/// <summary> /// 班级变化 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void cmbClass_SelectedIndexChanged(object sender, EventArgs e) { if (cmbClass.Text != "") { string classId = ((DataTable)(cmbClass.DataSource)).Rows[cmbClass.SelectedIndex]["ClassId"].ToString(); DataSet ds_lesson = new DataSet(); if (db.GetLesson(0, 0, "*", "ClassId=" + classId, "", ref ds_lesson)) { cmbLesson.DataSource = ds_lesson.Tables[0]; cmbLesson.DisplayMember = "LessonName"; } else { cmbLesson.Text = ""; cmbLesson.DataSource = null; } } }