specialfolder(v=vs.95).aspx