dropDownList.Items.Insert(0, new ListItem("--请选择--", "-1"));
dropDownList.SelectedIndex = 1;
注意顺序即可.
dropDownList.Items.Insert(0, new ListItem("--请选择--", "-1"));
dropDownList.SelectedIndex = 1;
注意顺序即可.
转载于:https://www.cnblogs.com/ctautocn/p/4253955.html