How to create custom Datagridview ListBox (Multi Row) control

You can have more than one 1 in a datagridview's textbox. I would just use the cellformatting event to make my list. Simple example

DataTable dt = new DataTable(); private void Form1_Load(object sender, EventArgs e) { SqlCeConnection conn = new SqlCeConnection("data source='c:\\northwind.sdf'; mode=Exclusive;"); SqlCeDataAdapter da = new SqlCeDataAdapter("Select [Product Name] from Products", conn); da.FillSchema(dt, SchemaType.Mapped ); DataColumn col = new DataColumn("List"); dt.Columns.Add(col); dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells; dataGridView1.DataSource = dt; dataGridView1.Columns["List"].DefaultCellStyle.WrapMode = DataGridViewTriState.True; dataGridView1.Columns["List"].ReadOnly = true; da.Fill(dt); } private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e) { if (e.ColumnIndex == 1) { e.Value = "aa\nbb\ncc\ndd\nee\nff"; e.FormattingApplied = true; } }