在绑定DropDownList时如果出现多次绑定，会出错以下错误：

“不能在DropDownList 中选择多个项”

经了解，只需要在选中值是清空选择即可：xxDropDownList.ClearSelection() ；

 

  /// <summary>

    /// 设定选中项

    /// </summary>

    /// <param name="list"></param>

    public static void SetListControl(ListControl list, string selectedValues)

    {

        if (string.IsNullOrEmpty(selectedValues))

            return;

        list.ClearSelection();

        foreach (string var in selectedValues.Split(','))

        {

            string value = var.Trim();

            if (value.Length > 0)

            {

                foreach (ListItem item in list.Items)

                {

                    if (item.Value == value)

                    {

                        item.Selected = true;

                        break;

                    }

                }

            }

        }

    }