See the following code, hope it helps you:
protected void Timer1_Tick(object sender, EventArgs e)
{
FillDataGridView();
}
protected void FillDataGridView()
{
DataSet objDs = new DataSet();
SqlConnection myConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["Test"].ConnectionString);
SqlDataAdapter myCommand;
string select = "SELECT * FROM Table1";
myCommand = new SqlDataAdapter(select, myConnection);
myCommand.SelectCommand.CommandType = CommandType.Text;
myConnection.Open();
myCommand.Fill(objDs);
GridView1.DataSource = objDs;
GridView1.DataBind();
}