WinForms DataGridView no scrolling but start another column

Question

Here above is my DataGridView in WindForms. But I do not want it to scroll. What I want is when the rows fit the panel from top to bottom, new rows will be created in the right from the top. The expected version should work like the figure below.

And also, when I change the size of the window, the data rows should automatically rearrange themselves to fit the panel. I have no idea how to do it, and get no clue after searching all the questions related to DataGridView. Please kindly supply your thoughts or comments. Many thanks!

Answer 1

Here is a rough example using a DataTable that has a dynamically number of added columns:

public class StockInfo {
    public String Symbol;
    public decimal Price;
    public decimal Change;
}

public class StockForm : Form {

    SprawlingDGV dgv = new SprawlingDGV();

    public StockForm() {
        Controls.Add(dgv);
    }

}

public class SprawlingDGV : DataGridView {

    DataTable table = new DataTable();
    int previousNumRowsAvailable = -1;
    public List<StockInfo> StockData = new List<StockInfo>();

    public SprawlingDGV() {
        Dock = DockStyle.Fill;
        DataSource = table;
        AllowUserToAddRows = false;

        for (int i = 0; i < 50; i++) {
            StockInfo s = new StockInfo();
            s.Symbol = "Symbol" + i;
            s.Price = i;
            StockData.Add(s);
        }
    }

    protected override void OnCellFormatting(DataGridViewCellFormattingEventArgs e) {
        base.OnCellFormatting(e);
        // TBD: Hide the grid lines for unused cells
        if (e.Value == DBNull.Value)
            e.CellStyle.BackColor = Color.DarkGray;
    }

    protected override void OnResize(EventArgs e) {
        base.OnResize(e);

        DataTable table2 = new DataTable();
        var col1 = table2.Columns.Add("Symbol_0", typeof(String));
        var col2 = table2.Columns.Add("Price_0", typeof(decimal));
        var col3 = table2.Columns.Add("Change_0", typeof(decimal));
        int heightPerRow = 30; // TBD: determine height based on Font
        int numRowsAvailable = (this.Height - this.ColumnHeadersHeight) / heightPerRow;
        if (numRowsAvailable == previousNumRowsAvailable)
            return;
        previousNumRowsAvailable = numRowsAvailable;
        int n = Math.Max(1, numRowsAvailable);
        int id = 0;
        for (int i = 0, k = 0; i < StockData.Count; i++) {
            StockInfo s = StockData[i];
            DataRow row = null;
            if (id == 0) {
                row = table2.NewRow();
                table2.Rows.Add(row);
            }
            else {
                row = table2.Rows[k];
            }

            row[col1] = s.Symbol;
            row[col2] = s.Price;
            row[col3] = s.Change;

            k++;
            if (k == n) {
                k = 0;
                id++;
                col1 = table2.Columns.Add("Symbol_" + id, typeof(String));
                col2 = table2.Columns.Add("Price_" + id, typeof(decimal));
                col3 = table2.Columns.Add("Change_" + id, typeof(decimal));
            }
        }

        DataSource = table2;
        table.Dispose();
        table = table2;
        foreach (DataGridViewColumn c in Columns) {
            String t = c.HeaderText;
            int x = t.IndexOf('_');
            if (x < 0)
                continue;
            c.HeaderText = t.Substring(0, x);
        }
    }
}