【C#でファイルのパスをURIに変換する方法】が上手く機能しないケース

using System;

class Program

{

    static void Main(string[] args)

    {

        var uri = new Uri(@"C:\###\b c%20.txt");

        Console.WriteLine(uri.AbsoluteUri);

        var uri2 = new Uri(@"C:\あ\b c%20.txt");

        Console.WriteLine(uri2.AbsoluteUri);

    }

}

file:///C:/%23%23%23/b%20c%2520.txt

file:///C:/%E3%81%82/b%20c%2520.txt

file:///C:/%23%23%23/b%20c%2520.txt

file:///C:/%E3%81%82/b%20c%20.txt

var uri = new Uri(filename.Replace("%", "*"));

return new Uri(uri.AbsoluteUri.Replace("*", "%25"));