private void AdminPlacement_Load(object sender, EventArgs e)

        {

            pobjconn.Open();

            SqlCommand pobjcom = new SqlCommand();

            pobjcom.CommandText = "select CourseName,ElectivesID from View_1";

            pobjcom.Connection = pobjconn;

            pobjcom.ExecuteNonQuery();

            SqlDataAdapter pobjdat = new SqlDataAdapter(pobjcom);

            pobjdat.Fill(table);

            comboBox1.DataSource = table;

            comboBox1.DisplayMember = "CourseName";

            comboBox1.ValueMember = "ElectivesID";

            pobjconn.Close();

        }



        private void button1_Click_1(object sender, EventArgs e)

        {

            table1.Clear();

            pobjconn.Open();

            SqlCommand pobjcom = new SqlCommand();

            pobjcom.CommandText = "select CourseName as 选修课,TeacherName as 教师,StuName as 学生 from AdminPlacement where ElectivesID=@ElectivesID";

            pobjcom.Parameters.Add("@ElectivesID", SqlDbType.Int).Value = comboBox1.SelectedValue;

            pobjcom.Connection = pobjconn;

            pobjcom.ExecuteNonQuery();

            SqlDataAdapter pobjdat1 = new SqlDataAdapter(pobjcom);

            pobjdat1.Fill(table1);

            dataGridView1.DataSource = table1;

            dataGridView1.AllowUserToAddRows = false;

            for (int j = 0; j < dataGridView1.Columns.Count; j++)

                dataGridView1.Columns[j].SortMode = DataGridViewColumnSortMode.NotSortable;

            pobjconn.Close();

            textBox1.Text = dataGridView1.Rows.Count.ToString();