Here is my code..
if (ds.Tables.Count > 0)
{
if (ds.Tables["ClsIndex"].Rows.Count > 0)
{
dataGrdBenClassIndex.Columns.Clear();
dataGrdBenClassIndex.AutoGenerateColumns = false;
dataGrdBenClassIndex.DataSource = ds.Tables[0];
DataGridViewTextBoxColumn classColumn = new DataGridViewTextBoxColumn();
classColumn.HeaderText = "Class";
classColumn.Name = "CLASS";
classColumn.Width = 150;
classColumn.DataPropertyName = "Class";
classColumn.CellTemplate = new DataGridViewTextBoxCell();
classColumn.ReadOnly = false;
classColumn.ToolTipText = "Double Click this cell to change the class name";
classColumn.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleCenter;
dataGrdBenClassIndex.Columns.Add(classColumn);
DataGridViewComboBoxColumn typeColumn = new DataGridViewComboBoxColumn();
typeColumn.Name = "TYPE";
typeColumn.DataPropertyName = "Type";
typeColumn.DisplayMember = "Type";
typeColumn.DataSource = ds.Tables[0];
typeColumn.HeaderText = "Type";
typeColumn.ValueType = typeof(string);
typeColumn.DisplayStyle = DataGridViewComboBoxDisplayStyle.ComboBox;
typeColumn.Width = 220;
typeColumn.SortMode = DataGridViewColumnSortMode.NotSortable;
typeColumn.Sorted = false;
typeColumn.ReadOnly = false;
typeColumn.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleCenter;
typeColumn.ToolTipText = "Please select Type";
dataGrdBenClassIndex.Columns.Add(typeColumn);
}
}