Working directory in c sharp

private string? GetWorkingdir()
{
    string? tmpDir = "";
    try

    {
        string tmpDir1 = AppContext.BaseDirectory;
        if (Directory.Exists(tmpDir1))
        {
            Console.WriteLine("dir exists   read file ??");
            tmpDir = tmpDir1;
        }
    }
    catch (Exception ex)
    {
        System.Console.WriteLine(ex);
        tmpDir = null;
    }

    return tmpDir;
}