C#: Implementation of, or alternative to, StrCmpLogicalW in shlwapi.dll

Question

For natural sorting in my application I currently P/Invoke a function called StrCmpLogicalW in shlwapi.dll. I was thinking about trying to run my application under Mono, but

Answer 1

If you're running on Windows XP or newer, you can PInvoke to the shell function StrCmpLogicalW:

public static int StrCmpLogical(String s1, String s2)
{
    if (String.IsNullOrEmpty(s1) && !String.IsNullOrEmpty(s2))
        return 1; //empty s1 comes after s2
    else if (String.IsNullOrEmpty(s2) && !String.IsNullOrEmpty(s1))
        return -1; //non-empty string comes before empty

    return SafeNativeMethods.StrCmpLogicalW(s1, s2);
}

And then the internal unsafe class:

/// 

/// This class suppresses stack walks for unmanaged code permission. 
/// (System.Security.SuppressUnmanagedCodeSecurityAttribute is applied to this class.) 
/// This class is for methods that are safe for anyone to call. 
/// Callers of these methods are not required to perform a full security review to make sure that the 
/// usage is secure because the methods are harmless for any caller.
/// 
[SuppressUnmanagedCodeSecurity]
internal static class SafeNativeMethods
{
    [DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
    internal static extern Int32 StrCmpLogicalW(string psz1, string psz2);
}