//加载所有课程
public void BindAllCourse()
{
DALcourse dal = new DALcourse();
IList <courseEntity> courses = dal.Getcourses();
lb1.DataSource = courses;
lb1.DataTextField = "CourseName";
lb1.DataValueField = "Id";
lb1.DataBind();
}
/// <summary>
/// 加载已有的课程 ///
/// </summary>
public void BindCourse()
{
DropDownList1.Items.Clear();//避免重复加载
DALcourse dal = new DALcourse();
IList <courseEntity> courses = dal.Getcourses();
DropDownList1.DataSource = courses;
DropDownList1.DataTextField = "CourseName";
DropDownList1.DataValueField = "Id";
DropDownList1.DataBind();
DropDownList1.Items.Insert(0, new ListItem("请选择课程", "0"));
}