Question

I have a text file, where I have some points:

20,30
5,40
67,34
2,0
98,34

And how add this points to List? It’s my code what I made:

Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
dlg.DefaultExt = ".txt";
dlg.Filter = "Text document (.txt)|*.txt";

Nullable<bool> result = dlg.ShowDialog();

if (result == true)
{
    string filename = dlg.FileName;
    _mn.nazwa_pliku.Text = filename;

    int num = 0; //get a number of points/line in file

    for (int i = 0; i < num; i++) //for everyone line/point
    {

        int x = 0; //get X-value from file
        int y = 0; //get Y-value from file

        Klaster klaster = new Klaster();
        klaster.Punkty.Add(new Point(x, y));
        Klastry.Add(klaster);
    }       
}

Answer 1

One way is to use File.OpenText and read line-by-line:

// Open the stream and read it back. 
string s;
using (StreamReader sr = File.OpenText(filename)) 
{
    while ((s = sr.ReadLine()) != null) 
    {
        // parse the string and add the values to the list
        string[] parts = s.Split(new [] {','});
        if(parts.Length != 2)
        {
            // throw an exception
        }

        int x, y;

        if (!int.TryParse(parts[0],out x) ||
            !int.TryParse(parts[1],out y))
        {
            // throw an exception
        }

        Klaster klaster = new Klaster();
        klaster.Punkty.Add(new Point(x, y));
        Klastry.Add(klaster);
    }
}