Remove duplicate from two generic list C#

Question

I've got a problem. I need to write a csv file (whit append) but i can't write the item that are duplicate in the file. So:

I read all item in the csv file, I add the item to my list (that then I write to the file), and I want to remove duplicate from the list before writing in the file... I try to use "distinct" but it doesn't work.

My class:

class MyList_Base
{
  public string Cliente  {get; set; }
  public double   TotaleProvvigione  { get; set; }
  public double   TotalePunti        { get; set; }
  public string   Descrizione        { get; set; }
  public double   Pezzi              { get; set; }
  public double   Provvigione        { get; set; } 
  public bool     DigitalPen         { get; set; }
  public bool     ReferenzaPersonale { get; set; }
  public DateTime Data               { get; set; }
  public string   Mese               { get; set; }
  public string   Gara               { get; set; }
  public double   PuntiGara          { get; set; }
  public string   Note               { get; set; }


  public MyList_Base(string cliente, double totaleProvvigione, double totalePunti, string descrizione, double pezzi, double provvigione, bool digitalPen, bool referenzaPersonale, DateTime data, string mese, string gara, double puntiGara, string note)
  {
    Cliente            = cliente;
    TotaleProvvigione  = totaleProvvigione;
    TotalePunti        = totalePunti;
    Descrizione        = descrizione;
    Pezzi              = pezzi;
    Provvigione        = provvigione;
    DigitalPen         = digitalPen;
    ReferenzaPersonale = referenzaPersonale;
    Data               = data;
    Mese               = mese;
    Gara               = gara;
    PuntiGara          = puntiGara;
    Note               = Note;
  }

  public override string ToString()
  {
    return Cliente + ";" + TotaleProvvigione + ";" + TotalePunti + ";" + Descrizione + ";" + Pezzi + ";" + Provvigione + ";" + DigitalPen + ";" + ReferenzaPersonale + ";" + Data + ";" + Mese + ";" + Gara + ";" + PuntiGara+";" + Note;
  }

  public static MyList_Base Parse(string csv)
  {
    string[] tmp = csv.Split(';');
    return new MyList_Base(tmp[0], Convert.ToDouble(tmp[1]), Convert.ToDouble(tmp[2]), tmp[3], Convert.ToDouble(tmp[4]), Convert.ToDouble(tmp[5]), Convert.ToBoolean(tmp[6]), Convert.ToBoolean(tmp[7]), Convert.ToDateTime(tmp[8]), tmp[9], tmp[10], Convert.ToDouble(tmp[11]), tmp[11]);
  }

}

And this is what I need to do : "//TODO: REMOVE DUPLICATE"

public List<MyList_Base> LoadMyData(string nomeFile)
{
  if (!File.Exists(nomeFile)) return null;

  List<MyList_Base> tmp = new List<MyList_Base>();
  StreamReader sr = new StreamReader(nomeFile);

  while(!sr.EndOfStream)
  {
    tmp.Add(MyList_Base.Parse(sr.ReadLine()));
  }

  sr.Close();
  return tmp;
}

public bool Save(string nomeFile)
{
  var tmp = LoadMyData(nomeFile);
  StreamWriter sw = new StreamWriter(nomeFile);

  //TODO: REMOVE DUPLICATE 
  foreach (var x in this)
  {
     sw.WriteLine(x.ToString());
  }

  sw.Close();
  return true;
}

Can someone help me?

PS: sorry for my bad english.. Fabio.

what do you consider a duplicate? Does all values have to be the same or just key attributes? — Rune FS, May 10 '15 at 08:37
i consider duplicate one item of the list whit the all same value of the another item.. i don't have a primary key, i need to don't have two same items in the list — Fabio, May 10 '15 at 08:40

molnargab · Accepted Answer · 2015-05-10T09:00:43.053

3

Enumerable.Distinct extension method may help you.

There is an overload with an IEqualityComparer if you can't use the default (Equals method of MyList_Base). This may be the case if e.g. your Equals method would only compare some of the fields, but you would want to check all them.

edited May 10 '15 at 09:00

answered May 10 '15 at 08:51

molnargab

162
7

To be THE answer IMO you should also explain **why** he needs a IComparer... – Adriano Repetti May 10 '15 at 08:53
Thanks, expanded the answer a bit. – molnargab May 10 '15 at 09:02

score 0 · Answer 2 · answered May 10 '15 at 09:15

0

You can use Distinct extension method of the list and pass an object which implements IEqualityComparer. Check this:

http://blog.alex-turok.com/2013/03/c-linq-and-iequalitycomparer.html

answered May 10 '15 at 09:15

Randeep Singh

1,275
14
29

Remove duplicate from two generic list C#

2 Answers2