Apply namespace to multiple C# files and associated aspx files using powershell

RecursivelyApplyNamespaces.ps1

param(
    [Parameter(Position=0,Mandatory=$true)]
    [Alias("Path")]
    $rootPath,
    [Parameter(Position=1,Mandatory=$true)]
    [Alias("Namespace")]
    $rootNamespace
)

$namespacePattern = "namespace\s+([^\s]+)"
$classPattern = "(public\s+)?partial\s+class\s+([^\s]+)"

$files = Get-ChildItem $rootPath -Recurse -Include *.cs
#$table = @()

foreach ($file in $files)
{
    $newNamespace = $file.FullName.Substring($rootPath.Length + 1)
    $newNamespace = $newNamespace.Substring(0, $newNamespace.IndexOf(".")).Replace("\", ".").Replace(" ", "").Replace("_", "")
    $newNamespace = [regex]::replace("${rootNamespace}.${newNamespace}", "\.([\w])(\w+)",{ ".$($args[0].Groups[1].Value.ToUpper())$($args[0].Groups[2].Value)" })
    $newNamespace = $newNamespace.Substring(0, $newNamespace.LastIndexOf("."))

    $newClassName = $file.Name.Substring(0, $file.Name.IndexOf("."))

    $content = Get-Content -Path $file | Out-String
    $match = $content | Select-String -Pattern $namespacePattern
    $currentNamespace = ""

    if ($null -ne $match.Matches)
    {
        $currentNamespace = $match.Matches[0].Groups[1]
        $content -replace $namespacePattern,"namespace $newNamespace" `
                 -replace $classPattern,"public partial class $newClassName" `
                 | Set-Content -Path "${file}" -Encoding UTF8
    }
    else
    {
        $content -replace $classPattern,"namespace ${newNamespace}`r`n{`r`npublic partial class $newClassName" `
                 -replace "\}\s*\Z","}`r`n}" `
                 | Set-Content -Path "${file}" -Encoding UTF8
    }

    $aspx = "$($file.DirectoryName)\$($file.Name.Substring(0, $file.Name.LastIndexOf(".")))"
    
    if (Test-Path -Path $aspx)
    {
        (Get-Content $aspx) -replace 'Inherits="([^"]+)"', ('Inherits="{0}.{1}"' -f $newNamespace,$newClassName) `
                            | Set-Content "${aspx}"
    }
}