新手求助，如何把这个查询变成一个类以便其它程式调用,这个类如何写以及调用。

//查询按钮单击事件
private void button1_Click(object sender, EventArgs e)
{
    if (textBox1.Text != "")
    {
        string connStr = "Data Source=.;Initial Catalog=test;User ID=sa;Password=root";
        SqlConnection conn = null;
        try
        {
            conn = new SqlConnection(connStr);
            conn.Open();
            string sql = "select * from course where name like '%“+ textBox1.Text.Trim() +"%'";
            SqlDataAdapter sda = new SqlDataAdapter(sql, conn);
            DataSet ds = new DataSet();
            sda.Fill(ds);
            dataGridView1.DataSource = ds.Tables[0];
        }
        catch (Exception ex)
        {
            MessageBox.Show("出现错误！" + ex.Message);
        }
        finally
        {
            if (conn != null)
            {
                conn.Close();
            }
        }
    }
}