一:将数据绑定到dataGridView控件上。

string sqlconn = "server=.;database=student;integrated security=true";
            try
            {
                string sqlcom = "select * from student_info";
                SqlConnection conn = new SqlConnection(sqlconn);
                SqlDataAdapter da = new SqlDataAdapter(sqlcom, conn);
                DataSet ds = new DataSet();
                da.Fill(ds);
                dataGridView1.DataSource = ds.Tables[0].DefaultView;
                dataGridView1.AllowUserToAddRows = false;
                conn.Close();
            }    

二:点击dataGridView的某一行将改行数据对应显示在textBox上。

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            try
            {
                snoTextBox.Text = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells["stu_sno"].Value.ToString();
                nameTextBox.Text = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells["stu_name"].Value.ToString();
                sexTextBox.Text = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells["stu_sex"].Value.ToString();
                ageTextBox.Text = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells["stu_age"].Value.ToString();
            }
            catch (Exception a)
            {
                MessageBox.Show(a.ToString());
            }
        }