FilePathHelper.cs

using System.Diagnostics;
 
namespace Vereinsmeisterschaften.Core.Helpers
{
    public static class FilePathHelper
    {
        public static string MakePathRelative(string fullPath, string rootFolder)
        {
            if(string.IsNullOrEmpty(fullPath))
            {
                return "."; // Return current directory if fullPath is empty
            }
            if(!IsPathFullyQualified(fullPath))
            {
                return fullPath;
            }
            // Remove any relative paths from these strings
            fullPath = Path.GetFullPath(fullPath);
            rootFolder = Path.GetFullPath(rootFolder);
            return Path.GetRelativePath(rootFolder, fullPath);
        }

        public static string MakePathAbsolute(string relativePath, string rootFolder)
        {
            if(IsPathFullyQualified(relativePath))
            {
                return relativePath; // already absolute
            }
            else
            {
                return Path.GetFullPath(Path.Combine(rootFolder, relativePath));
            }
        }

        public static bool IsPathFullyQualified(string path)
        {
            var root = Path.GetPathRoot(path);
            return root != null && (root.StartsWith(@"\\") || root.EndsWith(@"\") && root != @"\");
        }

        public static bool IsPathDirectory(string path)
        {
            if (path == null) throw new ArgumentNullException("path");
            path = path.Trim();
 
            if (Directory.Exists(path))
                return true;
 
            if (File.Exists(path))
                return false;
 
            // neither file nor directory exists. guess intention
 
            // if has trailing slash then it's a directory
            if (new[] { "\\", "/" }.Any(x => path.EndsWith(x)))
                return true; // ends with slash
 
            // if has extension then its a file; directory otherwise
            return string.IsNullOrWhiteSpace(Path.GetExtension(path));
        }

        public static void OpenWithDefaultProgram(string path)
        {
            using (Process fileopener = new Process())
            {
                fileopener.StartInfo.FileName = "explorer";
                fileopener.StartInfo.Arguments = "\"" + path + "\"";
                fileopener.Start();
            }
        }
    }
}