How can one get an absolute or normalized file path in .NET?

I would write it like this:

public static string NormalizePath(string path)
{
    return Path.GetFullPath(new Uri(path).LocalPath)
               .TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)
               .ToUpperInvariant();
}

This should handle few scenarios like

1. uri and potential escaped characters in it, like

   file:///C:/Test%20Project.exe -> C:\TEST PROJECT.EXE

2. path segments specified by dots to denote current or parent directory

   c:\aaa\bbb\..\ccc -> C:\AAA\CCC

3. tilde shortened (long) paths

   C:\Progra~1\ -> C:\PROGRAM FILES

4. inconsistent directory delimiter character

   C:/Documents\abc.txt -> C:\DOCUMENTS\ABC.TXT

Other than those, it can ignore case, trailing \ directory delimiter character etc.

Path.GetFullPath perhaps?