How to convert a relative path to an absolute path in a Windows application?

Question

How do I convert a relative path to an absolute path in a Windows application?

I know we can use server.MapPath() in ASP.NET. But what can we do in a Windows applica

Answer 1

It's a bit older topic, but it might be useful for someone. I have solved a similar problem, but in my case, the path was not at the beginning of the text.

So here is my solution:

public static class StringExtension
{
    private const string parentSymbol = "..\\";
    private const string absoluteSymbol = ".\\";
    public static String AbsolutePath(this string relativePath)
    {
        string replacePath = AppDomain.CurrentDomain.BaseDirectory;
        int parentStart = relativePath.IndexOf(parentSymbol);
        int absoluteStart = relativePath.IndexOf(absoluteSymbol);
        if (parentStart >= 0)
        {
            int parentLength = 0;
            while (relativePath.Substring(parentStart + parentLength).Contains(parentSymbol))
            {
                replacePath = new DirectoryInfo(replacePath).Parent.FullName;
                parentLength = parentLength + parentSymbol.Length;
            };
            relativePath = relativePath.Replace(relativePath.Substring(parentStart, parentLength), string.Format("{0}\\", replacePath));
        }
        else if (absoluteStart >= 0)
        {
            relativePath = relativePath.Replace(".\\", replacePath);
        }
        return relativePath;
    }
}

Example:

Data Source=.\Data\Data.sdf;Persist Security Info=False;
Data Source=..\..\bin\Debug\Data\Data.sdf;Persist Security Info=False;

Answer 2

This one works for paths on different drives, for drive-relative paths and for actual relative paths. Heck, it even works if the basePath isn't actually absolute; it always uses the current working directory as final fallback.

public static String GetAbsolutePath(String path)
{
    return GetAbsolutePath(null, path);
}

public static String GetAbsolutePath(String basePath, String path)
{
    if (path == null)
        return null;
    if (basePath == null)
        basePath = Path.GetFullPath("."); // quick way of getting current working directory
    else
        basePath = GetAbsolutePath(null, basePath); // to be REALLY sure ;)
    String finalPath;
    // specific for windows paths starting on \ - they need the drive added to them.
    // I constructed this piece like this for possible Mono support.
    if (!Path.IsPathRooted(path) || "\\".Equals(Path.GetPathRoot(path)))
    {
        if (path.StartsWith(Path.DirectorySeparatorChar.ToString()))
            finalPath = Path.Combine(Path.GetPathRoot(basePath), path.TrimStart(Path.DirectorySeparatorChar));
        else
            finalPath = Path.Combine(basePath, path);
    }
    else
        finalPath = path;
    // resolves any internal "..\" to get the true full path.
    return Path.GetFullPath(finalPath);
}

Answer 3

Have you tried:

string absolute = Path.GetFullPath(relative);

? Note that that will use the current working directory of the process, not the directory containing the executable. If that doesn't help, please clarify your question.

Answer 4

If you want to get the path relative to your .exe then use

string absolute = Path.Combine(Application.ExecutablePath, relative);