Show-FileBrowser

function Show-FolderBrowser
{
    Param ( [Parameter(Mandatory=0,ValueFromPipeline=1)][string]$Title='Browse For Folder',
            [Parameter(Mandatory=0,ValueFromPipeline=1)][string]$SelectedPath = $(Split-Path $psISE.CurrentFile.FullPath),
            [Parameter(Mandatory=0,ValueFromPipeline=1)][switch]$ShowNewFolderButton)

    $FolderBrowser = New-Object System.Windows.Forms.FolderBrowserDialog;
    $FolderBrowser.Description = $Title
    $FolderBrowser.ShowNewFolderButton = $ShowNewFolderButton
    $FolderBrowser.SelectedPath = $SelectedPath
    $sp = $null

    $caller = [System.Windows.Forms.NativeWindow]::new()
    $caller.AssignHandle([System.Diagnostics.Process]::GetCurrentProcess().MainWindowHandle)

    if (($FolderBrowser.ShowDialog($caller)) -eq [System.Windows.Forms.DialogResult]::OK.value__)
    {
        $sp = $FolderBrowser.SelectedPath
    }

    #Cleanup
    $FolderBrowser.Dispose()

    return $sp
}

function Show-FileBrowser
{
    Param ( [Parameter(Mandatory=0,ValueFromPipeline=1)][string]$Title='Browse For File',
            [Parameter(Mandatory=0,ValueFromPipeline=1)][string]$InitialDirectory = $(Split-Path $psISE.CurrentFile.FullPath),
            [Parameter(Mandatory=0,ValueFromPipeline=1)][string]$Filter = 'All files (*.*)|*.*'
    )

    $FileBrowser = New-Object System.Windows.Forms.OpenFileDialog
    $FileBrowser.Title = $Title
    $FileBrowser.InitialDirectory = $InitialDirectory
    $FileBrowser.Filter = $Filter
    $fn = $null

    $caller = [System.Windows.Forms.NativeWindow]::new()
    $caller.AssignHandle([System.Diagnostics.Process]::GetCurrentProcess().MainWindowHandle)

    if (($FileBrowser.ShowDialog($caller)) -eq [System.Windows.Forms.DialogResult]::OK.value__)
    {
        $fn = $FileBrowser.FileName
    }

    #Cleanup
    $FileBrowser.Dispose()

    return $fn
}

function Show-SaveFileBrowser
{
    Param ( [Parameter(Mandatory=0,ValueFromPipeline=1)][string]$Title='Save File',
            [Parameter(Mandatory=0,ValueFromPipeline=1)][string]$InitialDirectory = $(Split-Path $psISE.CurrentFile.FullPath),
            [Parameter(Mandatory=0,ValueFromPipeline=1)][string]$Filter = 'All files (*.*)|*.*'
    )

    $SaveBrowser = New-Object System.Windows.Forms.SaveFileDialog
    $SaveBrowser.Title = $Title
    $SaveBrowser.InitialDirectory = $InitialDirectory
    $SaveBrowser.Filter = $Filter
    $fn = $null

    $caller = [System.Windows.Forms.NativeWindow]::new()
    $caller.AssignHandle([System.Diagnostics.Process]::GetCurrentProcess().MainWindowHandle)

    if (($SaveBrowser.ShowDialog($caller)) -eq [System.Windows.Forms.DialogResult]::OK.value__)
    {
        $fn = $SaveBrowser.FileName
    }

    #Cleanup
    $SaveBrowser.Dispose()

    return $fn
}

$documents = [Environment]::GetFolderPath("MyDocuments")

Clear-Host

Show-FolderBrowser -SelectedPath $documents -ShowNewFolderButton
Show-FileBrowser  -InitialDirectory $documents -Filter 'PowerShell files (*.ps1)|*.ps1'
Show-SaveFileBrowser -InitialDirectory $documents -Filter 'PowerShell files (*.ps1)|*.ps1'