how to get data grid view on button

if(e.Keychar == (char)13)
{
    string strSQLconnection = "Data Source=dbServer;Initial Catalog=testDB;Integrated Security=True";
    SqlConnection sqlConnection = new SqlConnection(strSQLconnection);
    SqlCommand sqlCommand = new SqlCommand("SELECT * FROM TABLENAME", sqlConnection);
    sqlConnection.Open();
 
    SqlDataReader reader = sqlCommand.ExecuteReader();
       
    GridView1.DataSource = reader;
    GridView1.DataBind();
    GridView1.Visible = true;
    GridView1.Focus();
}