C# relative, absolute path

Question

Hello,

why is not workling?
I use relative path.

ToXMLFile($@"..\..\Data\Orders\{CurrentOrderSerials.OrderId}.xml");  

  public static void ToXMLFile<T>(this T obj, string filePath, bool omitDeclaration = true) where T : class  
        {  
            using (StreamWriter writer = new StreamWriter(filePath))  

C:_Prog\XXX\APP\Data\Orders

I expect two levels higher, not from bin folder.

Answer 1

You can use Path.GetFullPath with a relative path =>

string sCurrentDirectory = AppDomain.CurrentDomain.BaseDirectory;              
string sFile = System.IO.Path.Combine(sCurrentDirectory, @"..\..\..\Data\Orders\Test.xml");  
string sFilePath = Path.GetFullPath(sFile);  

Answer 2

Just think about it: two levels up could be multiple directories. So which one to choose?
You need to provide a fully qualified path.

This is how it is usually done. The System.IO.Path contains multiple useful methods to handle directory and file processing.

void Main()
{
 const string baseDir = @"e:\temp";

 string fileName = "mynewfile.xml";

 string fullyQualifiedFileName = Path.Combine(baseDir, fileName);
 Console.WriteLine("Fully qualified file name: '{0}'", fullyQualifiedFileName);
}

Answer 3

If you need the level then consider the following which given a level gets a parent folder according to the level provided so then combine that path with a file name, use File.Exists etc.

Helper class

using System;
using System.Collections.Generic;
using System.IO;

namespace Utilities.Classes 
{
    public static class DirectoryHelper
    {
        public static string UpperFolder(int level, string folderName = "")
        {
            if (string.IsNullOrWhiteSpace(folderName))
            {
                folderName = AppDomain.CurrentDomain.BaseDirectory;
            }

            var folderList = new List<string>();

            while (!string.IsNullOrWhiteSpace(folderName))
            {
                var parentFolder = Directory.GetParent(folderName);
                if (parentFolder == null)
                {
                    break;
                }

                folderName = Directory.GetParent(folderName).FullName;
                folderList.Add(folderName);
            }

            if (folderList.Count > 0 && level > 0)
            {
                return level - 1 <= folderList.Count - 1 ? folderList[level - 1] : folderName;
            }

            return folderName;
        }

        public static string CurrentSolutionFolder() => UpperFolder(4);
    }
}

Form code

Add this using statement

using static Utilities.Classes.DirectoryHelper;

Simple usage

Debug.WriteLine(CurrentSolutionFolder());
Debug.WriteLine("");
for (int index = 0; index < 5; index++)
{
    Debug.WriteLine($"{index}\t{UpperFolder(index)}");
}