R – Custom WinForms DataGridView issues with adding columns

Is the property on the grid you are binding to Opcode as well?.. if you want to bind directly to List you would just DataSource = list. The databindings allows custom binding. are you trying to do something other than the datasource?

You are getting a bunch of empty rows? do the auto generated columns have names? Have you verified data is in the object (not just string.empty) ?

    class MyObject
    {
        public string Something { get; set; }
        public string Text { get; set; }
        public string Other { get; set; }
    }

    public Form1()
    {
        InitializeComponent();

        List<MyObject> myList = new List<MyObject>();

        for (int i = 0; i < 200; i++)
        {
            string num = i.ToString();
            myList.Add(new MyObject { Something = "Something " + num , Text = "Some Row " + num , Other = "Other " + num  });
        }

        dataGridView1.DataSource = myList;
    }

this should work fine...

This trick works for me:

    grd.DataSource = DT;

    // Set your desired AutoSize Mode:
    grd.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
    grd.Columns[1].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
    grd.Columns[2].AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;

    // Now that DataGridView has calculated it's Widths; we can now store each column Width values.
    for (int i = 0; i <= grd.Columns.Count - 1; i++)
    {
        // Store Auto Sized Widths:
        int colw = grd.Columns[i].Width;

        // Remove AutoSizing:
        grd.Columns[i].AutoSizeMode = DataGridViewAutoSizeColumnMode.None;

        // Set Width to calculated AutoSize value:
        grd.Columns[i].Width = colw;
    }

In the Code above: You set the Columns AutoSize Property to whathever AutoSizeMode you need. Then (Column by Column) you store each column Width value (from AutoSize value); Disable the AutoSize Property and finally, set the Column Width to the Width value you previously stored.