//获取课程详细信息
        private void dataGridView1_MouseClick(object sender, MouseEventArgs e)
        {
            DataGridViewSelectedRowCollection selectedRow = this.dataGridView1.SelectedRows;

            foreach (DataGridViewRow row in selectedRow)
            {
                CourseInfo courseInfo = new CourseBusiness().getCourseInfobyCid(int.Parse(row.Cells["cid"].Value.ToString()));
                this.textBox1.Text = "课程简介: " + courseInfo.getBriefIntro();
            }
        }