Save all files in Visual Studio project as UTF-8

foreach (var f in new DirectoryInfo(@"...").GetFiles("*.cs", SearchOption.AllDirectories)) {
  string s = File.ReadAllText(f.FullName);
  File.WriteAllText (f.FullName, s, Encoding.UTF8);
}

import glob, codecs

for f in glob.glob("*.py"):
    data = open("f", "rb").read()
    if data.startswith(codecs.BOM_UTF8):
        # Already UTF-8
        continue
    # else assume ANSI code page
    data = data.decode("mbcs")
    data = codecs.BOM_UTF8 + data.encode("utf-8")
    open("f", "wb").write(data)

Function Write-Utf8([string] $path, [string] $filter='*.*')
{
    [IO.SearchOption] $option = [IO.SearchOption]::AllDirectories;
    [String[]] $files = [IO.Directory]::GetFiles($path, $filter, $option);
    foreach($file in $files)
    {
    	"Writing $file...";
    	[String]$s = [IO.File]::ReadAllText($file);
    	[IO.File]::WriteAllText($file, $s, [Text.Encoding]::UTF8);
    }
}

Dim s As String = ""
    Dim direc As DirectoryInfo = New DirectoryInfo("Your Directory path")

    For Each fi As FileInfo In direc.GetFiles("*.vb", SearchOption.AllDirectories)
        s = File.ReadAllText(fi.FullName, System.Text.Encoding.Default)
        File.WriteAllText(fi.FullName, s, System.Text.Encoding.Unicode)
    Next