Devexpress GridControl 设置combobox下拉框

GridControl 设置combobox下拉框  

//设置combobox下拉框
        private void GetComboBox(string str)
        {
            RepositoryItemComboBox combobox = new RepositoryItemComboBox();
            combobox.Items.Add(str);
            combobox.AllowNullInput = DevExpress.Utils.DefaultBoolean.False;
            gridControl1.RepositoryItems.Add(combobox);
            this.gridView1.Columns["Product"].ColumnEdit = combobox;
        }